Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
  Users Online: 165 Home Print this page Email this page Small font sizeDefault font sizeIncrease font size  

 Table of Contents  
Year : 2015  |  Volume : 5  |  Issue : 3  |  Page : 195-199  

Apelin protect against multiple organ injury following hemorrhagic shock and decrease the inflammatory response

1 Department of Physiology, College of Medicine, King Saud University, Riyadh 11461, Saudi Arabia
2 Department of Pathology, College of Medicine, King Saud University, Riyadh 11461, Saudi Arabia

Date of Submission26-Nov-2014
Date of Acceptance09-Jul-2015
Date of Web Publication15-Sep-2015

Correspondence Address:
Mona Soliman
Department of Physiology, College of Medicine, King Khalid University Hospital, P.O. Box 2925 (29), Riyadh 11461
Saudi Arabia
Login to access the Email id

Source of Support: This work was supported by a grant from the National Plan for Science, Technology and Innovation (12-MED2525-02) at King Saud University, Riyadh, Saudi Arabia., Conflict of Interest: There are no conflicts of interest.

DOI: 10.4103/2229-516X.165377

Rights and Permissions

Introduction: Hemorrhagic shock (HS) result in multiple organ injury and inflammatory response that lead to death. The exact mechanism is not clear. Apelin is an endogenous ligand of orphan G-protein coupled receptor APJ. Apelin has anti-inflammatory effects on the release of inflammatory mediators. Objectives: To examine the protective effects of apelin against multiple organ injury and the possible involvement of inflammatory pathways. Methodology: Male Sprague-Dawley rats (300–350 g) were subjected to hemorrhage over 60 min to reach a mean arterial blood pressure of 40 mmHg. Then, rats were treated or not with 1 mL of 10 nm/L apelin-13 intraarterially resuscitation was performed in vivo by the reinfusion of the shed blood for 30 min to restore normotension. Blood samples were collected for measurement of tumor necrosis factor (TNF) using ELISA (R and D systems). Biopsies were obtained from organs for light microscopic examination. Results: HS rats showed significant increase the levels of TNF. Apelin significantly lowered the production of TNF-α. Histological examination of hemorrhagic shocked untreated rats revealed structural damage. Less histological damage was observed in the organs of treated rats. Apelin-treatment decreased the number of inflammatory cells and mitochondrial swollen in cells. Conclusion: Treatment with apelin before resuscitation protects against multiple organ injury in HS by attenuation the inflammatory response and might be a therapeutic target for HS.

Keywords: Apelin, hemorrhage, rat, shock, structure, tumor necrosis factor

How to cite this article:
Soliman M, Arafah M. Apelin protect against multiple organ injury following hemorrhagic shock and decrease the inflammatory response. Int J App Basic Med Res 2015;5:195-9

How to cite this URL:
Soliman M, Arafah M. Apelin protect against multiple organ injury following hemorrhagic shock and decrease the inflammatory response. Int J App Basic Med Res [serial online] 2015 [cited 2021 Jul 28];5:195-9. Available from: https://www.ijabmr.org/text.asp?2015/5/3/195/165377

   Introduction Top

Hemorrhagic shock (HS) and resuscitation is known to result in multiple organ injury and activate inflammatory responses that can lead to death.[1] Despite the advances in critical care, still hemorrhage is a leading cause of death following trauma.[2] HS, trauma, and multiple organ dysfunction remain a challenge in the treatment of trauma patients. The exact mechanism (s) is not clear. However, there are several mechanisms involved in the pathogenesis of multiple organ injury and failure following hemorrhagic shock. One known mechanism is the activation of inflammatory pathways.[3],[4] Hemorrhagic shock and resuscitation activate an inflammatory process that can increase the risk of death after trauma,[5] HS activate the immune system that result in the activation of monocytes and leukocytes.[5] The immune cells hereby will produce proinflammatory markers as well as reactive oxygen species. The inflammatory response will trigger a series of reactions that lead to tissue injury.[6],[7] Activation of the inflammatory pathways is associated with multiple organ injury, dysfunction, and failure.[8],[9] Tumor necrosis factor (TNF) is one of the most characteristic inflammatory factors contributing to organ injury following HS.[10],[11],[12]

