Effect of thyroxine and thiourea on cholesterol total lipid and glycogen contents of brain of Singi fish ( Heteropneustes fossilis bloch)

Three consecutive days injections of thyroxine of different doses (1, 2 and 4 μg/g of body weight) caused significant increase in cholesterol content of cerebrum of Singi fish at 25°C in comparison to the control. The cholesterol content of cerebellum, midbrain and medulla oblongata was enhanced significantly with higher doses of 2 and 4 μg of thyroxine per g of body weight. The lipid and glycogen contents of whole brain were also found to increase with different doses of thyroxine after three consecutive days injections. These cellular constituents decreased with hypothyroid condition induced by thiourea treatment. The results indicate the thyroid hormonal regulation of lipid and carbohydrate metabolism in brain of Singi fish.