Effect of estrogen on the melanin content of liver of toad (Bufo melanostictus)

Estrogen injection (1 microgram/g of body weight, single injection) reduced significantly the melanin content of liver of both male and female toads. Estrogen at the dose of 0.1 microgram/g did not cause any change in the amount of melanin in liver of toads. With higher doses of the hormone (2 microgram/g, single injection) the melanin content of liver tended to decrease further but the differences was not statistically significant in comparison with the results of injection of 1 microgram of estrogen per g of body weight. The reduction in the amount of melanin in liver of both male and female toads was noticed within 24 h of injection and was contained up to the 7th day of experiment. It was also found that the maximum fall in the amount of melanin in liver took place within 3 days.