Angiotensin II has been shown to increase the excretion (1) and secretion (2) of aldosterone by normal human subjects, and the secretion of aldosterone by hypophysectomized, nephrectomized dogs (3)(4)(5). In the latter preparation (3), renin, which leads to the liberation of angiotensin in the circulation (6), has been shown to stimulate aldosterone secretion. The present studies were done to determine whether angiotensin and renin can act directly on the adrenal cortex. The slices were minced with scissors and weighed. Specimens weighing about 500 mg were placed in 5 ml of Krebs-Ringer bicarbonate medium containing glucose in a concentration of 200 mg per 100 ml. At least 4 vessels were incubated and analyzed separately for each portion of each experiment. Thus, there were at least 4 control vessels and at least 4 with each precursor or stimulating agent studied in each experiment. The tissues were kept chilled until incubation, which was started between 3 and 5 hours after the death of the cattle. Tissues were preincubated for 1 hour at 37°C under 5 per cent CO2-95 per cent 02 on the Dubnoff metabolic shaker. The preincubation medium was removed, and 5 ml of fresh medium was used to transfer the slices to vessels to which the appropriate precursor had been added with or without ACTH, renin, or angiotensin II. Incubation was for 2 hours.The control values for synthesis of aldosterone by the adrenals in vitro showed wide variations from experiment to experiment. The higher the control value, the less was the effect of any given stimulus. Thus, when production of aldosterone by the control beef slices was greater than 2 gsg per g of tissue per hour, experimental procedures produced little or no increase of synthesis. Therefore, only preparations with control values below 2 ,lg per g per hour are included. Factors which may have affected the control level of aldosterone production were water and salt deprivation. Control values were above 4 ,ug per g per hour only during the winter months when the ground was frozen and the cattle had no access to water for at least 24 to 48 hours before slaughter and limited access to water and salt for a longer period. A stimulatory effect of water deprivation on synthesis of aldosterone in vivo (7) and of salt depletion on synthesis in vitro (8) has been observed. Other factors may have led to this seasonal variation, a problem noted by others studying corticosteroid synthesis in vitro (9).The capacity of the tissue to respond to any given stimulus was found to decrease with the passage of time, so this was kept relatively constant in all experiments.Rat adrenal sections. The technique of Saffran and Schally (10) was closely followed. A quarter of one adrenal gland from each of eight 150-to 200-g SpragueDawley male rats was included in each of four vessels 715
Summary: Autonomic nervous system integrity has been assessed in 30 alcoholic subjects and 30 agesex matched controls using five simple tests of cardiovascular responses. There was evidence of parasympathetic neuropathy alone in five of the alcoholic subjects (16%) and of combined parasympathetic and sympathetic neuropathy in an additional six (20%). None ofthe controls showed any abnormality. Within the alcoholic group, those with autonomic neuropathy were older, were more likely to be female and to have established alcoholic liver disease. Symptoms were a poor guide to the presence or absence of autonomic neuropathy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.