Histochemical study of the rat anterior pituitary LH-gonadotroph after administration of luteinizing hormone releasing hormone (LH-RH).
The aim of this study was to identify the LH-gonadotroph, aided by histochemical demonstrations of adenylate cyclase and acid phosphatase activities in 60-day-old male rats, after a single 100 micrograms injection of luteinizing hormone-releasing hormone (LH-RH). The results obtained are as follows: 1) Separation of the lysosomes from the large secretion granules in the LH-gonadotroph was accomplished in order to demonstrate acid phosphatase, the marker enzyme of lysosomes. 2) The large granules in the LH-gonadotroph decreased remarkably in number within 5 min after LH-RH injection. 3) A marked and prolonged increase in adenylate cyclase activity was observed on the plasma membrane of the LH-gonadotroph after LH-RH injection; this increase continued up to 30 min. 4) At 60 min after LH-RH injection the small secretion granules began to decrease in number. 5) Losing the large granules due to the LH-RH treatment, the LH-gonadotroph resembled the FSH-gonadotroph. From these observations it appears that the FSH-gonadotroph is an immature or storage state LH-gonadotroph and that it changes from an LH-gonadotroph into an FSH-gonadotroph on the loss of its large secretion granules.
D000135:Acid Phosphatase / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage*; D006651:Histocytochemistry; D007275:Injections, Intravenous; D007986:Luteinizing Hormone / Q000032:analysis* / Q000378:metabolism; D008297:Male; D010903:Pituitary Gland, Anterior / Q000201:enzymology* / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains
D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D000135:Acid Phosphatase; D000262:Adenylyl Cyclases