Isolation and Function of Human and Pig Islets

Intercellular Ca2+ waves sustain coordinate insulin secretion in pig islets of Langerhans

“…However, in vitro studies showed a deficit of insulin secretion from pig islets with respect to those obtained from human and rat [12]. Our results clearly indicate that the isolation procedure causes tissue loss revealed by the decrease of islet number during the first two days in culture.…”

“…Pig islets of Langerhans represent a multicellular system which is considered a possible attractive alternative for transplantation in humans [11]. However, in vitro studies showed a deficit of insulin secretion from pig islets with respect to those obtained from human and rat [12]. Our results clearly indicate that the isolation procedure causes tissue loss revealed by the decrease of islet number during the first two days in culture.…”

Glucagon improves insulin secretion from pig islets in vitro

“…Our data show that insulin release from porcine islets is improved by discontinuous culture with glucagon for 48 h in terms of -AUC: however the secretion index was not significantly improved, and this means that porcine islets remain poorly effective when compared, for instance, to human islets or rat islets (Wogensen et al 1988, Giannarelli et al 1993, Hegre et al 1993, Takei et al 1994). …”

“…Despite these encouraging results, the in vitro physiology of porcine islets has not yet been examined in detail. Their in vitro insulin release after an acute glucose stimulus is weak (Marchetti et al 1989, Crowther et al 1990) when compared with the insuhn release from rat or human islets (Giannarelli et al 1993, Hegre et al 1993, Takei et al 1994 or to the insulin release induced in pig islets by glucose plus IBMX, a phosphodiesterase inhibitor (Heald et al 1992). In this study, porcine islets cultured overnight showed no insulin response to glucose, as already reported (Davalli et al 1993), and the insulin response was still low after 48-h culture in CMRL 1066.…”

Islet architecture: A comparative study

“…What escapes this proportionate expansion is the size distribution of islets. Large animals such as humans share similar islet sizes with mice,14,15 suggesting that this micro-organ has a certain size limit to be functional. The inability of large animal pancreata to generate gigantic islets can be compensated by an increase in the number of islets.…”