Effects of intermittent hypoglycaemia in pregnant rats on the functional development of the pancreatic B-cells of their offspring.

Intermittent hypoglycaemia was induced by insulin injections into pregnant rats. At birth, the pups body weight and pancreatic insulin content were slightly but significantly decreased. In contrast, the B-cells of these newborn rats responded more markedly to a glucose challenge than the controls. The pancreases of the insulin injected rats were grearly depleted of insulin, possibly because of feedback inhibition of insulin synthesis by exogenous insulin. This inhibitory effect was restricted to the mother since the injected insulin did not cross the placental barrier. It is proposed that the nutrient supply to the fetus influenced body growth and pancreatic insulin accumulation whereas blood glucose variations, even intermittent hypoglycaemia, promoted precocious maturation of the B-cell glucoreceptor system.