We thank FAPESP (Funda&#231;&#227;o de Amparo &#224; Pesquisa do Estado de S&#227;o Paulo) for granting financial support.

Animal experiments complied with the Ethics Committee for Experimental Animals Use and Care of the Faculty of Medicine of the University of S&#227;o Paulo (protocol number 112/16).
1. Animal grouping
<ol>
	<li>Randomly assign twelve male Sprague Dawley rats (250-300 g) to one of three experimental groups (n=4) to analyze and compare the effects associated with the animal models.</li>
	<li>Assign animals to hemorrhagic shock group (HS, n=4): animals subjected to vasc...

In recent years, the increasing number of diagnoses of brain death has led to it becoming the largest provider of organs and tissues intended for transplantation. This growth, however, has been accompanied by an incredible increase in donations after circulatory death. Despite its multifactorial nature, most of the triggering mechanisms of the causes of death begin after or accompany trauma with extensive loss of blood content4,18.
In ...

Clinical relevance 
Organ transplantation is a well-established therapeutic option for several serious pathologies. In recent years, many advances have been achieved in the clinical and experimental fields of organ transplantation, such as greater knowledge of the pathophysiology of primary graft dysfunction (PGD) and advances in the areas of intensive care, immunology, and pharmacology1,2,3. Despite the achievements and improvements in the quality of the related surgical and pharmacological procedures, the relationship between the number of available organs and the number of recipients on the waiting list remains one of the main challenges2,4. In this regard, the scientific literature has proposed animal models for studying therapies that can be applied to organ donors to treat and/or preserve the organs until the time of transplantation5,6,7,8.
By mimicking the different events observed in clinical practice, animal models allow the study of the associated pathological mechanisms and their respective therapeutic approaches. The experimental induction of these events, in most isolated cases, has generated experimental models of organ and tissue donation that are widely investigated in the scientific literature on organ transplantation6,7,8,9. These studies employ different methodological strategies, such as those inducing brain death (BD), hemorrhagic shock (HS), and circulatory death (CD), since these events are associated with different deleterious processes that compromise the functionality of the donated organs and tissues.
Brain death (BD) 
BD is associated with a series of events that lead to the progressive deterioration of different systems. It usually occurs when an acute or gradual increase in intracranial pressure (ICP) happens due to brain trauma or hemorrhage. This increase in ICP promotes an increase in blood pressure in an attempt to maintain a stable cerebral blood flow in a process known as Cushing&#39;s reflex10,11. These acute changes can result in cardiovascular, endocrine, and neurological dysfunctions that compromise the quantity and quality of the donated organs, in addition to impacting post-transplantation morbidity and mortality10,11,12,13.
Hemorrhagic shock (HS) 
HS, in turn, is often associated with organ donors, as most of them are victims of trauma with significant loss of blood volume. Some organs, such as the lungs and heart, are particularly vulnerable to HS due to hypovolemia and consequent tissue hypoperfusion14. HS induces lung injury through increased capillary permeability, edema, and infiltration of inflammatory cells, mechanisms that together compromise gas exchange and lead to progressive organ deterioration, consequently derailing the donation process6,14.
Circulatory death (CD) 
The use of post-CD donation has been growing exponentially in major world centers, thus contributing to the increase in the number of collected organs. Organs recovered from post-CD donors are vulnerable to the effects of warm ischemia, which occurs after an interval of low (agonic phase) or no blood supply (asystolic phase)8,15. Hypoperfusion or the absence of blood flow will lead to tissue hypoxia associated with the abrupt loss of ATP and the accumulation of metabolic toxins in tissues15. Despite its current use for transplantation in clinical practice, many doubts remain about the impact of the use of these organs on the quality of the post-transplant graft and on patient survival15. Thus, the use of experimental models for a better understanding of the etiological factors associated with CD is also growing8,15,16,17.
Experimental models 
