ونحن نشكر الموظفين من "البحوث الطبية الفريد" وفريق "خدمات التعليم المخفر الحيوان" (AS أمريب) لما قدمته من المساعدة ورعاية الفئران المستخدمة في هذه الدراسة والدعم لنظام "دعم البنية التحتية التشغيلية" من الدولة الفيكتوري الحكومة.

<ol>
	<li>Chen, W., Wilson, J. L., Khaksari, M., Cowley, M. A., Enriori, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Abdominal+fat+analyzed+by+DEXA+scan+reflects+visceral+body+fat+and+improves+the+phenotype+description+and+the+assessment+of+metabolic+risk+in+mice.">Abdominal fat analyzed by DEXA scan reflects visceral body fat and improves the phenotype description and the assessment of metabolic risk in mice.</a> Am J Physiol Endocrinol Metab. 303 (5), E635-E643 (2012).</li><li>Kovner, I., Taicher, G. Z., Mitchell, A. 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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=Thermoneutral+housing+exacerbates+nonalcoholic+fatty+liver+disease+in+mice+and+allows+for+sex-independent+disease+modeling.">Thermoneutral housing exacerbates nonalcoholic fatty liver disease in mice and allows for sex-independent disease modeling.</a> Nat Med. 23 (7), 829-838 (2017).</li><li>Lee, M. W., 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=Activated+type+2+innate+lymphoid+cells+regulate+beige+fat+biogenesis.">Activated type 2 innate lymphoid cells regulate beige fat biogenesis.</a> Cell. 160 (1-2), 74-87 (2015).</li><li>Kusminski, C. 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=MitoNEET-driven+alterations+in+adipocyte+mitochondrial+activity+reveal+a+crucial+adaptive+process+that+preserves+insulin+sensitivity+in+obesity.">MitoNEET-driven alterations in adipocyte mitochondrial activity reveal a crucial adaptive process that preserves insulin sensitivity in obesity.</a> Nat Med. 18 (10), 1539-1549 (2012).</li><li>Judex, S., 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=Quantification+of+adiposity+in+small+rodents+using+micro-CT.">Quantification of adiposity in small rodents using micro-CT.</a> Methods. 50 (1), 14-19 (2010).</li><li>Chaurasia, B., 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=Adipocyte+ceramides+regulate+subcutaneous+adipose+browning,+inflammation,+and+metabolism.">Adipocyte ceramides regulate subcutaneous adipose browning, inflammation, and metabolism.</a> Cell Metab. 24 (6), 820-834 (2016).</li><li>Matthews, V. B., 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=Interleukin-6-deficient+mice+develop+hepatic+inflammation+and+systemic+insulin+resistance.">Interleukin-6-deficient mice develop hepatic inflammation and systemic insulin resistance.</a> Diabetologia. 53 (11), 2431-2441 (2010).</li><li>Tschop, M., Smiley, D. L., Heiman, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ghrelin+induces+adiposity+in+rodents.">Ghrelin induces adiposity in rodents.</a> Nature. 407 (6806), 908-913 (2000).</li><li>Garcia, M. 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=Mature-onset+obesity+in+interleukin-1+receptor+I+knockout+mice.">Mature-onset obesity in interleukin-1 receptor I knockout mice.</a> Diabetes. 55 (5), 1205-1213 (2006).</li><li>Kowalski, G. M., Bruce, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+regulation+of+glucose+metabolism:+Implications+and+considerations+for+the+assessment+of+glucose+homeostasis+in+rodents.">The regulation of glucose metabolism: Implications and considerations for the assessment of glucose homeostasis in rodents.</a> Am J Physiol Endocrinol Metab. 307 (10), E859-E871 (2014).</li><li>McGuinness, O. P., Ayala, J. E., Laughlin, M. R., Wasserman, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NIH+experiment+in+centralized+mouse+phenotyping:+the+Vanderbilt+experience+and+recommendations+for+evaluating+glucose+homeostasis+in+the+mouse.">NIH experiment in centralized mouse phenotyping: the Vanderbilt experience and recommendations for evaluating glucose homeostasis in the mouse.</a> Am J Physiol Endocrinol Metab. 297 (4), E849-E855 (2009).</li></ol>

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خطوات حاسمة
البروتوكولات المبينة في هذا التقرير تقديم مثال على طرق لقياس مكونات الجسم ومختلف المعايير الأيضية في الفئران باستخدام وهو محلل تكوين هيئة وحيوان ايضية نظام الرصد. لكل التقنيات، فمن الأهمية الحاسمة لضمان أن تعمل هذه الأجهزة على النحو الأمثل، للقيام به...

