Transport of organic compounds in renal plasma membrane vesicles of cadmium intoxicated rats.

Abstract

Effects of cadmium intoxication on renal transport systems for various organic compounds were studied. Subcutaneous injections of CdCl2 (2 mg Cd/kg.day) for two to three weeks induced marked polyuria, glycosuria, and proteinuria without altering glomerular filtration rate. In renal cortical brush border membrane vesicles (BBMV) isolated from cadmium treated rats, Na(+)-dependent D-glucose uptake was markedly attenuated, and this was due to reduction in Vmax and not Km. Likewise, Na(+)-driven L-glutamate transport and H(+)-driven tetraethylammonium transport were significantly reduced. In renal cortical basolateral membrane vesicles (BLMV) of cadmium intoxicated rats, Na(+)-dependent succinate transport was drastically reduced. These results indicate that cadmium intoxication impairs various transport systems for organic compounds in the brush border and basolateral membranes of proximal renal tubules.