Abstract
Clock hour independent groups of young female rats received a series of 3 alternate day intraarticular injections of methylprednisolone acetate. All rats lost body weight, but the change was minimal when the injections were given in the late afternoon (-30.8 g) vs. the night (-42.4 g, P < .02). Methylprednisolone acetate, which was designed to be locally active in joint spaces, can probably be absorbed into the circulation. The rate of absorption appeared to be subject to circadian control.