Biz Dr Helio Salgado, Renata Lataro ve Mauro de Oliveira, kurulum işlemini sırasında cömert yardım için Ribeirão Preto, Sao Paulo ve Dr Ben Janssen, Kardiyovasküler Araştırma Enstitüsü Maastricht, Maastricht Üniversitesi, Üniversitesi Tıp Fakültesi ederim. Bu çalışma SDC FONDECYT hibe N ° 11090114 tarafından desteklenmiştir

Protokol Facultad de Medicina Clinica Alemana-Universidad del Desarrollo ve Etik Komitesi tarafından onaylandı. I. Dobutamin İnfüzyon hazırlamak <ol><li> 500 ug / ml dobutamin bir stok çözeltisi elde etmek için, steril distile su, 20 ml dobutamin 10 mg eritilir. -20 ° C&#39;de kısım ve mağaza Bu çözelti 3 ay için en azından kullanılabilir. </li><li> Oda sıcaklığında dobutamin stok çözeltisi bir kısım çözülme. </li><li> Dobutaminin (ug / ml) = vücut ağırlığı x 0.2: formül kullanılarak hesaplanır konsantrasyon dobutamin çalışma çözeltisi, elde etmek için, steril% 0.9 NaCI içinde dobutamin stok çözeltisi seyreltilir. </li><li> Dobutamin çalışma çözeltisi ile 1 ml şırınga 29Gx1 / 2 &quot;doldurun. </li><li> Bir 20 cm PE-10 tüp içine şırınga iğnesi yerleştirin. </li><li> Üreticinin talimatları izleyerek infüzyon pompası şırınga ayarlayın. </li><li> Bir adımda rampa infüzyon ayarlama6 adımlar için, her adım için 10 ul / dak artışla biçimi-to-adım. </li></ol> II. Basınç Sensörü hazırlanması <ol><li> En az 15 dakika boyunca 37 ° C &#39;de steril su içinde sinyal kayması, batırmak basınç sensörü en aza indirilmesi. Bu hidrostatik basınç basınç sensörü etkiler önlemek için, daha fazla 0.5 cm derinliğinde kateter emmek etme. </li><li> Elektronik 25 ve 100 mmHg basınç sensörü kalibre. Elektrik girişi (Volt) basınç sinyali (mmHg) dönüştürülür. </li><li> 2 k / s örnekleme hızı ayarlayın ve 100 Hz&#39;de kesilerek filtre alçak geçiren kullanın. Basınç sinyali sıfıra mmHg olarak ayarlayın. </li><li> Sonda ucundan 15 mm işaretleyin. Giriş noktasından kalp ulaşmak için Distant sol ventrikül içine kateter varlığı tespit, ekokardiyografi ile tahmin edilmiştir. </li></ol> III. Kateterizasyon için Fare hazırlanması <ol><li> Ağırlık C57BL / 6 erkek fareler, haftalık 30-32. </li><li> Intraperitoneal 60 mg / kg ketamin ve 4 mg / kg ksilazin 1 enjekte edilir. Not: Diğer anestezikler, örneğin, kullanılan olabilir: 350 - 450 mg / kg avertin, 50 mikrogram / ​​pentobarbital kg veya 1.5 - 2% izofluran 2-3. </li><li> Elektrikli ustura ile boyun Tıraş. </li><li> Isıtılmış bir izotermal ısıtma plakası üzerine sırtüstü pozisyonda anestezi fare yerleştirin. Kağıt bant ile bacaklarda sabitleyin. </li><li> Tam sedasyon onaylamak için bir ayak tutam gerçekleştirin. </li><li> Yavaşça vücut sıcaklığını izlemek için bir rektal prob yerleştirin. Vaselinized prob kullanılması önerilir. </li><li> Vücut ısısı 37 farklıysa ° C ± 0.5 ° C, ısıtma plakası yoluyla ayarlayabilirsiniz. </li><li> Oksijen kaynağı yakınında fare burun koyun. </li><li> Stereomikroskop altında fare boyun bölgesinde yerleştirin. </li></ol> IV. Veri Toplama <ol><li> LabChartPro 7 yazılımı, basınç kayıt için tek kanallı ve kalp hızı için bir kanal (İK) seçinkaydı. Ikincisi için, seçenek &quot;Döngüsel Ölçümleri&quot; ve hızı gibi kurulum ölçümü seçin. </li><li> 0 ila 150 mmHg: basınç kanalı için ölçek aralığı ayarlayın. </li><li> 200 ila 600 bpm For: HR kanal ölçek aralığı ayarlayın. </li><li> Kayıt başlamak için start tuşuna basınız. </li><li> Prosedürleri, örneğin yapılan gösteren yorumlarla takın: anestezi yönetimi, değişiklikler solunum, dobutamin infüzyonu, dobutamin konsantrasyon başlar. </li></ol> V. Kalp Kateterizasyonu 4,5 <ol><li> Çene yakın sağ tarafında küçük bir kesi yapın. Makas deri-kas bağ dokusu ayırmak ile. </li><li> Trakeanın sağ tarafta - bir uzunlamasına diseksiyon (2 cm 1.5) gerçekleştirin. Trakea yakınındaki sağ karotis arter ortaya koymak için, kavisli bir forseps ile bağ dokusu, yağ ve kas ayırın. </li><li> Karotis