H. Moes et Tr. Koiter, RAT PANCREATIC-ISLET FUNCTION DURING PROLONGED GLUCOSE STIMULATION IN-VITRO - EFFECT OF SEX AND REPRODUCTIVE STATE, Medical science research, 25(1), 1997, pp. 23-25
Prolonged stimulation with glucose may induce desensitisation of pancr
eatic beta-cell function in male rats. The effects of such a treatment
on pancreatic islets of pregnant (P) rats, in which beta-cell functio
n is enhanced, were studied in a perifusion design and compared with t
he effects on islets of cyclic female (C) and male (M) rats. The treat
ment induced in all three groups of islets a transient increase in bot
h insulin and amylin secretion, followed by a gradual decline (desensi
tisation). Islets of P-rats released more insulin, but not amylin, tha
n the other types of islets. Furthermore, desensitisation occurred lat
er in islets of P-rats (after 2.5 h) than in islets of C- and M-rats (
after 0.5 h) The amount of insulin, but not of amylin, stored in islet
s of P-rats was also much higher than in the islets of C- and M-rats.
Glucagon release in all three groups of islets was suppressed during g
lucose stimulation, but tended to increase again after 3 h of continuo
us stimulation. It is concluded that the control of beta-cell function
is similar in M- and C-rats, but is significantly altered in P-rats.
It is suggested that desensitisation of the beta-cells is associated w
ith desensitisation of the alpha-cells.