Resynthesis of Catecliol Hormones in the Cat's Adrenal Medulla

Abstract

Summary. Repeated injections of nicotine tartrate in doses of 0.05–0.8 mg per kg in the cat cause a release of catechol amines in the adrenal venous blood, sometimes exceeding the loss in the gland compared with the control gland. The rapid resynthesis observed in some cases after nicotine injections was not observed when nicotine was infused over a period of 60–107 min in doses of 0.04–0.13 mg/kg/min. Increasing doses of nicotine within the dose range 0.1–0.4 mg/kg increased the release of adrenaline while doses of 0.8 mg/kg caused a rise also of noradrenaline. The release of catechol atmines during electrical stimulation uf the splanchnic nerve wts often considerably in excess of the loss in the stimulated gland. The maximal resynthesis of adrenaline corresponded to 325 μg per g gland and of noradrenalirie 745 μg per p gland.

Noradrenaline: Fate and Control of Its Biosynthesis

“…After prolonged stimulation of the splanchnic nerve the sum of the amount of catecholamines released together with the amount remaining in the gland is greater than that initially present in the gland (74).' This indicates that nerve impulses increased the biosynthesis of catecholamines.…”

Cholinoceptor regulation of cyclic AMP levels in bovine adrenal medullary cells

“…During stimulation of secretion from the adrenal medulla, substantial quantities of catecholamines are released; however, little depletion of adrenaline or noradrenaline occurs from the adrenal gland. These findings suggested that, during periods of increased secretion, the adrenal chromaffin cells increase their synthesis of catecholamines to replenish and maintain their secretory reserves (Bygdeman & von Euler, 1958). The coupling between secretion and catecholamine biosynthesis ('stimulation-secretion-synthesis coupling') is likely to be the result of second messengers generated in the chromaffin cells.…”

“…These findings suggested that, during periods of increased secretion, the adrenal chromaffin cells increase their synthesis of catecholamines to replenish and maintain their secretory reserves (Bygdeman & von Euler, 1958). The coupling between secretion and catecholamine biosynthesis ('stimulation-secretion-synthesis coupling') is likely to be the result of second messengers generated in the chromaffin cells.…”

Adrenal Medullary Insufficiency in Severe Thermal Burn *

“…This explanation seems especially logical since the resynthesis of adrenaline is normally quite rapid (23)(24)(25).…”

“…It is further known that the adrenal gland normally synthesizes adrenaline with such rapidity (23)(24)(25) that only under unusual circumstances can the adrenal medulla be depleted of its adrenaline supply (1,3). It has been shown that most patients who survive severe thermal burns excrete daily large amounts of adrenaline and noradrenaline, and that this elevated rate of excretion continues for weeks without any recognizable failure in the adrenal gland's ability to produce adrenaline (7).…”