arter maruz hayvan sağ tarafına bir genişletici yerleştirin. Vurmalıkalp tarafından oluşturulan basınç arter tarafından bulunması kolaylaşmaktadır. Koyu kırmızı juguler ven, sağ tarafta. </li><li> Kavisli bir forseps ile bitişik dokulardan arter ayırın. Bir beyaz ipliği andıran vagus siniri, arter boyunca yatıyor. </li><li> 6/0 ipek iplik ve &quot;çift&quot; bir 20 cm parça kesin. </li><li> Soldan sağa arter altındaki &quot;çift&quot; iplik geçirin. Ayrı ayrı uçları elde etmek için, iplik kes. </li><li> Arter altında üçüncü bir iş parçacığı (10 cm) Min. </li><li> Başlığına yakın konumlandırılmış parçacığı sıkı bir düğüm ve daha distal iplik gevşek bir tek bağla. </li><li> Orta iplik gevşek bir düğüm ve bir kağıt bant ile ısıtma pedi için orta iplik sağ ucunu sabitleyin. </li><li> Steril% 0.9 NaCl bırakarak karotis arter nemli tutun. Pamuk tomurcukları ile sıvı aşırı kurumasını bekleyin. </li><li> Bir hemostat klemp ile alt iplik gerin. </li><li> P hemostat makas konumunu saptamakkan akışı tıkamak için, karın derisi Santimleme üst iplik germe. Arter çevresinde bağ dokusu çıkarıldığından emin olun. Arter kan dolu ve nabız yoksun olmalıdır. Arter üzerinde bir tork kuvveti üreten Konuları önleyin. </li><li> Bir Vannas mikro-makas ile arterin alt kısmına yakın bir kesit nick olun. Kan damlaları dökülen edilecektir. </li><li> Karotis arter içine kateter yerleştirin. Tüm basınç sensörü tanıtmak için emin olun. Hiçbir kan kaybı olduğunu doğrulayın. </li><li> Nazikçe yerinde tutmak kateter için, orta düğüm iplik ayarlayın. Çok fazla sıkıştırmak etmeyin, basınç sensörü çok kırılgandır. </li><li> Hayvanın karın hemostat makas bırakın. </li><li> Kan kaybını önlemek için, el ile kateter tutun ve orta iplik itme. Not: arter kan dolu olmalıdır. </li><li> Kaydı basınç sinyalleri başlayın. </li><li> Kateter içinde olduğunda,arteriyel basınç sinyali 60-70 100-120 mmHg dalgalanır. Basıncı sinyalinin şekli Şekil 1.A. Not gösterilmiştir: Eğer ilgilenen varsa sinyal en az 5 dakika boyunca sabit ise, bu kez noktada arter basıncı kaydedebilirsiniz. HR değerleri kayıt sinyali 30 saniye arayla dikkate basınç dalga elde edilmiştir. Bu soruşturma hedefleri doğrultusunda, İK doğrudan ölçümü için de bir EKG yöntemi kullanmak mümkündür. </li><li> Yavaşça basınç sinyali (Şekil 1.B) şeklinde bir değişiklik gözlemlemek için kateter yukarıya doğru itilir. Kateter sol ventrikül içine sonra, basınç sinyali 0 100-120 mmHg dalgalanır. Bu kateter kaydırın zor ise, iki parmak ile hayvan göğüs çimdik. </li><li> Sürekli nefes hızı, vücut ısısı, anestezi seviyesi ve basınç sinyalini kontrol. Hepsi de sabit kalmalıdır. </li></ol> VI. Dobutamin infüzyonu <ol><li&gt; Juguler ven kateterizasyonu için onun perforasyonu önlemek amacıyla, damar çevresinde geri soyma adipoz doku emin olun. Ven oklüzyonu için cerrahi prosedür karotid arter için gösterilen prosedüre benzer. </li><li> Damar içine PE-10 tüp tanıtın. Kan akımı onaylayın geriye şırınganın pistonu hareket engellenmez. </li><li> Dobutamin infüzyonu 10 ul / dk ile başlar ve 60 ul / dk ile bitiriyoruz. Her adımda, infüzyon hızı 2 dakika 6 için korunur. </li><li> Son dobutamin dozdan sonra, anestezi, bir doz aşımı ile hayvan ötenazi. </li></ol> VII. Veri Analizi <ol><li> Veri analizi için, ilgi kayıtlı veri bölümünü seçin. Basınç sinyali stabil olduğu bir zaman aralığı dikkate aldığınızdan emin olun. </li><li> Kan Basıncı modülü Kurulum simgesini seçin. Basıncı sinyalinin seçilen türü belirtin. </li><li> Otomatik LabChartPro 7 yazılımı görüntüler demek, maksimumve HR için minimum değerler, sistolik basıncı (P max), diyastolik kan basıncı (P min), diyastol sonu basıncı (EDP), maksimal pozitif basınç gelişimi (dP / dtmax) ve maksimal negatif basınç gelişimi (dP / dt min). Buna ek olarak, kalp parametrelerini basınç izleme üzerinde tasvir edilebilir. </li></ol>

