Testosterone secreted by:-

LEYDIG CELLS: Testosterone is secreted by Leydig cells located in interstitium of testis. It is essential for growth & division of testicular germinal cells, which is 1st stage in forming sperm. L.H secreted by anterior pituitary gland, stimulates Leydig cell to secrete testosterone. Seoli cells: FSH secreted by anterior pituitary gland, stimulates Seoli cells This stimulation causes conversion of spermatids to sperm (spermiogenesis) Without this stimulation, spermiogenesis do not occur. Secrete inhibin, Mullerian inhibiting substance Forms blood testes barrier Gonadotropic cells: These cells are present in anterior pituitary gland which secrete both FSH & L.H under the influence of GnRH. Acidophilic cells: Somatotrophs in anterior pituitary stain strongly with acid dyes so they are called acidophil cells. These secrete growth hormone, which stimulates lipolysis, inhibits action of insulin on carbohydrate & lipid metabolism.