Release of Medullary Amines From the Isolated Perfused Adrenal Gland of the Dog

Abstract

In a previous paper (Muscholl & Vogt, 1964) the release of catechol amines from extramedullary chromaffin tissue had been examined, and certain differences found between the responses of extramedullary chromaffin cells perfused with Locke solution and the well-known reactions of the adrenal medulla in situ. Thus electrical stimulation of preganglionic fibres to the ganglion containing the chromaffin tissue did not cause a release of adrenaline or noradrenaline, as does stimulation of the nerve supply to the adrenal medulla. Furthermore, injection into the perfusion fluid of bradykinin or angiotensin had little or no stimulant action on extramedullary, but was known to have powerful action on medullary chromaffin tissue.The present work was undertaken in order to find out whether these differences were due to the one tissue having been studied while the circulation was intact and the other while perfused with Locke solution, or whether the differences were inherent in the nature of the two tissues. The effect was therefore examined of stimulation of the splanchnic nerves and of the injection of a series of drugs including angiotensin and bradykinin on release of adrenaline and noradrenaline by the dog Locke-perfused isolated adrenal gland. METHODSConditions for the perfused adrenal medulla were made as similar as possible to those used for the perfusion of the extramedullary chromaffin tissue (Muscholl & Vogt, 1964). Puppies (bodyweight 2.2 to 7.5 kg) were used as donors as before, and the composition and temperature of the Locke solution, perfusion apparatus, pressure head, and gassing mixture were the same. The dissection was that used for perfusion of dog adrenals with blood (Vogt, 1951), but the adrenal gland, attached to a segment of aorta and a length of vena cava, both of which had been completely separated from the rest of the body, was cut out and placed on a small platform sunk into a polyethylene funnel from which the effluent fluid escaping from the opened vena cava was collected. Perfusion was through the superior mesenteric artery, and was started while the adrenal gland was still in situ, just as described previously for the tissue supplied by the inferior mesenteric artery. The flow through the adrenal gland was faster than through the extramedullary chromaffin tissue and ranged from 3 to 9 ml./min. Collection periods usually lasted 2 min; either the whole or one-half of such a 2-min sample was extracted, and the catechol amines were separated and assayed as in the earlier work. Recoveries of the amines averaged 70%.The following drugs were used: angiotensin (Hypertensin II aspartic-,B-amide, Ciba), bradykinin (Parke Davis), dimethylphenylpiperazinium iodide (Parke Davis), histamine bis-(dihydrogen phosphate) (B.D.H.), 2,4,5-trihydroxyphenylethylamine (6-hydroxydopamine) hydrobromide (Merck, Sharp & Dohme), methylreserpate methyl ether hydrochloride (Su 8842. Ciba), reserpine (Serpasil, Ciba) and tyramine hydrochloride.

The Effect of Prenylamine on the Metabolism of Catechol Amines and 5‐hydroxytryptamine in Brain and Adrenal Medulla

“…Reserpine does not release amines from the perfused adrenal medulla (Vogt, 1965). If the release caused by prenylamine is regarded as an artefact, the absence of action on the adrenal medulla would represent one more instance in which the two substances resemble each other.…”

“…Dog isolated adrenal glands were perfused by gravity at 350 C with Locke solution gassed with a stream of 5% carbon dioxide and 95% oxygen. Details of the dissection are published elsewhere (Vogt, 1965). Difficulties were encountered by cloudiness forming when the 5%, prenylamine gluconate was diluted with Locke solution; this was prevented by diluting with bicarbonatefree Locke solution, saturating the mixture with 5% carbon dioxide and 95% oxygen, and adding the bicarbonate last.…”

Preferential secretion of adrenaline or noradrenaline by the cat adrenal in vivo in response to different stimuli

“…Thus, although electrical stimulation of the cat's hypothalamus altered the composition of the catecholamines secreted from the adrenal glands (Folkow & von Euler, 1954) and, in the dog, electrical stimulation of the splanchnic nerves innervating the adrenal gland (either intact or perfused) changed the composition of the catecholamines released from the gland (Mirkin, 1961 ;Vogt, 1965), no effective regulation of the amount of these amines was found in the dog by Lund (1951). Experiments on the perfused adrenal glands of cats have shown that pilocarpine, histamine, muscarine and polypeptides such as bradykinin, kallidin and angiotensin elicited a preferential release of adrenaline when added to the perfusion medium; nicotine and KCl released principally noradrenaline (Rubin & Miele, 1968;StaszewskaBarczak & Vane, 1967).…”

The effects of bradykinin, angiotensin and acetylcholine on the bovine adrenal medulla

“…The poor response of the adrenal medulla of more mature calves was particularly surprising in view of the previous reports of peptide-induced secretion in other species (Feldberg & Lewis, 1964, 1965StaszewskaBarczak & Vane, 1965, 1967Piper & Vane, 1967). In the present experiments the amounts of noradrenaline and adrenaline released by angiotensin and bradykinin were only marginally above the resting output from the medulla, whereas stimulation of the splanchnic nerve or the injection of acetylcholine induced a 10-100 fold increase in output.…”

“…The cause of this increased sensitivity, which lasts for a considerable time, is unknown. It is possible that peptides such as bradykinin or angiotensin could be involved, for reports of their potent action on the adrenal medulla of the adult rabbit (Lecomte, Troquet & Dresse, 1961), cat (Feldberg & Lewis, 1964, 1965, dog (Staszewska-Barczak & Vane, 1965, 1967 and guinea-pig (Piper & Vane, 1967) suggested that these peptides might be necessary for the release of stored catecholamines. The effects of bradykinin and angiotensin on the adrenal medulla have therefore been examined in young calves 24 hr after birth and have been compared with results obtained in more mature animals and in adult cats.…”