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	<li>Hart, C. Y., Burnett, J. C., Redfield, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+avertin+versus+xylazine-ketamine+anesthesia+on+cardiac+function+in+normal+mice.">Effects of avertin versus xylazine-ketamine anesthesia on cardiac function in normal mice.</a> Am. J. Physiol. Heart Circ. Physiol. 281, H1938-H1945 (2001).</li><li>Janssen, B. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+anesthetics+on+systemic+hemodynamics+in+mice.">Effects of anesthetics on systemic hemodynamics in mice.</a> Am. J. Physiol. Heart Circ. Physiol. 287, H1618-H1624 (2004).</li><li>Lorenz, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+guide+to+evaluating+cardiovascular,+renal,+and+pulmonary+function+in+mice.">A practical guide to evaluating cardiovascular, renal, and pulmonary function in mice.</a> Am. J. Physiol. Regul. Integr. Comp. Physiol. 282, R1565-R1582 (2002).</li><li>Lorenz, J. N., Robbins, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+intraventricular+pressure+and+cardiac+performance+in+the+intact+closed-chest+anesthetized+mouse.">Measurement of intraventricular pressure and cardiac performance in the intact closed-chest anesthetized mouse.</a> Am. J. Physiol. 272, H1137-H1146 (1997).</li><li>Nemoto, S., DeFreitas, G., Carabello, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+catheterization+technique+in+a+closed-chest+murine+model.">Cardiac catheterization technique in a closed-chest murine model.</a> Contemp. Top. Lab Anim. Sci. 42, 34-38 (2003).</li><li>Daniels, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impaired+cardiac+functional+reserve+in+type+2+diabetic+db/db+mice+is+associated+with+metabolic,+but+not+structural,+remodelling.">Impaired cardiac functional reserve in type 2 diabetic db/db mice is associated with metabolic, but not structural, remodelling.</a> Acta Physiol. (Oxf). 200, 11-22 (2010).</li><li>De Celle, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+structural+and+functional+consequences+of+cardiac+ischaemia-reperfusion+injury+in+vivo+in+mice.">Long-term structural and functional consequences of cardiac ischaemia-reperfusion injury in vivo in mice.</a> Exp. Physiol. 89, 605-615 (2004).</li><li>Huntgeburth, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transforming+growth+factor+beta+oppositely+regulates+the+hypertrophic+and+contractile+response+to+beta-adrenergic+stimulation+in+the+heart.">Transforming growth factor beta oppositely regulates the hypertrophic and contractile response to beta-adrenergic stimulation in the heart.</a> PLoS One. 6, e26628 (2011).</li><li>Reddy, A. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+function+in+young+and+old+Little+mice.">Cardiac function in young and old Little mice.</a> J. Gerontol. A. Biol. Sci. Med. Sci. 62, 1319-1325 (2007).</li><li>Christoffersen, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+lipid+accumulation+associated+with+diastolic+dysfunction+in+obese+mice.">Cardiac lipid accumulation associated with diastolic dysfunction in obese mice.</a> Endocrinology. 144, 3483-3490 (2003).</li></ol>

Çıkar çatışması ilan etti.

Dobutamin ile tetiklenen ve kardiyak kateterizasyon ile takip Kalp stres testi zahmetli. Bununla birlikte, burada protokolü takip tanımlamak ve eğitim kısa bir süre ile, tek bir deneyde geçen yaklaşık bir saat içinde altı hemodinamik parametreleri değerlendirmek mümkündür. Sunulan burada protokol kritik adımlar kan damarlarının cannulations vardır. Karotid arter kanülasyonu ile ilgili olarak, yapılan kesi üç doku arter katmanları, ve kateter geçişine izin vermek içi...