There are various experimental organ donation models (BD, HS, and CD). However, studies often focus on only one strategy at a time. There is a noticeable gap in studies that combine or compare two or more strategies. These models are very useful in the development of therapies that seek to increase the number of donations and consequently decrease the waiting list of potential recipients. The animal species used for this purpose vary from study to study, with porcine models being more commonly selected when the objective is a more direct translation with human morpho physiology and less technical difficulty in the surgical procedure due to the size of the animal. Despite the benefits, logistical difficulties and high costs are associated with the porcine model. On the other hand, the low cost and possibility of biological manipulation favor the use of rodent models, allowing the researcher to start from a reliable model to reproduce and treat lesions, as well as to integrate the knowledge acquired in the field of organ transplantation.
Here, we present a rodent model of brain death, circulatory death, and hemorrhagic shock donation. We describe inflammatory processes and pathological conditions associated with each of these models.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>14-gauge angiocath</td>
			<td>DB</td>
			<td>38186714</td>
			<td>Orotracheal intubation</td>
		</tr>
		<tr>
			<td>2.0-silk</td>
			<td>Brasuture</td>
			<td>AA553</td>
			<td>Tracheal tube fixation</td>
		</tr>
		<tr>
			<td>24-gauge angiocath</td>
			<td>DB</td>
			<td>38181214</td>
			<td>Arterial and venous access</td>
		</tr>
		<tr>
			<td>4.0-silk</td>
			<td>Brasuture</td>
			<td>AA551</td>
			<td>Fixation of arterial and venous cannulas</td>
		</tr>
		<tr>
			<td>Alcoholic chlorhexidine digluconate solution (2%).</td>
			<td>Vic Pharma</td>
			<td>Y/N</td>
			<td>Asepsis</td>
		</tr>
		<tr>
			<td>Trichotomy apparatus</td>
			<td>Oster</td>
			<td>Y/N</td>
			<td>Clipping device</td>
		</tr>
		<tr>
			<td>Precision balance</td>
			<td>Shimadzu</td>
			<td>D314800051</td>
			<td>Analysis of the wet/dry weight ratio</td>
		</tr>
		<tr>
			<td>Barbiturate (Thiopental)</td>
			<td>Crist&#225;lia</td>
			<td>18080003</td>
			<td>DC induction</td>
		</tr>
		<tr>
			<td>Balloon catheter (Fogarty-4F)</td>
			<td>Edwards Life Since</td>
			<td>120804</td>
			<td>BD induction</td>
		</tr>
		<tr>
			<td>Neonatal extender</td>
			<td>Embramed</td>
			<td>497267</td>
			<td>Used as catheters with the aid of the 24 G angiocath</td>
		</tr>
		<tr>
			<td>FlexiVent</td>
			<td>Scireq</td>
			<td>1142254</td>
			<td>Analysis of ventilatory parameters</td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>Blau Farmaceutica SA</td>
			<td>7000982-06</td>
			<td>Anticoagulant</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Crist&#225;lia</td>
			<td>10,29,80,130</td>
			<td>Inhalation anesthesia</td>
		</tr>
		<tr>
			<td>Micropipette (1000 &#181;L)</td>
			<td>Eppendorf</td>
			<td>347765Z</td>
			<td>Handling of small- volume liquids</td>
		</tr>
		<tr>
			<td>Micropipette (20 &#181;L)</td>
			<td>Eppendorf</td>
			<td>H19385F</td>
			<td>Handling of small- volume liquids</td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Zeiss</td>
			<td>1601004545</td>
			<td>Assistance in the visualization of structures for the surgical procedure</td>
		</tr>
		<tr>
			<td>Multiparameter monitor</td>
			<td>Dixtal</td>
			<td>101503775</td>
			<td>MAP registration</td>
		</tr>
		<tr>
			<td>Motorized drill</td>
			<td>Midetronic</td>
			<td>MCA0439</td>
			<td>Used to drill a 1 mm caliber borehole</td>
		</tr>
		<tr>
			<td>Neubauer chamber</td>
			<td>Kasvi</td>
			<td>D15-BL</td>
			<td>Cell count</td>
		</tr>
		<tr>
			<td>Pediatric laryngoscope</td>
			<td>Oxygel</td>
			<td>Y/N</td>
			<td>Assistance during tracheal intubation</td>
		</tr>
		<tr>
			<td>Syringe (3 mL)</td>
			<td>SR</td>
			<td>3330N4</td>
			<td>Hydration and exsanguination during HS protocol</td>
		</tr>
		<tr>
			<td>Pressure transducer</td>
			<td>Edwards Life Since</td>
			<td>P23XL</td>
			<td>MAP registration</td>
		</tr>
		<tr>
			<td>Metallic tracheal tube</td>
			<td>Biomedical</td>
			<td>006316/12</td>
			<td>Rigid cannula for analysis with the FlexiVent ventilator</td>
		</tr>
		<tr>
			<td>Isoflurane vaporizer</td>
			<td>Harvard Bioscience</td>
			<td>1,02,698</td>
			<td>Anesthesia system</td>
		</tr>
		<tr>
			<td>Mechanical ventilator for small animals (683)</td>
			<td>Harvard Apparatus</td>
			<td>MA1 55-0000</td>
			<td>Mechanical ventilation</td>
		</tr>
		<tr>
			<td>xMap methodology</td>
			<td>Millipore</td>
			<td>RECYTMAG-65K-04</td>
			<td>Analysis of inflammatory markers</td>
		</tr>
	</tbody>
</table>

