Abstract
Nine dogs, anesthetized with Evipan-sodium, were used in the experiments. The adrenal venous blood was collected by the lumbar route method of Satake et al. and its adrenaline content was estimated chemically by the method of Bloor and Bullen. In dogs, whose splanchnic nerves were cut about 2 hours before the onset of the experiments, the adrenaline secretion rate was increased markedly by the intravenous injection of acetylcholine before administering hexamethonium. After hexamethonium, however, no definite increase in the secretion rate was elicited by acetylcholine.
In dogs, whose splanchnic nerves were cut 2 or 3 weeks before experiments, a considerable increase in the secretion rate was induced by injection of acetylcholine even after administering hexamethonium, although it was smaller than that before hexamethonium.
Thus it may be reasonable to conclude that the suppressive effect of hexamethonium on the adrenal medullary response to acetylcholine is definitely reduced by the chronical denervation of the adrenal gland, but not by the acute denervation.