ويدعم الأيض جوانب كثيرة من الخلوي الطبيعي والجهاز وفسيولوجيا الجسم كله. ونتيجة لذلك، في الإعداد لمختلف الأمراض، تعديلات على التمثيل الغذائي قد تسهم مباشرة في الشرط الأساسي، أو قد يتأثر سلبا كأثر جانبي لعلم الأمراض. تقليديا، الأيضية للبحث والدراسات في ميزان الطاقة قد تركزت في مجال السمنة والشروط ذات الصلة مثل مقاومة الأنسولين، ما قبل السكري، التعصب السكر وأمراض القلب والأوعية الدموية، والسكري. هذه البحوث ما يبرره نظراً لتصاعد انتشار مثل هذه الشروط في جميع أنحاء العالم، والفرد، والمجتمعية، والتكاليف الاقتصادية تلحق هذه الشروط. على هذا النحو، وضع استراتيجيات وقائية وعلاجية جديدة للسمنة الهدف هدف مستمر في مختبرات البحوث في جميع أنحاء العالم، ونماذج الماوس الإكلينيكية بشدة الاعتماد على هذه الدراسات.
بينما تزن الفئران يوفر تقييم موثوق لزيادة الوزن أو الخسارة، فإنه لا يوفر توزيع للعناصر المختلفة التي تقوم بإنشاء تكوين الجسم كله (كتلة الدهون، الجماهيري الهزيل، والمياه مجاناً، فضلا عن عناصر أخرى مثل الفراء ومخالب). أن ترجيح منصات الدهون في استكمال الدراسات مرة واحدة الماوس المتوفى يوفر مقياس دقيق لمستودعات الدهون المختلفة بل يمكن فقط تقديم البيانات لنقطة مرة واحدة. نتيجة لذلك، من الضروري غالباً انتساب الأفواج المتعددة للتحقيق في وضع السمنة على مر الزمن، إلى حد كبير تزايد إعداد الحيوانات، والوقت والتكاليف. استخدام الأشعة السينية المزدوجة الطاقة absorptiometry (DEXA) يقدم نهجاً لتقييم محتويات الدهون والعجاف أنسجة الجسم ويسمح للباحث للحصول على البيانات بطريقة طولية. ومع ذلك، يتطلب الإجراء الفئران تخديره1، ونوبات متكررة من التخدير قد أثر تراكم الأنسجة الدهنية أو تؤثر على الجوانب الأخرى للتنظيم الأيضي. ويستخدم اتشومري ريلاكسوميتري الرنين المغناطيسي النووي لقياس كتلة الدهون والهزيل والماء مجاناً، والمحتوى الإجمالي للمياه. وهذا يمكن تحقيقه بسبب إنشاء التباين بين مكونات الأنسجة المختلفة، مع وجود اختلافات في المدة والسعة والتوزيع المكاني للترددات اللاسلكية التي تم إنشاؤها السماح بترسيم والتحديد الكمي لكل نوع من أنواع الأنسجة. هذا الأسلوب مفيد كما أنه غير الغازية، وسريعة وبسيطة ولا تتطلب أي التخدير أو الإشعاع و، الأهم من ذلك، قد تم إيجابيا التحقق من صحتها مقابل التحليل الكيميائي2.
هو أحد الاعتبارات رئيسية للسمنة والبحوث ذات الصلة معادلة توازن الطاقة. بينما تراكم الدهون أكثر تعقيداً من الطاقة بحتة في (تناول الطعام) مقابل الطاقة خارج (نفقات الطاقة)، وعوامل حيوية لتكون قادرة على قياس. نفقات الطاقة اليومية هو مجموع أربعة عناصر مختلفة: (1) نفقات الطاقة القاعدية (يستريح معدل الأيض)؛ (2) نفقات الطاقة نظراً لتأثير الحرارية لاستهلاك الأغذية؛ (3) الطاقة اللازمة ل thermoregulation؛ و (4) الطاقة تنفق على النشاط البدني. كما نفقات الطاقة يولد حرارة، قياس إنتاج الحرارة بحيوان (المعروفة باسم القياس المباشر) يمكن استخدامها لتقييم نفقات الطاقة. وبدلاً من ذلك، قياس الهم وانتهت تركيزات س2 و CO2، يسمح بتحديد الجسم كله س2 CO2 الإنتاج واﻻستهﻻك، يمكن أن تستخدم كوسيلة لقياس غير مباشر (غير المباشرة الحرارة إنتاج القياس) ونتيجة لذلك حساب نفقات الطاقة. زيادة في تناول الطعام أو انخفاض في نفقات الطاقة سوف تعرض الفئران لزيادة الوزن والملاحظات للتغييرات في هذه المعلمات يمكن أن توفر معلومات مفيدة من المحتمل آليات العمل في نماذج معينة من السمنة. معلمة ايضية ذات صلة للفائدة هو نسبة التبادل التنفسي (RER)، مؤشرا على النسبة من الركازة/الوقود (أي من الكربوهيدرات أو الدهون) التي تمر بها عملية التمثيل الغذائي، وتستخدم لإنتاج الطاقة. ونتيجة لذلك، يمكن أن توفر القياس لتناول الطعام (الطاقة المستهلكة) جنبا إلى جنب مع مستويات النشاط البدني واستهلاك2 س، RER ونفقات الطاقة فهم واسع الأيضية الشخصية كائن حي. أسلوب واحد لجمع مثل هذه البيانات هو استخدام حيوان مختبر شامل رصد نظام (البطلينوس)، التي تقوم على أسلوب القياس غير المباشر لقياس نفقات الطاقة ولديها قدرات إضافية لتحديد مستويات النشاط البدني (شعاع فواصل) وتناول الطعام عن طريق جداول إدراجها في غرفة القياس.
في هذا البروتوكول نقدم وصفاً مستقيم إلى الأمام لاستخدام هو محلل تكوين هيئة لتقييم تكوين الجسم في الفئران، ونظام رصد حيوان ايضية لقياس الجوانب المتعلقة بالتمثيل الغذائي. وستناقش الاعتبارات والقيود الخاصة بهذه التقنيات فضلا عن الأساليب المقترحة للتحليل والتفسير، وتمثيل البيانات.

