Impact of porcine islet size on cellular structure and engraftment after transplantation: adult versus young pigs.
OBJECTIVE
To study the impact of porcine islet size on structural properties and cellular engraftment.


METHODS
The endocrine structure and collagen/vascular localization in pig islets were studied before and after enzymatic isolation on the pancreas from 6 young and 6 adult Landrace pigs. Isolated islets from both pig types were transplanted under the kidney capsula of diabetic nude rats to assess cellular engraftment.


RESULTS
In comparison with adult pig pancreata, a significantly greater number of small beta cells (<100 microm) were observed before and after isolation (82% vs. 32%, respectively, P < 0.005) from young pig pancreata. Small islets (<100 microm) showed a peripheral vascular structure, whereas large islets showed a more centralized vascular organization, thereby providing protection during the enzymatic digestion procedure. The islet endocrine structure was not affected by the islet size, but a loss of glucagon cells (-7.9%, P < 0.005) was observed in large isolated islets. The purity of islet preparation was better with pancreata from adult than young donors (86% vs. 64%, respectively, P < 0.05). A lack of engraftment was observed for small islets from young pig donors as compared with large islets from adult donors.


CONCLUSIONS
Large and well-structured islets, mainly found in adult pig pancreata, probably possess a better potential for cellular engraftment due to centralized vascularization and collagen distribution.
Dufrane
D
D
Laboratory of Experimental Surgery, Faculty of Medicine, Université catholique de Louvain, Brussels, Belgium. denis.dufrane@chex.ucl.ac.be
Goebbels
R M
RM
Fdilat
I
I
Guiot
Y
Y
Gianello
P
P
D000367:Age Factors; D000818:Animals; D001706:Biopsy; D002196:Capillaries; D002469:Cell Separation; D048429:Cell Size; D003094:Collagen / Q000378:metabolism; D006085:Graft Survival; D007328:Insulin / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000166:cytology* / Q000378:metabolism; D007515:Islets of Langerhans / Q000098:blood supply / Q000166:cytology; D016381:Islets of Langerhans Transplantation; D051381:Rats; D011917:Rats, Inbred Lew; D034421:Sus scrofa; D014183:Transplantation, Heterologous
D007328:Insulin; D003094:Collagen