GOPALA REDDY, A(MAJOR)RAVl KUMAR, PMADHAVA RAO, TANAND KUMAR, AANlL KUMAR, B2018-11-132018-11-132011-07http://krishikosh.egranth.ac.in/handle/1/5810083369THESESABSTRACT: An experimental study was conducted to evaluate the molecular mechanisms of lead and cadmium toxicity and their toxicodynamic interaction, and to evaluate therapeutic potential of N-Acetyl L-cysteine (NAC) against the toxicity in Wstar rats. After an acclimatization period of 2 weeks, rats were randomly divided into 8 groups comprising of 6 rats in each. Group 1 was kept as normal control throughout the experimental period, 2 was given NAC @ 300 mg per kg body weight administered by oral gavage, 3 was given lead (lead acetate @ I000 ppm in feed), 4 was given cadmium (cadmium chloride @ 300 ppm in feed), 5 was given lead + cadmium as per above doses in feed, 6 was given lead + NAC as per above schedule, 7 was given cadmium + NAC as per above schedule, and group 8 was given lead + cadmium + NAC as per above schedule for 3 months. Body weights, haematology (TEC, TLC, Hb, PCV, MCH and MCHC), activity of 6-ALAD and erythrocytic SOD, sero-biochemical parameters (ALT, CPK, troponins, plasma TBARS and serum creatinine), antioxidant profile (GSH, GST, TBARS and protein carbonyls) in liver, kidney, heart, testis and brain, ATPases and tissue lipids in liver and brain, neurotransmitters (Ach and glutamate) in brain, CYP450, glycogen and G6PD in liver, weight of testes, testicular LDH and sperm count, electron microscopy of kidney in cadmium exposed groups and histopathology of liver, kidney, testis and heart were studied. Also, interaction of lead and cadmium with zinc and copper in liver, kidney, heart, testis and brain was assessed. The present study revealed significant alterations in body weights, haematology, sero-biochemical parameters, antioxidant profile, ATPases, tissue lipid profile, neurotransmitter, CYPd50, glycogen, GGPD, weights of testes, testicular LDH, sperm count, and concentration of zinc and copper in toxic control groups 3, 4 and 5 as compared to control and NAC-treated groups. The toxic combination (Pb + Cd) group 5 showed significant alterations in most of the parameters studied as compared to Pb alone and Cd alone administered groups. All the NAC-treated groups revealed significant improvement in all the parameters. The histological studies of liver, kidney, testis and brain revealed marked changes in toxic control groups, while therapeutic groups revealed mild changes or no pathologically significant changes. Groups 1 and 2 were devoid of any alterations. The electron microscopy of kidney revealed marked alterations in kidney architecture in groups 4 and 5, while groups 7 and 8 revealed better architecture. The results of the investigation revealed that lead, cadmium' and their combination induced toxicity to the biological system due to the excess generation of free radicals and impairment of antioxidant defenses. Toxic effects were more pronounced in the group that received a combination of lead and cadmium suggesting positive toxicodynamic interaction. Use of NAC countered the adverse effects of lead and cadmium induced toxicity to a major extent suggesting its antioxidant potential owing to replenishment of tissue pool of GSH. Further, NAC administration reduced the extent of accumulation of lead and cadmium in various tissues.ennullThesis