<table border="1"><tbody><tr><td></td><td></td><td></td><td> Reaktifler </td></tr><tr><td> PE-50/10 </td><td> Warner Instruments </td><td> 64-0752 </td><td></td></tr><tr><td> İpek ipliği 6/0 HR17 </td><td> Tagum </td><td> SN0713K </td><td></td></tr><tr><td> Xylacin 20 mg / ml </td><td> Laboratorio Centrovet </td><td></td><td></td></tr><tr><td> Ketamin 100 mg / ml </td><td> Sürükle Pharma </td><td></td><td></td></tr><tr><td> Sodyum klorür% 0.9 &#39; </td><td> Lab Sanderson SA </td><td></td><td></td></tr><tr><td> Dobutamin hidroklorür </td><td> Sigma-Aldrich </td><td> D0676 </td><td></td></tr><tr><td> Şırınga U-100 İnsülin 29G x ½ &quot; </td><td> Terumo Medical Co </td><td></td><td></td></tr><tr><td> Mikro 11,5 cm Stil 7 Diseksiyon Forseps </td><td> LawtonMedizintechnik </td><td> 09-0959 </td><td></td></tr><tr><td> Graefe Forseps CVD 0.7mm 7cm </td><td> Lawton Medizintechnik </td><td> 62-0263 </td><td></td></tr><tr><td> Kelepçeleri Dieffenbach bulldog Cl Str 38 mm </td><td> Lawton Medizintechnik </td><td> 60-010 </td><td></td></tr><tr><td> Vannas Makas 8 cm Str Fh </td><td> Lawton Medizintechnik </td><td> 63-1400 </td><td></td></tr><tr><td></td><td></td><td></td><td> Ekipman </td></tr><tr><td> SPR-671 Mikro-Tip Basınç kateter </td><td> Millar aletleri </td><td> 840-6719 </td><td></td></tr><tr><td> PKB-2000 Basınç Kontrol Ünitesi </td><td> Millar aletleri </td><td> 880-0129 </td><td></td></tr><tr><td> PowerLab 4/30 </td><td> ADinstruments Pty Ltd </td><td> ML866 </td><td></td></tr><tr><td> LabChartPro 7 </td><td> ADinstruments Pty Ltd </td><td> MLU260 / 7 </td><td></td></tr><tr><td> Legato200 İnfüzyon Pompası </td><td> KdScientific </td><td> KD-KDS210P </td><td></td></tr><tr><td> Tcat-2LV Sıcaklık kontrolörü ve izotermal ısıtma plakası </td><td> PhysiTemp aletleri A.Ş. </td><td></td><td></td></tr><tr><td> Medikal Oksijen kaynağı </td><td> Indura </td><td></td><td></td></tr><tr><td> Rektal prob </td><td> ADinstruments Pty Ltd </td><td> MLT1404 </td><td></td></tr><tr><td> Trinoküler Mikroskop, eksenel aydınlatma </td><td> LW Scientific </td><td> Z2B-TRI-ETNE, ILP-1502-LTS1, ILP-1502-DGGF </td><td></td></tr></tbody></table>

cardiac stress test induced by dobutamine and monitored by cardiac catheterization in mice

Dobutamin arter (β 2) olarak ifade reseptörlerine göre kalp (β 1) olarak ifade reseptörü için yüksek bir afiniteye sahip bir β-adrenerjik agonistidir. Sistemik olarak uygulandığında, kardiyak tüketimini artırır. Böylece, dobutamin potansiyel enfarktüs riski anormal ritmi veya iskemik alanlar unmasks. Bir kardiyak stres testi sırasında kalp fonksiyonlarının izlenmesi ekokardiyografi veya kalp kateterizasyonu da yapılabilir. İkincisi bu eski bir invaziv, ancak daha doğru ve bilgilendirici bir tekniktir. Kalp atım hızı (KAH), sistolik basınç, diyastolik basınç, diyastol sonu basıncı, maksimal pozitif basınç: Kalp stres testi dobutamin ile tetiklenen ve burada açıklandığı gibi başarılı kardiyak kateterizasyon tarafından izlenen tek bir deneyde, aşağıdaki hemodinamik parametrelerin ölçümünde, izin geliştirme (dP / dtmax) ve maksimal olumsuz basınure geliştirme (dP / dt min), bazal şartlarda ve dobutamin artan dozlarda altında. Beklendiği gibi, normal farelerin biz İK, dP / dt max ve dP / dt min bir dobutamin doza bağlı artış gözlendi. Ayrıca, en yüksek dozda, yüksek yağ içerikli diyet ile endüklenen aşırı şişman farelerde kalp dekompensasyon ortaya çıkmasından sonra (12 ng / g / dak) test edilmiştir.

