Changes in plasma renin activity and renal immunohistochemically demonstrated renin in carbadox treated pigs.

Carbadox is known to induce toxic effects on the adrenal cortex, resulting in hypoaldosteronism. To study the involvement of carbadox on the renin-angiotensin system, weaned piglets of five weeks old received feed supplemented with 0 (control group), 50, 100, 150 or 200 ppm carbadox. After four weeks the 100 and 150 ppm groups had significantly higher plasma renin activity levels than the control group and after nine weeks plasma renin activity levels of all treated groups were significantly higher than the control group.

Bioavailability of beta-carotene in humans.

Normal healthy volunteers were studied after they ingested various beta-carotene doses. Daily administration of 15 or 45 mg beta-carotene resulted in significant increase in plasma beta-carotene levels. The extent of increase and the pattern of plasma beta-carotene levels showed substantial interindividual variation.

Hormonal effects of smoking--I: Effects on plasma renin activity.

It is generally recognized that smoking is associated with an increased risk for the development of coronary artery disease. Since it has been suggested that increased plasma renin activity (PRA) may be a risk factor for cardiovascular disease, PRA was measured in a group of smokers and nonsmokers. PRA was measured under basal conditions, following intravenous (IV) furosemide administration and after a short burst of smoking.

Hormonal effects of smoking--II: Effects on plasma cortisol, growth hormone, and prolactin.

Effect of smoking on the plasma levels of cortisol, growth hormone, and prolactin was evaluated in a group of smokers and nonsmokers. Plasma levels of these hormones were measured under basal conditions and following a short burst of smoking. In addition, to determine the mechanism of action of nicotine on the release of these hormones, rat renal cortical slices were incubated with nicotine and the generation of cyclic AMP was measured in vitro.

Immunoelectron microscopic localization of renin in the juxtaglomerular cells of the amphibian Bufo bufo.

The ultrastructural localization of renin in the juxtaglomerular apparatus of the kidney of the toad Bufo bufo has been examined using an immunogold staining method for electron microscopic immunocytochemistry and an antiserum to renin isolated from the submandibular gland of the mouse. Renin immunoreactivity was confined to lamellated granules in the cytoplasm of epitheloid or juxtaglomerular cells in the glomerular afferent arterioles and also in the media cells of larger arteries. Mouse kidney tissue, examined for purposes of comparison, showed immunolabeling limited to the granules of the juxtaglomerular cells.