Clearance of renin in unanesthetized rats: effects of chronic lead exposure.
Keiser-JA; Vander-AJ; Germain-CL
Toxicol Appl Pharmacol 1983 Jun; 69(1):127-137
The effect of chronic lead (7439921) (Pb) exposure on the steady state clearance of exogenous homologous renin was investigated in rats. Male Charles-River-rats were divided into two treatment groups. The first group was given 500 parts per million (ppm) Pb as lead-acetate (301042) in their drinking water for 14 to 15 weeks. The second group served as controls and drank tap water. In a second experiment rats received 1000ppm Pb in their drinking water for 15 to 16 weeks. The day before the renin clearance experiment, heparinized catheters were inserted into the left jugular vein and carotid artery for infusion and sampling. Blood samples were obtained at 0, 30, 75, and 90 minutes via the arterial line. After the initial blood sample an infusion of sulfobromophthalein (71670) (BSP) was initiated at a dose of 17.5 milligrams per kilogram (mg/kg) followed by a constant infusion of 0.63mg/kg. After 30 minutes BSP clearance determination was obtained and renin infusion began. Blood samples were obtained at 75 and 90 minutes for determination of BSP and renin. At the completion of the experiment the animals were sacrificed and the kidneys were analyzed. Rats exposed to 500ppm Pb had basal plasma renin concentrations (PRCs) of 12 nanograms per milliliter per hour (ng/ml/hr) compared to only 7.6ng/ml/hr for the time control group. Rats exposed to 1000ppm Pb did not have higher PRCs than the controls. The renin infusions produced an 8 to 10 fold elevation in PRCs above basal amounts. At no time were there any significant differences between the Pb treated rats and the control groups with respect to the clearance of renin. There was no significant differences in the clearance of BSP between any of the groups. The kidneys of the rats in the 500ppm Pb treated group had elevated renin concentrations. Concentrations of 1426 micrograms were determined compared to 1065 micrograms found in the kidneys of the control group. The authors conclude that the clearance of renin is not altered by chronic Pb exposure at either 500 or 1000ppm doses.
NIOSH-Publication; NIOSH-Grant; Grants-other; Animal-studies; Heavy-metal-poisoning; Chronic-exposure; Metabolic-study; Excretion; Quantitative-analysis; Medical-research; Dose-response; Blood-analysis
Physiology University of Michigan 6811 Medical Science II Ann Arbor, Mich
7439-92-1; 301-04-2; 71-67-0
Other Occupational Concerns; Grants-other
Toxicology and Applied Pharmacology
University of Michigan at Ann Arbor, Ann Arbor, Michigan