The purpose of this study was to examine the effect of incubation temperatu
re on the structural integrity of the islet during culture. Islets were iso
lated from the pancreas of the Syrian golden hamster and cultured in a coll
agen gel for less than or equal to 12 days at 24 degrees C or 37 degrees C.
At 24 degrees C, cells in the islet periphery died, leading to a complete
disintegration of the mantle region in 37.4 +/- 5.6% of the islets. In comp
arison, at 37 degrees C, few islets exhibited mantle disintegration (p < 0.
001). Insulin immunoreactivity was distributed nonhomogeneously in islets a
t 24 degrees C, and the intensity of the staining, by using a semiquantitat
ive scale (0-3), was +1. Islets cultured at 37 degrees C had a normal homog
eneous distribution of insulin immunoreactivity with a score of +3. As the
pancreas is a complex gland composed of different cell types, and cell-cell
interactions are known to be important in the maintenance of cell survival
, additional experiments were repeated to include the coculture of islets w
ith duct epithelial cells. The proportion of islets that developed mantle d
isintegration was now reduced to 2.5 +/- 0.3% (p < 0.001), comparable to th
at seen at 37 degrees C. Similar results were obtained for islets cultured
in the presence of duct-conditioned medium (DCM). Together with the preserv
ation of the islet mantle, islets cultured in the presence of duct epitheli
al cells or DCM had a normal homogeneous distribution of insulin immunoreac
tivity, with a staining intensity of +3. We conclude that incubation temper
ature has a profound effect on the structural integrity of islets, and that
the detrimental effects of low-temperature culture can be mitigated by coc
ulture of islets with secretory products derived from pancreatic ductal cel
ls. These data provide evidence for a trophic relation between pancreatic i
slets and ductal epithelium.