Abstract
Experiments were done in dogs anesthetized with Nembutal. Adrenal venous blood was collected and analyzed for adrenaline and noradrenaline by the fluori-method. In intact dogs insulin hypoglycemia was accompanied by a marked metric increase in adrenal medullary secretion. In dogs whose spinal cord was transected at the level of the lowest cervical segment one or 4-7 days previously, the adrenal medullary secretion was increased significantly by insulin hypogly-cemia. The magnitude of increase in these dogs was, however, far smaller than that in intact ones. Section of the splanchnic nerves abolished almost com-pletely the rise in adrenal medullary secretion of the ipsilateral gland in response to insulin hypoglycemia. It is concluded that although the thoracic (or thoracico-lumbar) spinal center is sensitive to hypoglycemia and plays some role in promoting adrenal medullary secretion, the upper center situated above the level of spinal cord transection plays a more essential role for the adrenal medullary response to hypoglycemia.
