Brain death significantly reduces isolated pancreatic islet yields and functionality in vitro and in vivo after transplantation in rats.
Although approximately 1 million islets exist in the adult human pancreas, current pancreas preservation and islet isolation techniques recover <50%. Presently, cadaveric donors remain the sole source of pancreatic tissue for transplantation. Brain death is characterized by activation of proinflammatory cytokines and organ injury during preservation and reperfusion. In this study, we assessed the effects of brain death on islet isolation yields and functionality. Brain death was induced in male 250- to 350-g Lewis rats by inflation of a Fogarty catheter placed intracranially. The rats were mechanically ventilated for 2, 4, and 6 h before removal of the pancreas (n = 6). In controls, the catheter was not inflated (n = 6). Shortly after brain death induction, a significant increase in serum tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6 was demonstrated in a time-dependent manner. Upregulation of TNF-alpha, IL-1beta, and IL-6 mRNA was noted in the pancreas. Brain death donors presented lower insulin release after glucose stimulation assessed by in situ perfusion of the pancreas. Islet recovery was reduced in brain death donors compared with controls (at 6 h 602.3 +/- 233.4 vs. 1,792.5 +/- 325.4 islet equivalents, respectively; P < 0.05). Islet viability assessed in dissociated islet cells and in intact cultured islets was reduced in islets recovered from brain death donors, an effect associated with higher nuclear activities of NF-kappaB p50, c-Jun, and ATF-2. Islet functionality evaluated in vitro by static incubation and in vivo after intraportal transplantation in syngeneic streptozotocin-induced diabetic rats was significantly reduced in preparations obtained from brain death donors. In conclusion, brain death significantly reduced islet yields and functionality. These observations may lead to strategies to reduce the effects of brain death on pancreatic islets and improve the results in clinical transplantation.
Contreras
Juan L
JL
Division of Transplantation, University of Alabama at Birmingham, Birmingham, Alabama, USA. juan.contreras@ccc.uab.edu
Eckstein
Christopher
C
Smyth
Cheryl A
CA
Sellers
Marty T
MT
Vilatoba
Mario
M
Bilbao
Guadalupe
G
Rahemtulla
Firoz G
FG
Young
Carlton J
CJ
Thompson
J Anthony
JA
Chaudry
Irshad H
IH
Eckhoff
Devin E
DE
D000818:Animals; D017209:Apoptosis; D001926:Brain Death / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000601:surgery*; D006085:Graft Survival; D066298:In Vitro Techniques; D018836:Inflammation Mediators / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D020127:Recovery of Function; D014019:Tissue Donors; D014022:Tissue Survival; D014157:Transcription Factors / Q000378:metabolism
D016207:Cytokines; D018836:Inflammation Mediators; D007328:Insulin; D014157:Transcription Factors