Glucocorticoid-Induced Alterations in the Reproductive Functions of Male Mus terricolor , the Indian Pygmy Field Mouse

Abstract

The Indian pygmy field mouse, Mus terricolor , a wild rodent has to face many stressors in the environment such as unpredictable harsh weather, non-static habitats, food shortage, water scarcity, social pressure, risk of predators and parasites, etc. Glucocorticoids are known to suppress reproductive functions during the stressful situations in many rodents. No report till date exists demonstrating the effects of stress on the reproduction in male M. terricolor , a tropical, wild, nocturnal, short day breeder. To replicate stress-like situation under experimental condition, dexamethasone (60μg/100g body weight) treatment was given to this tiny rodent during the Reproductively Active Phase (RAP) of its breeding cycle. Administration of dexamethasone led to significant reductions in the weights of gonad and accessory sex organs, which were accompanied by significant reductions in the biochemical constituents viz., epididymal sialic acid and seminal vesicular fructose. The levels of plasma testosterone also decreased significantly while there was a significant increase in the gonadal cholesterol after the treatment. Histological observations revealed inhibitory effects of dexamethasone on the reproductive tissues. It is, therefore, suggested that the stressful condition due to exogenous administration of glucocorticoid suppresses the reproductive functions of M. terricolor .