[Improvement of massive human islet isolation techniques and the evaluation of isolated human islets].
OBJECTIVE
To obtain massive human pancreatic islets with modified techniques and evaluation of the islets for the clinical allo-transplantation to treat type I and II diabetes.


METHODS
28 consecutive adult human pancreata were isolated with modified automated techniques. Islets were purified using continuous density gradient. The islet yield was counted with international standard known as islet equivalent (IEQ). The function of the isolated islets was evaluated by measuring DNA/insulin ratio, static glucose stimulating test in vitro and transplanting the islets into diabetic nude mice in vivo followed by abdominal glucose tolerance test and C peptide measurement.


RESULTS
The yield of 28 consecutive human pancreata isolations ranged from 5 000 to 1 030 000 IEQs/pancreas with the average of 291 635 IEQs/pancreas. The first 13 isolations yielded 49 123 IEQs/pancreas, 846 IEQs/g and, purity 87% in average. The remained 15 isolations after the modifications yielded 501 813 IEQs/pancreas, 7 003 IEQs/g and purity 89% in average. The results of in vitro SGS showed good response to the different glucose concentration. 34 diabetic nude mice were transplanted under the renal capsule with the freshly isolated islets. 29 out of 34 diabetic mice obtained normoglycemia within 12 hours and the glucose tolerance tests were near normal. Serum C peptide level of transplanted mice is close to that of the control group.


CONCLUSIONS
Massive human islets can be isolated with the modified techniques. Quality assessment of these islets both in vitro and in vivo has indicated that these high quality human islets could be used for the clinical allogeneic islet transplantation.
Song
Zhen-Shun
ZS
Department of Hepato-biliary Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China.
Gu
Ke-Ju
KJ
Zhang
Jian-Guo
JG
D000328:Adult; D000818:Animals; D002469:Cell Separation / Q000379:methods*; D003921:Diabetes Mellitus, Experimental / Q000601:surgery*; D005947:Glucose; D006801:Humans; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D016381:Islets of Langerhans Transplantation; D051379:Mice; D008819:Mice, Nude; D014183:Transplantation, Heterologous
D005947:Glucose