Photic Stress Modulates Cholesterol Content and Oxidative Load of Steroidogenic Organs (Adrenal, Ovary and Testis) of Indian Spotted Finch Lonchura punctulata

Steroidogenic organs such as adrenal gland and gonad are of vital importance in birds, as the adrenal gland regulates stress by modulating the levels of corticosterone, while gonads synthesize gonadal steroids that regulate breeding cycle. Cholesterol content in both adrenal and gonad reflect the physiological status of these organs for stress management and reproduction, respectively. Birds, being photosensitive, experience phototoxicity in the nature due to the rapid urbanization. If photic stress induced by constant dark (DD) and constant light (LL) influences steroidogenesis in terms of cholesterol content and total antioxidant status (TAS%) as a marker of stress was experimentally assessed in Indian spotted finch Lonchura punctulata along with measurement of peripheral corticosterone levels. DD was stressful and, hence, caused decrease of ovary / testis weight and increase of adrenal gland weight, while cholesterol content decreased significantly due to inhibition of steroidogenesis. LL stimulated gonadal function but caused decrease of cholesterol content suggesting active steroidogenesis. TAS% increased under DD and decreased under LL. The phototoxicity, whether in term of DD or LL, was stressful to Indian spotted finch as evident from increased adrenal gland weight and decreased cholesterol content that can be correlated with increased synthesis of corticosterone. It may be concluded that cholesterol content is an important marker of streroidogenic status, and extremes of photoperiod influence cholesterol content, corticosterone level and TAS%.