Comparative Investigations on the Effects of Acute Intraperitoneal Cadmium, Chromium, and Mercury Exposure on the Kidney

Abstract

Urinary excretion of lactate dehydrogenase (LDH), glutathione-S-transferase (GST), leucine arylamidase (LAS), γ-glutamy transferase (GGT), β-galactosidase (GAL), β-N-acetyl-D-glucosaminidase (NAG), sodium, and glucose were determined in female Sprague-Dawley rats the subsequent three days after intraperitoneal treatment with single doses of 4.5 mg CdCl₂ × 1H₂O/kg, 20 mgNa₂CrO₄/kg, and 0.75 mg HgCl₂/kg body weight. Although the pathological effects were localized within the same part of the nephron (i.e., the proximal tubule), there were marked differences with regard to the extent and time course of the parameters affected. Treatment with cadmium resulted essentially in a marked decline in sodium and glucose excretion. The administration of chromate led to a slightly to moderately elevated excretion of the enzyme activities measured with the cytosolic LDH as the most increased enzyme (ca. 500% of controls on Day 3 postadministration). Median glucose excretion was unaffected whereas sodium excretion was transiently reduced. The maximum of enzyme excretion after HgCl₂ was essentially the same on the first day postadministration and the amount of enzyme activity in urine up to 20 times higher compared to that after chromium. Sodium excretion was below that of controls on Days 2 and 3, whereas glucose excretion was markedly elevated (up to 8000% of controls). The results indicate that it is possible to discriminate with the use of selected urinary enzymes, substrates, and electrolytes various kinds of nephrotoxic actions not only in different but also within the same part of the nephron.