STUDIES ON RAT-THYROID AFTER ORAL-ADMINISTRATION OF MANCOZEB - MORPHOLOGICAL AND BIOCHEMICAL EVALUATIONS

Mancozeb, an ethylenebisdithiocarbamate (EBDC), has been studied for i ts effects on rat thyroid, Single oral administration of mancozeb at d ifferent concentrations (9600, 12 000, 15 000 and 18 750 mg kg(-1) bod y wt) has derived the oral LD50 value as 15 000 mg kg(-1) body wt, in male rats, Mancozeb at repeated oral doses of 500, 1000 and 1500 mg kg (-1) day(-1) for periods of 30, 90, 180 and 360 days has produced dose -dependent signs of toxicity and death of animals, The fungicide cause d a significant increase in thyroid/body weight ratio and histopatholo gical changes, Reduced levels of thyroid radioiodine (I-125) uptake, s erum protein-bound iodine ((PBI)-I-125), thyroxine (T-4) and reduced a ctivity of thyroid peroxidase (TPO) have also been observed after expo sure to mancozeb, Thus, mancozeb has been shown to produce marked stru ctural and functional changes in thyroid of rats. (C) 1997 by John Wil ey & Sons, Ltd.