Apelin is a novel endogenous ligand for the G-protein-coupled receptor APJ. Apelin receptors are present in the central nervous system and the peripheral tissues, in the heart, lung, kidney, and endothelial cells [13] and endothelial cells.[14] Apelin has been shown to be involved in the regulation of cardiovascular function, angiogenesis, fluid homeostasis, and energy metabolic. It is becoming apparent that apelin may play a pathophysiological role in many of the regulatory systems.[15] Progress has been made in recent years in clarifying the significance of apelin, much remains to be discovered. Apelin was shown to have anti-inflammatory effects on inflammatory mediator release.[16],[17]

This study investigated the protective effects of apelin administration before resuscitation of hemorrhagic in preventing multiple organ injury. Furthermore, we analyze the possible mechanism of protection by analyzing the potential of apelin to lower systemic TNF production following resuscitation.

   Methodology Top

Animal preparation

The study was approved by the Ethical Committee at King Abdul-Aziz City for Science and Technology. Male Sprague-Dawley rats were injected intra-peritonealy (i.p.) with heparin sodium 2000 IU 15 min prior to anesthesia. The rats were then anesthetized using urethane 125 mg/kg i.p. The left carotid artery was cannulated using polyethylene tubing size 60, and was connected to an in-line pressure transducer for continuous blood pressure monitoring. Animals were allowed to stabilize for a period of 30 min. The animals were assigned randomly to 33 experimental groups (n = 6 per group): (1) Normotensive rats (N), (2) HS rats and (3) hemorrhagic shock rats treated with apelin-13 (HS-AP).

Hemorrhage and resuscitation

As previously described,[18],[19],[20],[21] rats were hemorrhaged using a reservoir (a 10 mL syringe) that is connected to the arterial (carotid artery) three-way stopcocks. Opening the stopcock and aspirating gently and gradually with the syringe will induce hemorrhage. Blood was aspirated at a rate of 1 mL/min. Blood was continuously withdrawn or re-infused to the animal to maintain a mean arterial pressure of approximately 40 mmHg. The same surgical procedures were performed as for the sham hemorrhage group except rats will not be hemorrhaged.

After 60 min hemorrhage period, hearts were resuscitated in vivo, by reinfusion of the shed blood to restore normotension and blood pressure were monitored for 30 min. Rats were either treated or not with an intra-arterial injection of apelin-13.

Experimental groups

Three experimental groups (n = 6) were assigned for the study:

  • Normotensive rats (N) - rats will undergo the same surgical preparation and were monitored for continuous blood pressure measurements for the experimental period 120 min
  • HS rats - after 30 min stabilization period, rats were hemorrhaged to 40 mmHg for 60 min. Rats were then resuscitated and monitored for 30 min
  • Effect of apelin-13 during HS (HS-AP) - after 30 min stabilization period, rats were hemorrhaged to 40 mmHg for 60 min. One milliliter of 10 nm/L apelin-13 was injected intra-arterially. Rats were then resuscitated and monitored for 30 min.

Light microscopy

To perform a histological examination of multiple organs, rat heart, intestine, kidney, and liver were harvested and stored in 10% formalin solution (n = 6 in each group). We obtained 2 transverse sections per organ for histological examination and sections were stained with hematoxylin and eosin (H and E) stain. The areas affected by HS and resuscitation consisting of inflammatory cells, necrosis, and hemorrhage, were determined in the H and E staining. All data were analyzed in a blind fashion.

Tumor necrosis factor measurements

Blood (0.5 mL) was collected from the left carotid artery cannula before hemorrhage, before resuscitation and 30 min after resuscitation and centrifuged at 2500 g for 10 min and plasma was stored at −80°C until analysis for TNF-α measurement. Serum samples were analyzed by ELISA.

