Actions and interactions of aldosterone monoacetate and neurohypophysial hormones on the isolated cat kidney

Abstract

Intravenous infusions of quantities of aldosterone too small to affect renal function raised the concentration of potassium in the plasma of cats under chloralose anaesthesia (Davey & Lockett, unpublished). This observation indicated extra-renal action of the hormone and raised the question whether the effects of aldosterone on renal function were predoininantly the result of the direct action of this compound within the kidney itself or were, in large part, the consequence of its extra-renal effects. The existence of extra-renal actions of mineralocorticoids is well known; they have been described by Wilson (1957) and Flanagan, Davis & Overmann (1950) amongst others. There has, however, been no direct demonstration of the intrarenal effects of aldosterone under conditions which exclude the possibility of extra-renal effects. The nearest approach to such conditions is found in the work of Barger, Berlin & Tulenka (1958) and of Ganong, Mulrow & Hollinger (1957). Barger and his collaborators studied the effect of infusions of aldosterone into the left renal artery of the dog. Unilateral effects were observed in some of their experiments, but these were preceded by a long latent period, and no observations were made of the effect of their infusions on the concentrations of electrolytes in plasma. Ganong and his colleagues used larger doses of aldosterone and were unable to show that the kidney which received the intra-arterial injection of hormone responded either more markedly or more rapidly than did the other.The object of our experiments was therefore to study the renal actions of aldosterone in kidneys perfused with blood and isolated from all nervous and hormonal continuity with the animal body. METHODSThe cats used were of male, female or neuter sex and weighed from 1-3 to 4-6 kg. Young animals were commonly selected to provide the heart-lung-kidney preparations and the older aniimals were used as blood donors. Only lactating females or those in advanced stage

Hormonal factors affecting sodium excretion in the rat

“…Both hypophysectomized rats (Table 2) and cat's kidneys perfused with blood from headless or hypophysectomized donor animals (Davey & Lockett, 1960) a-g inclusive caused urinary loss of salt and water, those at h, j and k did not. ACO, anterior commissure; C, cerebellum; CC, corpus callosum; CH, cerebral hemisphere; CQ, corpora quadrigemina; F, fornix; P, pons; PC, posterior commissure; Pi, pineal.…”

“…Experiments on the isolated perfused kidney of the cat by Davey & Lockett (1960), and de Lima, Lockett & Roberts (1961) have shown that the actions of aldosterone in this preparation differ from those usually observed in intact animals, and are modified by substances derived from the hypophysis. Physiological concentrations of aldosterone have a diuretic naturetic effect on these kidneys when they are being perfused with blood from headless or hypophysectomized donor animals.…”

Interaction of aldosterone and oxytocin to influence renal sodium excretion in rats

“…For example, combined oxytocin and aldosterone produced a much larger increase in Na+ transport in the toad bladder than observed when either of the hormones were added separately (Girardet, Geering, Gaeggler & Rossier, 1986). Davey & Lockett (1960) also proposed that aldosterone interacts with oxytocin to influence renal Na+ handling. The current study was designed to investigate the possibility of such an interaction.…”

The Influence of Heparin and of Section of the Buffer Nerves on the Responses of the Cat Kidney to Saline‐loading

“…. 1966aDavey and Lockett, 1960) nnder cbloralose anaestbesia. Tbe blood used to fill tbe perfusion eirciiit was collected from male, female or neutered cats wliich were either intact (8 experiments) or in which the brachiocephalic and L-subclavian arteries had been ligatured (headless donors) for 13-21 min.…”