Chronic nephrotoxicity of soluble nickel in rats.

1. Male and female Wistar rats were given 100 mg L-1 of nickel (as nickel sulfate) in drinking water for 6 months. Lactate dehydrogenase, total proteins, N-acetyl-beta-D-glucosaminidase (NAG), albumin and beta 2-microglobulin were measured in 24 h urine after 3 and 6 months of exposure. Body and kidney weights were also recorded. 2. After 6 months, urinary excretion of albumin in control and exposed rats was 354 and 1319 micrograms 24 h-1 for female rats (P < 0.05) and 989 and 2065 micrograms 24 h-1 for male rats (P = non significant). Kidney weights were significantly increased in the exposed groups. No significant changes were observed in other parameters. 3. The results suggest that low-level oral exposure to soluble nickel either induces changes of glomerular permeability in female and possibly in male rats, or enhances the normal age-related glomerular nephritis lesions of ageing rats. The intake was probably not high enough to induce significant tubular changes. The female rat seems to be more sensitive to the nephrotoxic effect of nickel than the male rat.