[Possible direct action of hypothalamic factors on the development of pancreatic hormonal activity]

Possible mechanisms of hypothalamic control of the pancreas endocrine function in prenatal ontogenesis were investigated. For this purpose reactivity of pancreatic B-cells to glucose was studied in vitro and in vivo on rat fetuses. Incubation of pancreas fragments of encephalectomized fetuses in the medium containing preincubated hypothalamus fragments of adult rats, newborn rats or 21.5-day old fetuses did not compensate the operation effects. The glands remained refractory to glucose. Similar results were obtained with the introduction of hypothalamus homogenate to decapitated fetuses. Hypothalamus homogenate did not reduce the response to glucose in the absence of hypophysis. The data obtained indicate that hypothalamic insulinotropic factors have no direct action on the insular tissue of the fetus, the effect being hypophysis-mediated.