study of experimental organ donation models for lung transplantation

Experimental models are important tools for understanding the etiological phenomena involved in various pathophysiological events. In this context, different animal models are used to study the elements triggering the pathophysiology of primary graft dysfunction after transplantation to evaluate potential treatments. Currently, we can divide experimental donation models into two large groups: donation after brain death and donation after circulatory arrest. In addition, the deleterious effects associated with hemorrhagic shock should be considered when considering animal models of organ donation. Here, we describe the establishment of three different lung donation models (post-brain death donation, post-circulatory death donation, and post-hemorrhagic shock donation) and compare the inflammatory processes and pathological disorders associated with these events. The objective is to provide the scientific community with reliable animal models of lung donation for studying the associated pathological mechanisms and searching for new therapeutic targets to optimize the number of viable grafts for transplantation.

Mean arterial pressure (MAP) 
To determine the hemodynamic repercussions of BD and HS, MAP was evaluated across the 360 min of the protocol. The baseline measurement was collected after skin removal and skull drilling and before blood aliquot collection for animals subjected to BD or HS, respectively. Prior to BD and HS induction, the baseline MAP of the two groups was similar (BD: 110.5 &#177; 6.1 vs. HS: 105.8 &#177; 2.3 mmHg; p=0.5; two-way ANOVA). After catheter insufflation, the BD group experi...

Watch this Scientific Journal Video about Study of Experimental Organ Donation Models for Lung Transplantation at JoVE.com

Study of Experimental Organ Donation Models for Lung Transplantation

The present study shows the establishment of three different lung donation models (post-brain death donation, post-circulatory death donation, and post-hemorrhagic shock donation). It compares the inflammatory processes and pathological disorders associated with these events.

Experimental models are important tools for understanding the etiological phenomena involved in various pathophysiological events. In this context, ...

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Medicine

616 vistas.  Universidade de São Paulo. Los modelos experimentales de donación de órganos generalmente imitan situaciones aisladas de lesión tisular relacionadas con el proceso de muerte y/o eventos relacionados con la preservación e implantación del órgano. Estos modelos son muy útiles en el desarrollo de terapias que buscan aumentar el número de donaciones, y en consecuencia disminuir la lista de ponderación de potenciales receptores. En consecuencia, se ha vuelto importante desarrollar diferentes modelos, como los que i...