<table><tbody><tr><td>4 in 1 system</td><td>EchoMRI</td><td>4 in 1 system</td><td>Whole body composition analyser</td></tr><tr><td>Canola oil test sample (COSTS)</td><td>EchoMRI</td><td>Mouse-specific (contact company for cat number)</td><td></td></tr><tr><td>Animal specimen holder&amp;nbsp;</td><td>EchoMRI</td><td>103-E56100R</td><td></td></tr><tr><td>Delimiter&amp;nbsp;</td><td>EchoMRI</td><td>600-E56100D</td><td></td></tr><tr><td>12 chamber system</td><td>Columbus Instruments</td><td>Custom built</td><td>Metabolic Caging System; includes control program</td></tr><tr><td>Drierite</td><td>Fisher Scientific</td><td>238988</td><td>CLAMS consumable</td></tr><tr><td>Calibration gas tank</td><td>Air Liquide</td><td>Mixed to order</td><td>Gas calibration (0.5% CO&lt;sub&gt;2&lt;/sub&gt;, 20.5% O&lt;sub&gt;2&lt;/sub&gt;, balance nitrogen).&amp;nbsp;</td></tr><tr><td>Normal chow diet</td><td>Specialty Feeds</td><td>Irradiated mouse and rat diet</td><td></td></tr><tr><td>High fat diet</td><td>Specialty Feeds</td><td>SF04-001</td><td></td></tr><tr><td>Balance</td><td>Mettler Toledo</td><td>PL202-S</td><td>Balance for weighing mice</td></tr><tr><td>TexQ Disinfectant spray</td><td>TexWipe</td><td></td><td></td></tr><tr><td>Hydrogen Peroxide cleaning solution</td><td>TexWipe</td><td>TX684</td><td></td></tr></tbody></table>

