ABSTRACT
The present study was conducted on buffalo foetuses (n=19) ranging from 7.4 (62 days) to 108 cm (317 days) curved crown rump length (CVRL) to study the distribution of phosphatases and oxidoreductases in thyroid gland during prenatal development. A progressive increase in phosphatase activity from 12.50 cm CVRL (85 days) to 41 cm CVRL (166 days) was observed around the blood vessels in the developing thyroid. Mild activity of Succinate dehydrogenase (SDH) was observed at 13.50 cm CVRL (89 days) whereas Lactate Dehydrogenase (LDH) activity was absent at this stage. SDH activity was correlated with mitochondrial localization in developing thyroid. Weak to moderate LDH activity was observed at 56 cm CVRL (200 days) suggesting the presence of glycolytic pathway in developing thyroid. Mild to moderate Reduced Nicotinamide Adenine Dinucleotide diaphorase (NADH-diaphorase) and Reduced Nicotinamide Adenine Dinucleotide Phosphate Diaphorase (NADPH-diaphorase) was noticed in the follicular cells and interfollicular spaces of the thyroid gland at 12.50 cm CVRL (85 days) which progressively increased with gestational age and became intense at 56 cm CVRL (200 days) indicating increase in metabolic activity.