testicular hormone, any androgenic steroid hormone secreted by the Leydig cells in the interstitial tissues of the male gonads. Testosterone is the principal hormone secreted by the cells, which also secrete estrogen, the female sex hormone. Testosterone may be converted into estrogen and other steroid hormones, such as dihydrotestosterone, in certain tissues. The secretion of testicular hormones is controlled by luteinizing hormone and follicle-stimulating hormone, both secreted by the anterior pituitary gland.