Statistical analysis

Data were initially analyzed with Bartlett's test for homogeneity. Data found not to be homogeneous were transformed and reanalyzed. Data were analyzed with multivariate analysis of variance. Means were analyzed using Duncan's test and were considered significant when yielding a P ≤ 0.05. Data were expressed as means ± standard deviation.

   Results Top

The animals were subjected to HS to lower the mean arterial blood pressure to the desired level of hypotension (35–40 mmHg). The total volume of blood withdrawn was 15 ± 1.1 mL/kg body weight. There was no significant difference in the amount of blood withdrawn among the groups of animals subjected to HS.

Apelin decreased the inflammatory response to hemorrhagic shock

As observed in [Figure 1], HS caused a significant increase in the serum levels of TNF-α when compared to normotensive group (P < 0.05). Treatment with apelin before resuscitation following HS significantly lowered the levels of TNF-α [Figure 1].
Figure 1: Hemorrhage increased tumor necrosis factor-α levels. *P < 0.05 versus sham group (n = 6 per group), and •P < 0.05 versus hemorrhage group (n = 6 per group)

Click here to view

Apelin decrease organ injury after hemorrhagic shock

HS and resuscitation caused multiple organ injury [Figure 2]. Heart sections in the H and E-stain showed areas of hemorrhage, coagulation necrosis with diffuse edema and neutrophil infiltration [Figure 2]a, [Figure 2]b, [Figure 2]c. Blood vessels in the heart sections showed swollen endothelium with neutrophil infiltration [Figure 2]d and [Figure 2]e.
Figure 2: Light micrographs of multiple organs from hemorrhagic shocked rats. (a-c) Heart section showing inflammatory cell infiltration around blood vessels and edema (H and E, ×100, ×400 and × 400). (d and e) Endothelium of blood vessel in the heart, showing swollen endothelium with neutrophil infiltration (H and E, ×400 and × 600)

Click here to view

Sections from multiple organs of treated animals before resuscitation of HS showed normal tissue with no evidence of inflammation and tissue injury. [Figure 3] shows tissues obtained from multiple organs from animals treated with apelin before resuscitation following HS. The inflammatory infiltration and the increase in the number of neutrophils were prevented by treatment with apelin.
Figure 3: Light micrographs of multiple organs from hemorrhagic shocked rats treated with apelin showing normal tissue. (a) Heart section (H and E, ×200). (b and c) Endothelium (H and E, ×400 and × 600). (d and e) Intestinal section (H and E, ×100 and × 400). (f and g) Liver section (H and E, ×400 and × 200). (h) Kidney section (H and E, ×600)

Click here to view

   Discussion Top

Despite the advances in critical care, resuscitation strategies fail to prevent deleterious inflammatory responses. Resuscitation can cause systemic inflammatory responses that can lead to multiple organ injury, dysfunction, and death.[8] This study showed that HS and resuscitation are associated with multiple organ injury and activation of inflammatory responses. The study showed that apelin may provide a therapeutic potential to resuscitation following HS. Animals treated with apelin showed no evidence of organ injury after resuscitation. One explanation is by lowering the inflammatory response to HS and resuscitation.

The results from the present study are in agreement with previous reports that showed that resuscitation following HS results in multiple organ injury and dysfunction.[4]

Apelin has been shown to have anti-inflammatory effects.[22] We speculated that apelin could protect against postresuscitation organ injury by attenuating inflammatory responses. The present study showed that apelin decreased the inflammatory response to shock and protected against postresuscitation organ injury.