body composition and metabolic caging analysis in high fat fed mice

تعديلات على تكوين الجسم (كتلة الدهون أو الهزيل)، معلمات الأيضية مثل استهلاك الأوكسجين الجسم كله ونفقات الطاقة، واستخدام الركيزة، والسلوكيات مثل تناول الطعام والنشاط البدني يمكن أن توفر معلومات هامة بشأن الآليات الكامنة للمرض. ونظرا لأهمية تكوين الجسم والتمثيل الغذائي إلى تطور السمنة وعن عقابيل اللاحقة، من الضروري أن تجعل مقاييس دقيقة لهذه المعلمات في إعداد البحوث السريرية قبل. أوجه التقدم في التكنولوجيا على مدى العقود القليلة الماضية جعلت من الممكن اشتقاق هذه التدابير في نماذج القوارض بطريقة غير الغازية والطولية. ونتيجة لذلك، أثبتت هذه التدابير الأيضية مفيدة عند تقييم استجابة التلاعبات الجينية (الفئران على سبيل المثال الضربة القاضية أو المحورة وراثيا، والفيروسية ضربة إلى أسفل أو overexpression من الجينات)، وفحص المخدرات/مجمع التجريبية والغذائية، التدخلات السلوكية أو البدنية نشاط. وهنا، نحن تصف البروتوكولات المستخدمة لقياس مكونات الجسم والايض المعلمات باستخدام نظام الرصد في تشاو التي تغذيها وارتفاع الدهون الفئران حمية تغذية حيوان.

عرض النتائج ينظر في الشكل 3 تغيير نموذجي في معلمات تكوين الجسم عند تغذية الدهون عالية، كما يقاس عن طريق اتشومري. في الأساس لم يكن هناك فرق في أي معلمة قياسها (الشكل 3 ألف-F). ومع ذلك، بعد أسبوع واحد فقط من الدهون عالية التغذية، كان هن?...

Watch this Scientific Journal Video about Body Composition and Metabolic Caging Analysis in High Fat Fed Mice at JoVE.com

Body Composition and Metabolic Caging Analysis in High Fat Fed Mice

تكوين الجسم والتحليل الأيضي حبس في الفئران بنك الاحتياطي الفيدرالي الدهون عالية

ويصف هذا البروتوكول استخدام محلل تكوين الهيئة والأيضية نظام الرصد الحيوانية لتحديد خصائص تكوين الجسم والمعلمات الأيضي في الفئران. يتم استخدام نموذج السمنة الناجمة عن التغذية بالدهون كمثال لتطبيق هذه التقنيات.

Alterations to body composition (fat or lean mass), metabolic parameters such as whole-body oxygen consumption, energy expenditure, and substrate ...

body-composition-and-metabolic-caging-analysis-in-high-fat-fed-mice

Research

JoVE Journal

Medicine

15.3K Views.  Baker Heart and Diabetes Institute. ويصف هذا البروتوكول استخدام محلل تكوين الهيئة والأيضية نظام الرصد الحيوانية لتحديد خصائص تكوين الجسم والمعلمات الأيضي في الفئران. يتم استخدام نموذج السمنة الناجمة عن التغذية بالدهون كمثال لتطبيق هذه التقنيات.

Video: Body Composition and Metabolic Caging Analysis in High Fat Fed Mice

A Protocol for Housing Mice in an Enriched Environment

Environmental enrichment (EE) is a housing environment for mice that boosts mental and physical health compared to standard laboratory housing. Our recent studies demonstrate that environmental enrichment decreases adiposity, increases energy expenditure, resists diet induced obesity, and causes cancer remission and inhibition in mice. EE typically consists of larger living space, a variety of &#8216;toys&#8217; to interact with, running wheels, and can include a number of other novel environmental changes. All of this fosters a more complex social engagement, cognitive and physical stimulations. Importantly, the toy location and type of toy is changed regularly, which encourages the mice to adapt to a frequently changing and novel environment. Many variables can be manipulated in EE to promote health effects in mice. Thus these approaches are difficult to control and must be properly managed to successfully replicate the associated phenotypes. Therefore, the goal of this video is to demonstrate how EE is properly set up and maintained to assure a complex, challenging, and controlled environment so that other researchers can easily reproduce the protective effects of EE against obesity and cancer.