Arteriyel basınç sinyali sistolik ve diyastolik kan basıncı ile tanımlanır. Basınç sensörü sol ventrikül içinde olduğunda, onun basınç (LVP) dalga diyastolik basınç sıfır bir damla ve ventrikül kasılma öncesinde sol atriyal kasılma (Şekil 1) ile karakterizedir. Mevcut durum, ketamin-ksilazin anestezisi normal farelerin 280 HR ± 24, 107 P maks ± 8, 5 P dk ± 1, 14 ± 2 EDP, dP / 6081 dt max ± 365 ve dP / dt min vardı 5230 ± 526. </p...

Watch this Scientific Journal Video about Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice at JoVE.com

Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice

Biz dobutamin ile tetiklenen ve normal farelerde kalp kateterizasyonu tarafından izlenen bir kardiyak stres testi gerçekleştirmek için protokol açıklar. Ayrıca yüksek yağlı diyet bağlı obez farelerde subklinik kardiyak hastalık meydana çıkarmak için uygulama göstermektedir.

Kardiyak Stres Testi Dobutamin İndüklemiş ve Farelerde Kalp Kateterizasyonu tarafından İzlenen

Dobutamine is a &beta;-adrenergic agonist with an affinity higher for receptor expressed in the heart (&beta;1) than for receptors expressed in the ...

cardiac-stress-test-induced-dobutamine-monitored-cardiac

Research

JoVE Journal

Medicine

17.9K Görüntüleme.  Clínica Alemana Universidad del Desarrollo. Biz dobutamin ile tetiklenen ve normal farelerde kalp kateterizasyonu tarafından izlenen bir kardiyak stres testi gerçekleştirmek için protokol açıklar. Ayrıca yüksek yağlı diyet bağlı obez farelerde subklinik kardiyak hastalık meydana çıkarmak için uygulama göstermektedir.

Video: Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice

Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, the RV is significantly affected in pulmonary diseases such as pulmonary artery hypertension (PAH). In addition, the RV is remarkably sensitive to cardiac pathologies, including left ventricular (LV) dysfunction, valvular disease or RV infarction4. To understand the role of RV in the pathogenesis of cardiac diseases, a reliable and noninvasive method to access the RV structurally and functionally is essential.
A noninvasive trans-thoracic echocardiography (TTE) based methodology was established and validated for monitoring dynamic changes in RV structure and function in adult mice. To impose RV stress, we employed a surgical model of pulmonary artery constriction (PAC) and measured the RV response over a 7-day period using a high-frequency ultrasound microimaging system. Sham operated mice were used as controls. Images were acquired in lightly anesthetized mice at baseline (before surgery), day 0 (immediately post-surgery), day 3, and day 7 (post-surgery). Data was analyzed offline using software.
Several acoustic windows (B, M, and Color Doppler modes), which can be consistently obtained in mice, allowed for reliable and reproducible measurement of RV structure (including RV wall thickness, end-diastolic&#160;and end-systolic dimensions), and function (fractional area change, fractional shortening, PA peak velocity, and peak pressure gradient) in normal mice and following PAC.
Using this method, the pressure-gradient resulting from PAC was accurately measured in real-time using Color Doppler mode and was comparable to direct pressure measurements performed with a Millar high-fidelity microtip catheter. Taken together, these data demonstrate that RV measurements obtained from various complimentary views using echocardiography are reliable, reproducible and can provide insights regarding RV structure and function. This method will enable a better understanding of the role of RV cardiac dysfunction.

Right ventricle (RV) dysfunction is critical to the pathogenesis of cardiovascular disease, yet limited methodologies are available for its evaluation. Recent advances in ultrasound imaging provide a noninvasive and accurate option for longitudinal RV study. Herein, we detail a step-by-step echocardiographic method using a murine model of RV pressure overload.

Transtorasik Ekokardiyografi ile Pulmoner Arter Konstrüksiyon Fare Modeli sağ ventrikül yapı ve fonksiyonlarının değerlendirilmesi

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, ...

Tıp

Noninvasive Assessment of Cardiac Abnormalities in Experimental Autoimmune Myocarditis by Magnetic Resonance Microscopy Imaging in the Mouse

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-&#945; 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-&#945; 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.

This study demonstrates the successful establishment of magnetic resonance microscopy imaging as a non-invasive tool to assess the cardiac abnormalities in mice affected with autoimmune myocarditis. The data indicate that the technique can be used to monitor the disease-progression in live animals.

