Effects of lead on the secretion and disappearance of renin in rabbits.
Keiser-JA; Vander-AJ; Germain-CL
Toxicol Appl Pharmacol 1983 Jun; 69(1):117-126
The effects of lead (7439921) exposure on renin production and secretion were evaluated in rabbits. Male New-Zealand-rabbits received an infusion of 0.3 to 2.0 milligrams per kilogram (mg/kg) lead-acetate (301042) or sodium-acetate (controls) through a jugular cannula; 2 hours later the kidneys were removed and ten blood samples drawn within the next hour. Rabbits also received 0, 500, or 1000 parts per million (ppm) lead in drinking water; at 7 weeks, rabbits were nephrectomized and ten blood samples drawn over an hour. Cortical slices were made from chronically lead exposed rabbits and treated with 5 or 35 millimoles (mmol) potassium. Renal cortical slices from untreated rabbits were exposed to 0, 0.0001, 150 minutes of incubation. Plasma renin activity (PRA) was measured in blood samples and tissue samples were tested for renal renin. In acute lead exposure, PRA in control animals diminished from 70 to 35 percent of initial PRA, while in lead exposed animals PRA never fell below 70 percent of the initial value. In chronically lead exposed animals, PRA diminished to 40 percent of initial values in those receiving 1000ppm lead and to 30 percent in those receiving 500ppm; these values were similar in controls. Renin secretion from cortical slices from pretreated rabbits was greatest in the 500ppm group; stimulation of renin secretion with 5mmol potassium ion increased renin secretion 3 fold. Slices from control rabbits incubated in 0.0001 molar lead secreted renin at approximately 86 percent of the value for no lead control flasks. Mean secretion from slices incubated in 0.000010 molar solution lead was 79 percent of no lead controls. The authors conclude that in acute lead exposure both renin secretion and clearance are inhibited while chronic exposure affects only secretion.
Lead-poisoning; Animal-studies; Dose-response; Chronic-exposure; Acute-exposure; Biological-effects; Enzyme-activity; Vasoactive-agents; Physiological-chemistry
Other Occupational Concerns; Grants-other
Toxicology and Applied Pharmacology
University of Michigan at Ann Arbor, Ann Arbor, Michigan