Prednisolone effects upon body and organ weights, water intake, and several behaviors

Various behavioral sequelae have been noted in patients receiving prolonged, high-dose glucocorticoid therapy. The present study assayed several behavioral dimensions of rats receiving daily intramuscular injections of the synthetic glucocorticoid, prednisolone. Specifically, assessments of water intake, nociception, locomotion, and the grasping responses were conducted; measures of gonadal, adrenal, and total body weights were also taken. Twelve daily injections were given to four groups (N = 6/group) of immature male rats with each group receiving a different dose of drugs (0.0, 8.0, 16.0, 32.0 mg/kg). Prednisolone generally suppressed home-cage water intake, and latencies to hind paw-lick in the hot-plate assay. Measures of wheel running and the grasping response were generally enhanced. Absolute gonadal and adrenal weights as well as total body weights were decreased. Relative organ weights suggested that daily prednisolone treatments had produced suppression of the pituitary-adrenal axis. It was concluded that prednisolone is active in these assays and that such measures may be useful in studies of drug interaction with this agent.