Fare Manyetik Rezonans Görüntüleme Mikroskopi tarafından Deneysel Otoimmün Miyokardit Kardiyak anormallikler noninvaziv değerlendirilmesi

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events ...

Early Detection of Drug-Induced Renal Hemodynamic Dysfunction Using Sonographic Technology in Rats

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is estimated to contribute to 19- 25% of all clinical cases of acute kidney injury (AKI) in critically ill patients. AKI detection has historically relied on metrics such as serum creatinine (sCr) or blood urea nitrogen (BUN) which are demonstrably inadequate in full assessment of nephrotoxicity in the early phase of renal dysfunction. Currently, there is no robust diagnostic method to accurately detect hemodynamic alteration in the early phase of AKI while such alterations might actually precede the rise in serum biomarker levels. Such early detection can help clinicians make an accurate diagnosis and help in in decision making for therapeutic strategy. Rats were treated with Cisplatin to induce AKI. Nephrotoxicity was assessed for six days using high-frequency sonography, sCr measurement and upon histopathology of kidney. Hemodynamic evaluation using 2D and Color-Doppler images were used to serially study nephrotoxicity in rats, using the sonography. Our data showed successful drug-induced kidney injury in adult rats by histological examination. Color-Doppler based sonographic assessment of AKI indicated that resistive-index (RI) and pulsatile-index (PI) were increased in the treatment group; and peak-systolic velocity (mm/s), end-diastolic velocity (mm/s) and velocity-time integral (VTI, mm) were decreased in renal arteries in the same group. Importantly, these hemodynamic changes evaluated by sonography preceded the rise of sCr levels. Sonography-based indices such as RI or PI can thus be useful predictive markers of declining renal function in rodents. From our sonography-based observations in the kidneys of rats that underwent AKI, we showed that these noninvasive hemodynamic measurements may consider as an accurate, sensitive and robust method in detecting early stage kidney dysfunction. This study also underscores the importance of ethical issues associated with animal use in research.

Early stage hemodynamic dysfunction is critical to the development of kidney disease. Yet, detection methodologies are limited. Recent advances in sonography provide a noninvasive, accurate option for early detection of kidney injury. This study outlines a step-by-step, sonographic methodology for detecting kidney dysfunction using a drug-induced nephrotoxicity rat model.

Sıçanlarda sonografik Teknoloji Kullanımı İlaç Kaynaklı Böbrek Hemodinamik Bozukluğu Erken Tespiti

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is ...

Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these strategies is to examine their effects on heart function. There are several techniques to measure in vivo cardiac mechanics (e.g., echocardiography, pressure/volume relations, etc.). Compared to echocardiography, real-time left ventricular (LV) pressure/volume analysis via catheterization is more precise and insightful in assessing LV function. Additionally, LV pressure/volume analysis provides the ability to instantaneously record changes during manipulations of contractility (e.g., &#946;-adrenergic stimulation) and pathological insults (e.g., ischemia/reperfusion injury). In addition to the maximum (+dP/dt) and minimum (-dP/dt) rate of pressure change in the LV, an accurate assessment of LV function via several load-independent indexes (e.g., end systolic pressure volume relationship and preload recruitable stroke work) can be attained. Heart rate has a significant effect on LV contractility such that an increase in the heart rate is the primary mechanism to increase cardiac output (i.e., Bowditch effect). Thus, when comparing hemodynamics between experimental groups, it is necessary to have similar heart rates. Furthermore, a hallmark of many cardiomyopathy models is a decrease in contractile reserve (i.e., decreased Bowditch effect). Consequently, vital information can be obtained by determining the effects of increasing heart rate on contractility. Our and others data has demonstrated that the neuronal nitric oxide synthase (NOS1) knockout mouse has decreased contractility. Here we describe the procedure of measuring LV pressure/volume with increasing heart rates using the NOS1 knockout mouse model.

This article describes the measurement of murine left ventricular function via pressure/volume analysis at different heart rates.

Bowditch Efekt incelenmesi: Basınç Hacim İlişkisi Tedbir Fare Kardiyak Kateterizasyon

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these ...

Myocardial Infarction in Neonatal Mice, A Model of Cardiac Regeneration

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and regeneration, and to define new targets for therapeutics. For decades, models of complete heart regeneration existed in amphibians and fish, but a mammalian counterpart was not available. The recent discovery of a postnatal window during which mice possess regenerative capabilities has led to the establishment of a mammalian model of cardiac regeneration. A surgical model of mammalian cardiac regeneration in the neonatal mouse is presented herein. Briefly, postnatal day 1 (P1) mice are anesthetized by isoflurane and placed on an ice pad to induce hypothermia. After the chest is opened, and the left anterior descending coronary artery (LAD) is visualized, a suture is placed around the LAD to inflict myocardial ischemia in the left ventricle. The surgical procedure takes 10-15 min. Visualizing the coronary artery is crucial for accurate suture placement and reproducibility. Myocardial infarction and cardiac dysfunction are confirmed by triphenyl-tetrazolium chloride (TTC) staining and echocardiography, respectively. Complete regeneration 21 days post myocardial infarction is verified by histology. This protocol can be used to as a tool to elucidate mechanisms of mammalian cardiac regeneration after myocardial infarction.

This protocol describes a highly reproducible model of cardiac regeneration by surgical induction of myocardial infarction in the left ventricle of postnatal day 1 mice. The method involves induction of hypothermic anesthesia and ligation of the left anterior descending coronary artery.

Yenidoğan Farelerde Miyokard Enfarktüsü, Kalp Rejenerasyon Bir Model

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and ...

A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice

The circumlimbal suture is a technique for inducing experimental glaucoma in rodents by chronically elevating intraocular pressure (IOP), a well-known risk factor for glaucoma. This protocol demonstrates a step-by-step guide on this technique in Long Evans rats and C57BL/6 mice. Under general anesthesia, a "purse-string" suture is applied on the conjunctiva, around the equator and behind the limbus of the eye. The fellow eye serves as an untreated control. Over the duration of our study, which was a period of 8 weeks for rats and 12 weeks for mice, IOP remained elevated, as measured regularly by rebound tonometry in conscious animals without topical anesthesia. In both species, the sutured eyes showed electroretinogram features consistent with preferential inner retinal dysfunction. Optical coherence tomography showed selective thinning of the retinal nerve fiber layer. Histology of the rat retina in cross-section found reduced cell density in the ganglion cell layer, but no change in other cellular layers. Staining of flat-mounted mouse retinae with a ganglion cell specific marker (RBPMS) confirmed ganglion cell loss. The circumlimbal suture is a simple, minimally invasive and cost-effective way to induce ocular hypertension that leads to ganglion cell injury in both rats and mice.

Chronic ocular hypertension is induced by applying a circumlimbal suture in rats and mice, leading to functional and structural deterioration of the retinal ganglion cells consistent with glaucoma.

Manken Circumlimbal dikiş sıçanlar ve fareler tarafından indüklenen glokom

The circumlimbal suture is a technique for inducing experimental glaucoma in rodents by chronically elevating intraocular pressure (IOP), a well-known ...

Isolation of Atrial Myocytes from Adult Mice

The electrophysiological properties of atrial myocytes importantly affect overall cardiac function. Alterations in the underlying ionic currents responsible for the action potential can cause pro-arrhythmic substrates that underlie arrhythmias, such as atrial fibrillation, which are highly prevalent in many conditions and disease states. Isolating adult mouse atrial cardiomyocytes for use in patch-clamp experiments has greatly advanced our knowledge and understanding of the cellular electrophysiology in the healthy atrial myocardium and in the setting of atrial pathophysiology. In addition, studies using genetic mouse models have elucidated the role of a vast array of proteins in regulating atrial electrophysiology. Here we provide a detailed protocol for the isolation of cardiomyocytes from the atrial appendages of adult mice using a combination of enzymatic digestion and mechanical dissociation of these tissues. This approach consistently and reliably yields isolated atrial cardiomyocytes that can then be used to characterize cellular electrophysiology by measuring action potentials and ionic currents in patch-clamp experiments under a number of experimental conditions.

This protocol is used to isolate single atrial cardiomyocytes from the adult mouse heart using a chunk digestion approach. This approach is used to isolate right or left atrial myocytes that can be used to characterize atrial myocyte electrophysiology in patch-clamp studies.

Yetişkin fareler atriyal Miyoksit izolasyonu

The electrophysiological properties of atrial myocytes importantly affect overall cardiac function. Alterations in the underlying ionic currents ...

