Testis is not the source for which of the following?

Ref:1. Peil GK. Male reproductive system, in: Textbook of medical physiology. 2nd eel. Ahuja publishing house. 2011; 54: 448-449W F Gartong. The Gonads: Development & Function of the Reproductive System. In: Review of Medical Physiology. 21st eel. California: McGraw-Hill Companies; 2003.Explanation:Leydig cell mainly secretes testosterone.Dehydroepiandrosterone. Androstenodioneare also secreted from leydig cell.Dihydrotestosterone is a testosterone metabolite. It induces the formation of male external genitalia and male secondary sex characteristicsLeydig cellsPrimary cells of steroidogenesis; Present in interstitial space between seminiferous tubules; rich in mitochondria <& EPRSecretes testosterone, DHEA, AndrostenodioneActivity is more in- 8-15 week of IUL - hCG; 3-5 months of post natal (infantile testosterone surge); Onset of puberty - maximum; Basal secretion till senescenceSertoli CellFunctions of sertoli cellGerm cell development - structural supportNourishment & growth of spermatidPhagocytosis (residual bodies during maturation)Formation of tubular fluidSupport spermiation - secrete plasminogen activatorEndocrine function- Inhibin. Follistatin -| FSH- Activin - | FSH- MIS (Mullerian Inhibiting Substance) - 8th week of IUL- Estrogen - from androgen by aromataseIt has FSH. testosterone (receptors) sensitivitySecretory functions- Androgen binding Protein (ABP) - binds with DHT. testosterone & transport to epididymis- H- Y antigen - development of gonads and Plasminogen activatorBlood Testis Barrier (BTB)Paracrine effect on leydig cell