Premium
Stimulation of Luteinizing Hormone‐Beta Messenger Ribonucleic Acid and Post‐Translational Modification of Luteinizing Hormone Isoforms by Second Messengers Mediating the Action of Gonadotrophin‐Releasing Hormone
Author(s) -
Leigh A. J.,
Wilson C. A.,
Edger M. J.,
Tipping K. E.,
Patel M.,
Chapman A. J.,
Whitehead S. A.
Publication year - 1991
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/j.1365-2826.1991.tb00325.x
Subject(s) - medicine , gonadotropic cell , endocrinology , second messenger system , luteinizing hormone , stimulation , pituitary gland , anterior pituitary , hormone , endocrine gland , messenger rna , gene isoform , biology , chemistry , receptor , biochemistry , gene
Several second messenger systems have been implicated in mediating the action of gonadotrophin‐releasing hormone on the pituitary gonadotrophs and numerous studies have shown that activation of these systems induces luteinizing hormone (LH) secretion. However, it is not known how gonadotrophin‐releasing hormone or the second messenger systems induce de novo LH biosynthesis and post‐translational modification of the hormone. In these experiments hemipituitary glands have been perifused with drugs which activate second messengers or stimulate protein kinase C directly. The LH secretory responses have been correlated with measurements of common a and LHβ mRNA and the molecular species of LH which were present in the pituitary perifusate after exposure to the drugs. Gonadotrophin‐releasing hormone (50 ng/ml, 42 nM), with and without the presence of extracellular Ca 2+ , the Ca 2+ ionophore, A23187 (10 μM), and phorbol 12‐myristate (1 μM) all stimulated an increase in LHβ mRNA compared with controls and the appearance of a different isoform of LH to that found stored in and released from the unstimulated pituitary gland. Phospholipase C was without effect on LHβ mRNA levels and showed minimal efficacy in inducing the appearance of the different LH isoform.