Biventricular Assessment of Cardiac Function and Pressure-Volume Loops by Closed-Chest Catheterization in Mice

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) generated by recording both pressure and volume during cardiac catheterization are vital when assessing both systolic and diastolic cardiac function. Left and right heart function are closely related, reflected in ventricular interdependence. Thus, recording biventricular function in the same animal is important to get a complete assessment of cardiac function. In this protocol, a closed chest approach to cardiac catheterization consistent with the way catheterization is performed in patients is adopted in mice. While challenging, the closed chest strategy is a more physiological approach, because opening the chest results in major changes in preload and afterload that create artifacts, most notably a fall in systemic blood pressure. While high-resolution echocardiography is used to assess rodents, cardiac catheterization is invaluable, particularly when assessing diastolic pressures in both ventricles.
Described here is a procedure to perform invasive, closed chest, sequential left and right ventricular pressure-volume (PV) loops in the same animal. PV loops are acquired using&#160;admittance technology with a mouse pressure-volume catheter and pressure-volume system acquisition. The procedure is described, beginning with the neck dissection, which is required to access the right jugular vein and the right carotid artery, to the insertion and positioning of the catheter, and finally the data acquisition. Then, the criteria required to ensure the acquisition of high-quality PV loops are discussed. Finally, the analysis of the left and right ventricular PV loops and the different hemodynamic parameters available to quantify systolic and diastolic ventricular function are briefly described.

Presented here is a protocol to assess biventricular heart function in mice by generating pressure-volume (PV) loops from the right and left ventricle in the same animal using closed chest catheterization. The focus is on the technical aspect of surgery and data acquisition.

Farelerde Kapalı Göğüs Kateterizasyonu ile Kardiyak Fonksiyon ve Basınç-Hacim Döngülerinin Biventriküler Değerlendirmesi

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) ...

Cardiac Response to &#946;-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis

Determination of the cardiac function is a robust endpoint analysis in animal models of cardiovascular diseases in order to characterize effects of specific treatments on the heart. Due to the feasibility of genetic manipulations the mouse has become the most common mammalian animal model to study cardiac function and to search for new potential therapeutic targets. Here we describe a protocol to determine cardiac function&#160;in vivo using pressure-volume loop measurements and analysis during basal conditions and under &#946;-adrenergic stimulation by intravenous infusion of increasing concentrations of isoproterenol. We provide a refined protocol including ventilation support taking into account the positive end-expiratory pressure to ameliorate negative effects during open-chest measurements, and potent analgesia (Buprenorphine) to avoid uncontrollable myocardial stress evoked by pain during the procedure. All together the detailed description of the procedure and discussion about possible pitfalls enables highly standardized and reproducible pressure-volume loop analysis, reducing the exclusion of animals from the experimental cohort by preventing possible methodological bias.

Cardiac Response to &amp;#946;-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis

Here we describe a cardiac pressure-volume loop analysis under increasing doses of intravenously infused isoproterenol to determine the intrinsic cardiac function and the &#946;-adrenergic reserve in mice. We use a modified open-chest approach for the pressure-volume loop measurements, in which we include ventilation with positive end-expiratory pressure.

Basınç-Hacim Döngüsü Analizi ile Belirlenen β-Adrenerjik Stimülasyona Kardiyak Yanıt

Determination of the cardiac function is a robust endpoint analysis in animal models of cardiovascular diseases in order to characterize effects of ...

A Large Animal Model for Acute Kidney Injury by Temporary Bilateral Renal Artery Occlusion

Acute kidney injury (AKI) is associated with higher risk for morbidity and mortality post-operatively. Ischemia-reperfusion injury (IRI) is the most common cause of AKI. To mimic this clinical scenario, this study presents a highly reproducible large animal model of renal IRI in swine using temporary percutaneous bilateral balloon-catheter occlusion of the renal arteries. The renal arteries are occluded for 60 min by introducing the balloon-catheters through the femoral and carotid artery and advancing them into the proximal portion of the arteries. Iodinated contrast is injected in the aorta to assess any opacification of the kidney vessels and confirm the success of the artery occlusion. This is furtherly confirmed by the flattening of the pulse waveform at the tip of the balloon catheters. The balloons are deflated and removed after 60 min of bilateral renal artery occlusion, and the animals are allowed to recover for 24 h. At the end of the study, plasma creatinine and blood urea nitrogen significantly increase, while eGFR and urine output significantly decrease. The need for iodinated contrast is minimal and does not affect renal function. Bilateral renal artery occlusion better mimics the clinical scenario of perioperative renal hypoperfusion, and the percutaneous approach minimizes the impact of the inflammatory response and the risk of infection seen with an open approach, such as a laparotomy. The ability to create and reproduce this clinically relevant swine model eases the clinical translation to humans.

This study presents a highly reproducible large animal model of renal ischemia-reperfusion injury in swine using temporary percutaneous bilateral balloon-catheter occlusion of the renal arteries for 60 min and reperfusion for 24 h.

Geçici bilateral Renal Arter Tıkanma ile Akut Böbrek Yaralanması için Büyük Bir Hayvan Modeli

Acute kidney injury (AKI) is associated with higher risk for morbidity and mortality post-operatively. Ischemia-reperfusion injury (IRI) is the most ...