However, the protective mechanism of apelin against multiple organ injury is not fully understood. Our previous study showed that apelin protect against myocardial dysfunction following in vivo and ex vivo resuscitation following HS.[23] Previous studies have shown that apelin has a cardioprotective effect.[24],[25] Apelin is an endogenous substance that may involve activation of phosphatidalipase C, protein kinase C, and sacrolemmal sodium hydrogen exchange, and sodium-calcium exchange.[26]

The mechanisms of the apelin protective effects may be from enhancing the activity of sodium hydrogen exchange with consequent intracellular alkalization.[27]

However, the activation of the inflammatory pathways is the key process in organ dysfunction following HS and the production of inflammatory markers such as TNF.[8],[25]

The results of the present study and other previous studies on apelin had led to speculation that apelin could be a future target for therapeutic strategies following HS and resuscitation.

   Conclusion Top

Apelin protect against multiple organ injury following resuscitation of HS by attenuation of the inflammatory response.

Apelin may attenuate the inflammatory.


This work was supported by a grant from the National Plan for Science, Technology and Innovation (12-MED2525-02) at King Saud University, Riyadh, Saudi Arabia.

Financial support and sponsorship

This work was supported by a grant from the National Plan for Science, Technology and Innovation (12-MED2525-02) at King Saud University, Riyadh, Saudi Arabia.

Conflicts of interest

There are no conflicts of interest.