Environmental enrichment for mice requires a complex and challenging setup, as well as comprehensive husbandry and handling techniques to assure robust metabolic and anti-cancer effects in the mice. This protocol provides detailed procedures to reproduce the above mentioned effects in mice.

بروتوكول لالفئران الإسكان في بيئة المخصب

Environmental enrichment (EE) is a housing environment for mice that boosts mental and physical health compared to standard laboratory housing. Our recent ...

Behavior

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice

Type 2 diabetes is characterized by a defect in insulin action. The hyperinsulinemic-euglycemic clamp, or insulin clamp, is widely considered the "gold standard" method for assessing insulin action in vivo. During an insulin clamp, hyperinsulinemia is achieved by a constant insulin infusion. Euglycemia is maintained via a concomitant glucose infusion at a variable rate. This variable glucose infusion rate (GIR) is determined by measuring blood glucose at brief intervals throughout the experiment and adjusting the GIR accordingly. The GIR is indicative of whole-body insulin action, as mice with enhanced insulin action require a greater GIR. The insulin clamp can incorporate administration of isotopic 2[14C]deoxyglucose to assess tissue-specific glucose uptake and [3-3H]glucose to assess the ability of insulin to suppress the rate of endogenous glucose appearance (endoRa), a marker of hepatic glucose production, and to stimulate the rate of whole-body glucose disappearance (Rd).
The miniaturization of the insulin clamp for use in genetic mouse models of metabolic disease has led to significant advances in diabetes research. Methods for performing insulin clamps vary between laboratories. It is important to note that the manner in which an insulin clamp is performed can significantly affect the results obtained. We have published a comprehensive assessment of different approaches to performing insulin clamps in conscious mice1 as well as an evaluation of the metabolic response of four commonly used inbred mouse strains using various clamp techniques2. Here we present a protocol for performing insulin clamps on conscious, unrestrained mice developed by the Vanderbilt Mouse Metabolic Phenotyping Center (MMPC; URL: www.mc.vanderbilt.edu/mmpc). This includes a description of the method for implanting catheters used during the insulin clamp. The protocol employed by the Vanderbilt MMPC utilizes a unique two-catheter system3. One catheter is inserted into the jugular vein for infusions. A second catheter is inserted into the carotid artery, which allows for blood sampling without the need to restrain or handle the mouse. This technique provides a significant advantage to the most common method for obtaining blood samples during insulin clamps which is to sample from the severed tip of the tail. Unlike this latter method, sampling from an arterial catheter is not stressful to the mouse1. We also describe methods for using isotopic tracer infusions to assess tissue-specific insulin action. We also provide guidelines for the appropriate presentation of results obtained from insulin clamps.

The hyperinsulinemic-euglycemic clamp, or insulin clamp, is the gold standard for assessing insulin action in vivo. A method for performing insulin clamps in mice is described. This includes a method for arterial catheterization that permits experiments to be performed in conscious, unrestrained mice with minimal stress.

Hyperinsulinemic - سوي سكر الدم في الفئران المشابك ، وإدراكا بلا حدود

Type 2 diabetes is characterized by a defect in insulin action. The hyperinsulinemic-euglycemic clamp, or insulin clamp, is widely considered the "gold ...

Segmentation and Measurement of Fat Volumes in Murine Obesity Models Using X-ray Computed Tomography

Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are associated with obesity, though the precise underlying mechanisms that contribute to the disease are currently being delineated.2,3 Several small animal models of obesity have been developed and are employed in a variety of studies.4 A critical component to these experiments involves the collection of regional and/or total animal fat content data under varied conditions.
Traditional experimental methods available for measuring fat content in small animal models of obesity include invasive (e.g. ex vivo measurement of fat deposits) and non-invasive (e.g. Dual Energy X-ray Absorptiometry (DEXA), or Magnetic Resonance (MR)) protocols, each of which presents relative trade-offs. Current invasive methods for measuring fat content may provide details for organ and region specific fat distribution, but sacrificing the subjects will preclude longitudinal assessments. Conversely, current non-invasive strategies provide limited details for organ and region specific fat distribution, but enable valuable longitudinal assessment. With the advent of dedicated small animal X-ray computed tomography (CT) systems and customized analytical procedures, both organ and region specific analysis of fat distribution and longitudinal profiling may be possible. Recent reports have validated the use of CT for in vivo longitudinal imaging of adiposity in living mice.5,6 Here we provide a modified method that allows for fat/total volume measurement, analysis and visualization utilizing the Carestream Molecular Imaging Albira CT system in conjunction with PMOD and Volview software packages.

