Characterization of trihalomethane (THM)-induced renal dysfunction in the rat. I: Effects of THM on glomerular filtration and renal concentrating ability.

Single non-lethal doses (3 mmol/kg) of chloroform (CHCl3), dichlorobromomethane (CHCl2Br), dibromochloromethane (CHClBr2), and bromoform (CHBr3) were administered by intraperitoneal injection to male Sprague-Dawley rats and glomerular filtration and renal concentrating ability were assessed at varied times (5-8 h, 21-24 h, and 45-58 h) following treatment. At this dose, each of the four trihalomethanes (THMs) elevated blood urea nitrogen (BUN) and reduced renal concentrating ability (as measured by H2O intake/output ratios, urinary total osmolality, and electrolyte levels). Three of the four THMs also significantly reduced glomerular filtration rate (GFR), with only CHCl3 failing to demonstrate an effect at 3 mmol/kg. In general, CHCl2Br demonstrated the greatest interference with these renal function parameters. The times of maximal THM-induced effect on BUN and glomerular filtration rate were observed to be 24 h and 21-24 h post-treatment, respectively. These data suggest that a single acute THM treatment can inhibit mammalian renal concentrating ability and glomerular filtration.