Ontogenetic aspects of thallium-induced nephrotoxicity in rats.

The effect of Tl2SO4 (Tl, 20 mg kg-1 body wt.) on renal function was investigated in 10- and 20-day-old rats. Nephrotoxic effects were evaluated by the determination of glomerular filtration rate, urinary volume, electrolyte and protein excretion, as well as by morphological investigations. In contrast to adult rats there were no morphological destructions in 10- and 20-day-old rats. Changes in renal function seemed to be less expressed in 10- and 20-day-old than in adult rats. The smaller nephrotoxicity in 10-day-old rats may be caused by lower Tl concentration in renal tissue, whereas in 20-day-old rats decreased nephrotoxicity cannot be explained in this way. The activity of Na+/K(+)-ATPase in rat renal tissues was found to be involved in the mechanisms of Tl enrichment in renal tissue, being an indirect determinant of Tl nephrotoxicity.