Fat content analysis is routinely conducted in studies utilizing murine obesity models. Emerging methods in small animal CT imaging and analysis are providing for longitudinal detail rich fat content analysis. Here we detail step by step procedures for performing small animal CT imaging, analysis, and visualization.

تجزئة والقياس من وحدات تخزين الدهون في الفئران نماذج السمنة عن طريق الأشعة السينية التصوير المقطعي

Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are ...

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Establishing a system of procedures to qualitatively and quantitatively characterize in vivo and in vitro hepatic steatosis is important for metabolic study in the liver. Here, numerous assays are described to comprehensively measure the phenotype and parameters of hepatic steatosis in mouse and hepatocyte models. 
Combining the physiological, histological, and biochemical methods, this system can be used to assess the progress of hepatic steatosis. In vivo, the measurements of body weight and nuclear magnetic resonance (NMR) provide a general understanding of mice in a non-invasive manner. Hematoxylin and Eosin (H&amp;E) and Oil Red O staining determine the histological morphology and lipid deposition of liver tissue under nutrient overload conditions, such as high-fat diet feeding. Next, the total lipid contents are isolated by chloroform/methanol extraction, which are followed by a biochemical analysis for triglyceride and cholesterol. Moreover, mouse primary hepatocytes are treated with high glucose plus insulin to stimulate lipid accumulation, an efficient in vitro model to mimic diet-induced hyperglycemia and hyperinsulinemia in vivo. Then, the lipid deposition is measured by Oil Red O staining and chloroform/methanol extraction. Oil Red O staining determines intuitive hepatic steatotic phenotypes, while the lipid extraction analysis determines the parameters that can be analyzed statistically. The present protocols are of interest to scientists in the fields of fatty liver diseases, insulin resistance, and type 2 diabetes.

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Here, optimized methods to generate in vivo and in vitro models of hepatic steatosis and to analyze the steatotic phenotypes and related physiological parameters are described.

تحليل الأمثل ل<em&gt; في فيفو</em&gt; و<em&gt; في المختبر</em&gt; كبدي تشحم

Establishing a system of procedures to qualitatively and quantitatively characterize in vivo and in vitro hepatic steatosis is important for metabolic ...

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)

Obesity represents the most important single risk factor in the pathogenesis of type 2 diabetes, a disease which is characterized by a resistance to insulin-stimulated glucose uptake and a gross decompensation of systemic glucose metabolism. Despite considerable progress in the understanding of glucose metabolism, the molecular mechanisms of its regulation in health and disease remain under-investigated, while novel approaches to prevent and treat diabetes are urgently needed. Diet derived glucose stimulates the pancreatic secretion of insulin, which serves as the principal regulator of cellular anabolic processes during the fed-state and thus balances blood glucose levels to maintain systemic energy status. Chronic overfeeding triggers meta-inflammation, which leads to alterations in peripheral insulin receptor-associated signaling and thus reduces the sensitivity to insulin-mediated glucose disposal. These events ultimately result in elevated fasting glucose and insulin levels as well as a reduction in glucose tolerance, which in turn serve as important indicators of insulin resistance. Here, we present a protocol for the generation and metabolic characterization of high-fat diet (HFD)-fed mice as a frequently used model of diet-induced insulin resistance. We illustrate in detail the oral glucose tolerance test (OGTT), which monitors the peripheral disposal of an orally administered glucose load and insulin secretion over time. Additionally, we present a protocol for the insulin tolerance test (ITT) to monitor whole-body insulin action. Together, these methods and their downstream applications represent powerful tools to characterize the general metabolic phenotype of mice as well as to specifically assess alterations in glucose metabolism. They may be especially useful in the broad research field of insulin resistance, diabetes and obesity to provide a better understanding of pathogenesis as well as to test the effects of therapeutic interventions.

