The Rat (Rattus norvegicus) as a Model Object for Acute Organophosphate Poisoning. 5. Morphofunctional Alterations in Kidneys

In two rat models of acute paraoxon (POX) poisoning against the background of specific and nonspecific inhibition of blood plasma carboxyl esterase (CE) activity, the POX effect on morphology and functions of the rat kidneys was assessed within a period from 1 day to 6 weeks after the poisoning. During the first 3 days, rats developed transient glycosuria and increased urinary excretion of calbindin and sulfated glycosaminoglycans. One day after the poisoning, a positive reaction for protein deposits (AFOG+) was observed in the descending and ascending limbs of the loop of Henle and collecting ducts against the background of nonspecific CE inhibition. After 2 weeks, the AFOG+ reaction was detected in the proximal straight tubules along with desquamation of epithelial cells. Both 3 days and 2 weeks after the poisoning, regardless of the mode of CE inhibition, a morphometric analysis of individual components of the rat nephron revealed an increase in the size of the renal corpuscle and the glomerular capillary tuft within the Bowman’s capsule. Three days after the poisoning and at every subsequent observations, intoxicated rats exhibited an alteration in the luminal diameter of the proximal tubules and the luminal surface of the collecting ducts. Most pronounced alterations in the luminal diameter of the distal tubules were observed 3 days, 4 and 6 weeks after the poisoning.