   References Top

Kholmukhamedov A, Czerny C, Hu J, Schwartz J, Zhong Z, Lemasters JJ. Minocycline and doxycycline, but not tetracycline, mitigate liver and kidney injury after hemorrhagic shock/resuscitation. Shock 2014;42:256-63.  Back to cited text no. 1
Mannucci PM, Levi M. Prevention and treatment of major blood loss. N Engl J Med 2007;356:2301-11.  Back to cited text no. 2
Yu TC, Yang FL, Hsu BG, Wu WT, Chen SC, Lee RP, et al. Deleterious effects of aggressive rapid crystalloid resuscitation on treatment of hyperinflammatory response and lung injury induced by hemorrhage in aging rats. J Surg Res 2014;187:587-95.  Back to cited text no. 3
Levy G, Fishman JE, Xu D, Chandler BT, Feketova E, Dong W, et al. Parasympathetic stimulation via the vagus nerve prevents systemic organ dysfunction by abrogating gut injury and lymph toxicity in trauma and hemorrhagic shock. Shock 2013;39:39-44.  Back to cited text no. 4
Wetzel G, Relja B, Klarner A, Henrich D, Dehne N, Brühne B, et al. Myeloid knockout of HIF-1 α does not markedly affect hemorrhage/resuscitation-induced inflammation and hepatic injury. Mediators Inflamm 2014;2014:930419.  Back to cited text no. 5
Redl H, Gasser H, Schlag G, Marzi I. Involvement of oxygen radicals in shock related cell injury. Br Med Bull 1993;49:556-65.  Back to cited text no. 6
Passos JF, Saretzki G, von Zglinicki T. DNA damage in telomeres and mitochondria during cellular senescence: Is there a connection? Nucleic Acids Res 2007;35:7505-13.  Back to cited text no. 7
Cai B, Deitch EA, Grande D, Ulloa L. Anti-inflammatory resuscitation improves survival in hemorrhage with trauma. J Trauma 2009;66:1632-9.  Back to cited text no. 8
Rushing GD, Britt LD. Reperfusion injury after hemorrhage: A collective review. Ann Surg 2008;247:929-37.  Back to cited text no. 9
Tracey KJ, Cerami A. Tumor necrosis factor, other cytokines and disease. Annu Rev Cell Biol 1993;9:317-43.  Back to cited text no. 10
Tracey KJ, Cerami A. Tumor necrosis factor: A pleiotropic cytokine and therapeutic target. Annu Rev Med 1994;45:491-503.  Back to cited text no. 11
Ulloa L, Tracey KJ. The "cytokine profile": A code for sepsis. Trends Mol Med 2005;11:56-63.  Back to cited text no. 12
Medhurst AD, Jennings CA, Robbins MJ, Davis RP, Ellis C, Winborn KY, et al. Pharmacological and immunohistochemical characterization of the APJ receptor and its endogenous ligand apelin. J Neurochem 2003;84:1162-72.  Back to cited text no. 13
Kleinz MJ, Davenport AP. Immunocytochemical localization of the endogenous vasoactive peptide apelin to human vascular and endocardial endothelial cells. Regul Pept 2004;118:119-25.  Back to cited text no. 14
O'Carroll AM, Lolait SJ, Harris LE, Pope GR. The apelin receptor APJ: Journey from an orphan to a multifaceted regulator of homeostasis. J Endocrinol 2013;219:R13-35.  Back to cited text no. 15
Esposito V, De Falco M, De Luca L, Acanfora F, Onori N, Loiacono L, et al. Immunohistochemical study of apelin, the natural ligand of receptor APJ, in a case of AIDS-related cachexia.In Vivo 2002;16:337-40.  Back to cited text no. 16
Horiuchi Y, Fujii T, Kamimura Y, Kawashima K. The endogenous, immunologically active peptide apelin inhibits lymphocytic cholinergic activity during immunological responses. J Neuroimmunol 2003;144:46-52.  Back to cited text no. 17
Soliman M. Dimethyl amiloride, a Na+-H+exchange inhibitor, and its cardioprotective effects in hemorrhagic shock in in vivo resuscitated rats. J Physiol Sci 2009;59:175-80.  Back to cited text no. 18
Soliman M. Inhibition of Na(+)-H(+) exchange before resuscitation following hemorrhagic shock is cardioprotective in rats. J Saudi Heart Assoc 2009;21:159-63.  Back to cited text no. 19
Soliman MM, Arafah MM. Treatment with dipyridamole improves cardiac function and prevent injury in a rat model of hemorrhage. Eur J Pharmacol 2012;678:26-31.  Back to cited text no. 20
Soliman MM. Na(+)-H(+) exchange blockade, using amiloride, decreases the inflammatory response following hemorrhagic shock and resuscitation in rats. Eur J Pharmacol 2011;650:324-7.  Back to cited text no. 21
Pan CS, Teng X, Zhang J, Cai Y, Zhao J, Wu W, et al. Apelin antagonizes myocardial impairment in sepsis. J Card Fail 2010;16:609-17.  Back to cited text no. 22
Soliman M. The effects of apelin on myocardial function after resuscitation of hemorrhagic shock in rats. Arab Gulf Med J 2014;32:122-7.  Back to cited text no. 23
Simpkin JC, Yellon DM, Davidson SM, Lim SY, Wynne AM, Smith CC. Apelin-13 and apelin-36 exhibit direct cardioprotective activity against ischemia-reperfusion injury. Basic Res Cardiol 2007;102:518-28.  Back to cited text no. 24
Kleinz MJ, Baxter GF. Apelin reduces myocardial reperfusion injury independently of PI3K/Akt and P70S6 kinase. Regul Pept 2008;146:271-7.  Back to cited text no. 25
Szokodi I, Tavi P, Földes G, Voutilainen-Myllylä S, Ilves M, Tokola H, et al. Apelin, the novel endogenous ligand of the orphan receptor APJ, regulates cardiac contractility. Circ Res 2002;91:434-40.  Back to cited text no. 26
Farkasfalvi K, Stagg MA, Coppen SR, Siedlecka U, Lee J, Soppa GK, et al. Direct effects of apelin on cardiomyocyte contractility and electrophysiology. Biochem Biophys Res Commun 2007;357:889-95.  Back to cited text no. 27


  [Figure 1], [Figure 2], [Figure 3]

