Renal tubular handling of zinc in the dog.
Victery-W; Smith-JM; Vander-AJ
Am J Physiol, Lung Cell Mol Physiol 1981 Nov; 10(5):F532-F539
Renal clearance of zinc (7440666) was investigated in dogs. Anesthetized dogs were given catheters of polyethylene tubing in cephalic and femoral veins and one femoral artery. The right ureter was catheterized. Stop flow experiments were performed to determine creatinine clearance and water reabsorption. Dogs were given an infusion containing zinc-65 (13982393) (Zn-65) with various amounts of zinc-chloride (7646857) as carrier. Clearance of Zn-65 was determined. Standard stop flow experiments were conducted. Samples were counted, and creatinine was measured in urine and ultrafiltrable samples. Net reabsorption averaging approximately 95 percent was the dominant tubular mechanism for renal handling of acutely administered zinc. Fractional zinc excretion was significantly elevated. Treatment with chlorothiazide (58946) lowered the ultrafiltrable Zn-65, but increased fractional excretion by about 300 percent. Cysteine (52904) and histidine (71001) infusion elevated the percentage of ultrafiltrable Zn-65 by 20 and 20 times, respectively. The net reabsorption that occurred in the segment corresponding to distal reabsorptive minimum for sodium was strikingly increased for Zn-65 in stop flow patterns. Proximal reabsorption of zinc was not obvious in normal stop flow patterns. The authors conclude that the combination of clearance and stop flow techniques reveals that the amount of zinc excreted is normally the result of filtration and reabsorption. Chlorothiazide induces far distal secretion, and citrate and amino acids influence infiltration and reabsorption.
NIOSH-Publication; NIOSH-Grant; Animal-studies; Light-metals; Radiochemical-analysis; Acute-exposure; Biological-effects; Physiological-response; Medical-research; Histochemical-analysis; Excretion
Physiology University of Michigan 6811 Medical Science II Ann Arbor, Mich
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American Journal of Physiology: Lung Cellular and Molecular Physiology
University of Michigan at Ann Arbor, Ann Arbor, Michigan