Influence of Stress, Adrenalectomy and Age on the Stimulation in vitro of Rat Kidney ATPase by Angiotensin

L evin , K. Influence of stress, adrenalectomy and age on the stimulation in vitro of rat kidney ATPase by angiotensin . Acta physiol. scand. 1970. 79 . 50–57. The previously demonstrated stimulation of kidney ATPase by angiotensin was studied with respect to variations due to stress, anesthesia, noradrenaline activity, adrenal function and age of the animals. The kidney cortex ATPase from rats subjected to stress, pain or angiotensin injection could not be activated in vitro by angiotensin. This was considered to be due to a maximal stimulation of the enzyme already at sacrifice of the animals. The susceptibility of the enzyme to angiotensin stimulation disappeared after adrenalectomy, but remained if the animals were treated with aldosterone. Angiotensin had no stimulating effect on the kidney cortex ATPase in newborn rats, the effect reached a maximum when the animals weighed 150–200 g and again disappeared when the animals grew larger.