GLUCOSE STIMULATION OF INSULIN SECRETION FROM ISOLATED PANCREAS OF FOETAL AND NEWBORN RATS

Pancreatic glands of 22-day-old rat foetuses or 0-12 day old rats were incubated in a Krebs-Ringer phosphate-buffered salt solution, and the insulin secretion measured at a lower (0.6 mg/ml) or a higher (3 mg/ml) glucose concentration in the medium. Stimulation of the insulin release by glucose could not be detected until the second postnatal day, when there was a marked increase in the amount of hormone secreted into the medium. Since the presence of insulin has been demonstrated in the B-cells of rat foetuses, the data suggest that in this species the cellular mechanism for insulin synthesis becomes manifest considerably earlier than that for glucose-regulated insulin release. © 1969 Springer-Verlag.