PATHOLOGICAL STUDIES ON THE TOXIC EFFECT OF LEAD IN ALBINO RATS

Abstract

The aims of the present study were to evaluate the pathologic lesions and the clinopathologic changes associated with lead acetate (PbAc) toxicosis in male albino rats with special focus on the role of antioxidant and/or apoptosis in the pathogenesis of this toxicosis. Ninety nine mature male Albino rats (110-130 of body weight) were used in this study. The study was divided into 2 experiments (Exps. I, II). Exp. I (Gps. 1, 2, 3, 4 and 5) was used to study the pathologic and clinicopathologic changes associated with the acute and chronic toxicosis with lead actetate. Rats of gps. 1, 2, 3, and 4 were intubated daily with PbAc at doses of 700, 1000, 200, or 400 mg/ Kg body weight respectively for 7 days (gps 1 and 2) or 90 days (gps. 3 and 4). Rats ofGp. 5 were kept as a control group. Exp. II (Gps. 6, 7, 8 and 9) was used to study the possible protective effect of zinc sulphate against the intoxication with PbAc. Rats of gps. 6 and 7 were intubated with lead acetate 500 mg/kg body weight by stomach tube daily for ten days. Simultaneously with the PbAc, rats of gp. 7 received zinc sulphate (250 mg/L drinking water) daily for 10 days. Rats of gp. 8 received only zinc sulphate (250 mg/L drinking water) daily for 10 days, while, rats of gp. 9 were kept as a negative control group. Clinical signs of the acutely intoxicated rats included drowsiness, anorexia, lethargy, weight loss, and polyuria. The most characteristic signs of the chronically intoxicated rats were loss of appetite, weight loss, ruffled hair, and reluctance to move. No significant clinical signs were observed in control rats. In exp. II rats of gps. 6 and 7 experienced anorexia, lethargy, and mild diarrhea. No mortalities were recorded in exp. II. No significant clinical signs were observed in rats of gps. 8 and 9. The pathologic studies revealed that the target organs of the acute and chronic intoxication with the PbAc were brain, liver, testes and kidneys. On the other hands, other examined organs (lung, heart, spleen, and intestines) were less affected and did not show significant lesions. Renal changes in gps 1 and 2 were