Objective:To observe the response of Leydig cells isolated by Percoll to the stimulation of human Chorionic Gonadotropin. Methods:Leydig cells were isolated and purified by a discontinuous Percoll gradient of 20%~80% and then cultured for 5 days. human Choronic Gonadotropin was given in different time and in different dosage. Testosterone was measured. Results:The purity of Leydig cells was 80%~85%. Testosterone decreased with time going. The peak of testosterone stimulated by hCG was in the first and secon...