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test OGTT and Insulin Tolerance Test ITT

The current article describes the generation and metabolic characterization of high-fat diet-fed mice as a model of diet-induced insulin resistance and obesity. It further features detailed protocols to perform the oral glucose tolerance test and the insulin tolerance test, monitoring whole-body alterations of glucose metabolism in vivo.

دراسة في فيفو أيض الجلوكوز في الفئران تغذية حمية عالية الدهون باستخدام اختبار تحمل الجلوكوز عن طريق الفم (OGTT) واختبار تحمل الأنسولين (ITT)

Obesity represents the most important single risk factor in the pathogenesis of type 2 diabetes, a disease which is characterized by a resistance to ...

Biochemical and High Throughput Microscopic Assessment of Fat Mass in Caenorhabditis Elegans

The nematode C. elegans has emerged as an important model for the study of conserved genetic pathways regulating fat metabolism as it relates to human obesity and its associated pathologies. Several previous methodologies developed for the visualization of C. elegans triglyceride-rich fat stores have proven to be erroneous, highlighting cellular compartments other than lipid droplets. Other methods require specialized equipment, are time-consuming, or yield inconsistent results. We introduce a rapid, reproducible, fixative-based Nile red staining method for the accurate and rapid detection of neutral lipid droplets in C. elegans. A short fixation step in 40% isopropanol makes animals completely permeable to Nile red, which is then used to stain animals. Spectral properties of this lipophilic dye allow it to strongly and selectively fluoresce in the yellow-green spectrum only when in a lipid-rich environment, but not in more polar environments. Thus, lipid droplets can be visualized on a fluorescent microscope equipped with simple GFP imaging capability after only a brief Nile red staining step in isopropanol. The speed, affordability, and reproducibility of this protocol make it ideally suited for high throughput screens. We also demonstrate a paired method for the biochemical determination of triglycerides and phospholipids using gas chromatography mass-spectrometry. This more rigorous protocol should be used as confirmation of results obtained from the Nile red microscopic lipid determination. We anticipate that these techniques will become new standards in the field of C. elegans metabolic research.

Biochemical and High Throughput Microscopic Assessment of Fat Mass in Caenorhabditis Elegans

We present robust biochemical and microscopic methods for studying Caenorhabditis elegans lipid stores. A rapid, simple, fixing-staining procedure for fluorescent lipid droplet imaging leverages the spectral properties of the lipophilic dye Nile red. We then present biochemical measurement of triglycerides and phospholipids using solid phase extraction and gas chromatography-mass spectrometry.

الكيمياء الحيوية والعليا تقييم مجهرية مرت من كتلة الدهون في<em&gt; Caenorhabditis ايليجانس</em

The nematode C. elegans has emerged as an important  model for the study of conserved genetic pathways regulating fat metabolism as  it relates to human ...

Biology

Palatable Western-style Cafeteria Diet as a Reliable Method for Modeling Diet-induced Obesity in Rodents

Obesity is rapidly increasing in incidence in developed and developing countries and is known to induce or exacerbate many diseases.&#160;The health burden of obesity and its comorbid conditions highlight the need for better understanding of its pathogenesis, yet ethical constraints limit studies in humans. To this end externally valid models of obesity in laboratory animals are essential for the understanding of being overweight and obesity.&#160;While many species have been used to model the range of changes that accompany obesity in humans, rodents are most commonly used. Our laboratory has developed a western-style cafeteria diet that consistently leads to considerable weight gain and markers of metabolic disease in rodents. The diet exposes rodents to a variety of highly palatable foods to induce hyperphagia, modeling the modern western food environment. This diet rapidly induces weight gain and body fat accumulation in rats allowing for the study of effects of overeating and obesity. While the cafeteria diet may not provide the same control over macronutrient and micronutrient profile as purified high-fat or high-fat, high-sugar diets, the cafeteria diet typically induces a more severe metabolic phenotype than that observed with purified diets and is more in line with metabolic disturbances observed in the overweight and obese human population.

This protocol describes the use of a highly palatable, western-style cafeteria diet to model overeating and obesity in rodents. Here, we provide a detailed outline of food selection, preparation and measurement, and explain methodological factors that assist in generating a robust and reproducible phenotype.

مستساغا الغربية علي غرار النظام الغذائي كافتيريا كطريقه موثوق بها لنمذجة السمنة التي يسببها النظام الغذائي في القوارض

Obesity is rapidly increasing in incidence in developed and developing countries and is known to induce or exacerbate many diseases.&#160;The health ...