This article has been cited by
1 Reproductive roles of novel adipokines apelin, visfatin, and irisin in farm animals
Borhan Shokrollahi,Jiang-Hua Shang,Hafiz Ishfaq Ahmad,Chun-Yan Yang,Nazila Saadati
Theriogenology. 2021;
[Pubmed] | [DOI]
2 Effect of Omega-3 or Omega-6 Dietary Supplementation on Testicular Steroidogenesis, Adipokine Network, Cytokines, and Oxidative Stress in Adult Male Rats
Amira Moustafa,Yi Fang
Oxidative Medicine and Cellular Longevity. 2021; 2021: 1
[Pubmed] | [DOI]
3 A Potential Role of Apelin-13 against Hepatic Injury and Metabolic Disorders in Preeclampsia Induced by L-NAME
Reham Hamza,Abdel Diab,Mansour Zahra,Mai Attia,Suzan Moursi,Najah Al-Baqami
Coatings. 2021; 11(4): 391
[Pubmed] | [DOI]
4 Fc-Elabela fusion protein attenuates lipopolysaccharide-induced kidney injury in mice
Feng Xu,Huifen Zhou,Man Wu,Hong Zhang,Yixian Zhang,Qingbin Zhao,Robert Brown,Da-Wei Gong,Lining Miao
Bioscience Reports. 2020; 40(9)
[Pubmed] | [DOI]
5 Apelin-13/APJ system attenuates early brain injury via suppression of endoplasmic reticulum stress-associated TXNIP/NLRP3 inflammasome activation and oxidative stress in a AMPK-dependent manner after subarachnoid hemorrhage in rats
Weilin Xu,Tao Li,Liansheng Gao,Jingwei Zheng,Jun Yan,Jianmin Zhang,Anwen Shao
Journal of Neuroinflammation. 2019; 16(1)
[Pubmed] | [DOI]
6 The apelinergic system: a perspective on challenges and opportunities in cardiovascular and metabolic disorders
Eric Marsault,Catherine Llorens-Cortes,Xavier Iturrioz,Hyung J. Chun,Olivier Lesur,Gavin Y. Oudit,Mannix Auger-Messier
Annals of the New York Academy of Sciences. 2019;
[Pubmed] | [DOI]
7 Apelin as a nociceptive processes regulator
Joanna Kujacz,Joanna Mika
BÓL. 2019; 19(3): 1
[Pubmed] | [DOI]
8 Apelin in Reproductive Physiology and Pathology of Different Species: A Critical Review
Patrycja Kurowska,Alix Barbe,Marta Rózycka,Justyna Chmielinska,Joelle Dupont,Agnieszka Rak
International Journal of Endocrinology. 2018; 2018: 1
[Pubmed] | [DOI]
9 Usefulness of the Adipokines as Biomarkers of Ischemic Cardiac Dysfunction
Larisa-Diana Mocan Hognogi,Cerasela-Mihaela Goidescu,Anca-Daniela Farcas
Disease Markers. 2018; 2018: 1
[Pubmed] | [DOI]
10 Inhibition of the apelin/apelin receptor axis decreases cholangiocarcinoma growth
Chad Hall,Laurent Ehrlich,Julie Venter,April OęBrien,Tori White,Tianhao Zhou,Tien Dang,Fanyin Meng,Pietro Invernizzi,Francesca Bernuzzi,Gianfranco Alpini,Terry Lairmore,Shannon Glaser
Cancer Letters. 2017; 386: 179
[Pubmed] | [DOI]
11 Apelin Compared With Dobutamine Exerts Cardioprotection and Extends Survival in a Rat Model of Endotoxin-Induced Myocardial Dysfunction*
Frederic Chagnon,David Coquerel,Dany Salvail,Eric Marsault,Robert Dumaine,Mannix Auger-Messier,Philippe Sarret,Olivier Lesur
Critical Care Medicine. 2017; 45(4): e391
[Pubmed] | [DOI]
12 Serum level of apelin-13 negatively correlated with NT-proBNP in heart failure patients
Cerasela Mihaela Goidescu,Florin Petru Anton,Daniel Corneliu Leucu?a,Petru Adrian Mircea,Lumini?a Animarie Vida-Simiti
Revista Romana de Medicina de Laborator. 2016; 24(4)
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
    Article Figures

 Article Access Statistics
    PDF Downloaded269    
    Comments [Add]    
    Cited by others 12    

Recommend this journal