FUNCTIONAL AND MORPHOLOGICAL ASPECTS OF THALLIUM-INDUCED NEPHROTOXICITY IN RATS

Until now the effect of thallium (Tl) on renal function has not been i nvestigated systematically. Therefore, the dose (5, 10, 15, 20 mg Tl2S O4/kg body wt., intraperitoneally) and time-dependence of renal damage was investigated in diuresis experiments on conscious rats. Morpholog y was evaluated after perfusion fixation in situ. Morphologic changes were localized in the thick ascending limb of the loop of Henle, mostl y expressed at the 2nd day after Tl administration, which were complet ely normalized again at the 10th day. Other parameters such as Tl conc entration, changes in water content and the activity of Na+/K+-ATPase as well as the diuretic effect of furosemide confirmed the Tl effect t o be localized in the renal medulla. One single Tl administration is f ollowed by a decrease in glomerular filtration rate (GFR) and urine vo lume and an increase of proteinuria. Electrolyte excretion was only sl ightly changed. All changes were reversible within the 10-day investig ation period.