Objective:To investigate the impact of thyroid hormones on testosterone secretion in rat Leydig cells Methods:The rat′s Leydig cells were cultured and exposed to a series of concentrations of T 3 (0 μg/ml, 0 01 μg/ml, 0 1 μg/ml, 1 and 10 μg/ml) Basal and challenged testosterone levels were measured The distinction of Leydig cells′ secretion in vitro was evaluated between different thyroid function groups Results:There were no changes in testosterone levels when normal Leydig cells were exposed...