Hormone regulation of adrenaline and noradrenaline release in the inferior mesenteric ganglion of the dog

Abstract

Studies were carried out on perfused sympathetic ganglia to determine the actions of hormones on their states and functions. The effects of hormones, hydrocortisone, cortin, prostaglandin E 2 (PGE 2), insulin, and triiodothyronine, on the release of adrenaline (A) and noradrenaline (NA) into the superfusate of the inferior mesenteric ganglion (IMG) of the dog were studied in rest and during 3 stimulations: (1) electrical stimulation of lumbar splanchnic and (2) hypogastric nerves; and (3) after acetylcholine application. Hydrocortisone and PGE 2 do not affect A and NA release during all stimulations. Cortin increases the process during (2) and (3). Insulin increases the release of A, though not affecting NA during stimulations 1–3. Triiodothyronine increases the release of NA and decreases that of A during all 3 influences. The mechanism of hormonal action on catecholamine (CA) release by the ganglion's adrenergic structures is discussed, and the presence of insulin receptors in them is suggested.