Assessing Whole-Body Lipid-Handling Capacity in Mice

Assessing lipid metabolism is a cornerstone of evaluating metabolic function, and it is considered essential for in vivo metabolism studies. Lipids are a class of many different molecules with many pathways involved in their synthesis and metabolism. A starting point for evaluating lipid hemostasis for nutrition and obesity research is needed. This paper describes three easy and accessible methods that require little expertise or practice to master, and that can be adapted by most labs to screen for lipid-metabolism abnormalities in mice. These methods are (1) measuring several fasting serum lipid molecules using commercial kits (2) assaying for dietary lipid-handling capability through an oral intralipid tolerance test, and (3) evaluating the response to a pharmaceutical compound, CL 316,243, in mice. Together, these methods will provide a high-level overview of lipid handling capability in mice.

This paper provides three easy and accessible assays for assessing lipid metabolism in mice.

تقييم قدرة معالجة الدهون في الجسم كله في الفئران

Assessing lipid metabolism is a cornerstone of evaluating metabolic function, and it is considered essential for in vivo metabolism studies. Lipids are a ...

Identification and Dissection of Diverse Mouse Adipose Depots

Adipose tissues are complex organs with a wide array of functions, including storage and mobilization of energy in response to local and global needs, uncoupling of metabolism to generate heat, and secretion of adipokines to regulate whole-body homeostasis and immune responses. Emerging research is identifying important regional differences in the developmental, molecular, and functional profiles of adipocytes located in discrete depots throughout the body. Different properties of the depots are medically relevant since metabolic diseases often demonstrate depot-specific effects. This protocol will provide investigators with a detailed anatomic atlas and dissection guide for the reproducible and accurate identification and excision of diverse mouse adipose tissues. Standardized dissection of discrete adipose depots will allow detailed comparisons of their molecular and metabolic characteristics and contributions to local and systemic pathologic states under various nutritional and environmental conditions.

Adipocytes exist in discrete depots and have diverse roles within their unique microenvironments. As regional differences in adipocyte character and function are uncovered, standardized identification and isolation of depots is crucial for advancement of the field. Herein, we present a detailed protocol for the excision of various mouse adipose depots.

تحديد وتشريح مستودعات الماوس المتنوعة

Adipose tissues are complex organs with a wide array of functions, including storage and mobilization of energy in response to local and global needs, ...

Assessment of the Metabolic Effects of Isocaloric 2:1 Intermittent Fasting in Mice

Intermittent fasting (IF), a dietary intervention involving periodic energy restriction, has been considered to provide numerous benefits and counteract metabolic abnormalities. So far, different types of IF models with varying durations of fasting and feeding periods have been documented. However, interpreting the outcomes is challenging, as many of these models involve multifactorial contributions from both time- and calorie-restriction strategies. For example, the alternate day fasting model, often used as a rodent IF regimen, can result in underfeeding, suggesting that health benefits from this intervention are likely mediated via both caloric restriction and fasting-refeeding cycles. Recently, it has been successfully demonstrated that 2:1 IF, comprising 1 day of fasting followed by 2 days of feeding, can provide protection against diet-induced obesity and metabolic improvements without a reduction in overall caloric intake. Presented here is a protocol of this isocaloric 2:1 IF intervention in mice. Also described is a pair-feeding (PF) protocol required to examine a mouse model with altered eating behaviors, such as hyperphagia. Using the 2:1 IF regimen, it is demonstrated that isocaloric IF leads to reduced body weight gain, improved glucose homeostasis, and elevated energy expenditure. Thus, this regimen may be useful to investigate the health impacts of IF on various disease conditions.

The current article describes a detailed protocol for isocaloric 2:1 intermittent fasting to protect and treat against obesity and impaired glucose metabolism in wild-type and ob/ob mice.

تقييم الآثار الايضيه من Isocaloric 2:1 الصيام المتقطع في الفئران

Intermittent fasting (IF), a dietary intervention involving periodic energy restriction, has been considered to provide numerous benefits and counteract ...

تكوين الجسم والتحليل الأيضي حبس في الفئران بنك الاحتياطي الفيدرالي الدهون عالية

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