Effect of luteinizing hormone (LH) and LH-releasing hormone (LHRH) on testosterone production in vivo, in fetal rabbit testis in late gestation.
Plasma and tesicular testosterone were measured by radioimmunoassay in the 29-day-old rabbit fetus receiving an injection of saline solution, LH or LHRH. 30 min following the injection of 5 microgram LH into the umbilical vein, testosterone levels were significantly increased by 287% in the plasma and 293% in the testis, compared with controls receiving saline solution. The injection of 2 microgram of LHRH under the same conditions significantly increased testicular testosterone by 256% and plasma testosterone by 746%. The results show that the fetal rabbit testis, at the end of gestation, is capable of responding to LH stimulation. The hypophysio-testicular axis is apparently functional at this stage of gestation, as shown by the response to LHRH.
D000818:Animals; D005312:Fetal Blood / Q000378:metabolism; D005865:Gestational Age; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D011817:Rabbits; D012636:Secretory Rate / Q000187:drug effects; D013737:Testis / Q000196:embryology / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis* / Q000097:blood
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone