Toxicopathology of paraquat herbicide in female Wistar rats.

摘要

Paraquat (PQ) is commonly used in agriculture as a contact herbicide to control the growth of weeds and grasses and is easily accessible to farmers in developing countries. Paraquat is highly toxic to human and is associated with high mortality varying from 35-50%. The main causes for mortality are respiratory and multi organ failure. In this experimental study, twenty four female Wistar rats of 6-7 weeks age were divided into four equal groups. Group-I rats served as control whereas groups-II, III and IV rats were given daily paraquat solution at the dose rate of 10, 15 and 25 mg kg -1 b.wt, respectively, orally by gavage for 28 days. At end of the 2nd week of the experiment, mild diarrhoea, anorexia, polydipsia and reduced locomotional activities were noticed. Hematological observations showed significant decrease in Hb, PCV, TEC and TLC values and biochemical parameters revealed significant increase in AST, ALT and creatinine levels when compared to control group. Gross pathological observations of lungs from all treatment rats showed mild congestion and emphysema. An accidental finding of hydronephrosis was recorded in group-II and atrophy of left kidney and hypertrophy of right kidney was observed in group-III. Few animals from group-IV showed rounded flabby heart. Histopathologically, granular and vacuolar changes were observed in liver and kidneys. Lungs showed prominent congestion and oedema. From the present investigation it was concluded that paraquat toxicity adversely affects general performance, hematological and biochemical parameters in rats. Histopathological changes in liver and kidneys indicated its hepatoxic and nephrotoxic effects.