Abstract
The possible roles of adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) and of polyamines on the early effect of prolactin (PRL) on lactose biosynthesis have been investigated in cultured mammary gland explants derived from mice 12-14 days pregnant. Elevated cAMP concentrations impaired the PRL stimulation of [3H]glucose incorporation into lactose. Adding dibutyryl cAMP (0.1-0.5 mM) or phosphodiesterase inhibitors [methyl isobutylxanthine (0.1-0.5 mM) or theophylline (0.5-5.0 mM)] to the culture medium abolished the PRL response. The addition of 8-bromo cGMP (0.5 mM) with or without 1.0 mM spermidine had no effect on the PRL stimulation of lactose synthesis. By itself, 1.0 mM spermidine consistently produces a small but significant PRL-like stimulation of lactose synthesis in this system. Ongoing polyamine metabolism appears to be necessary for the PRL effect on lactose synthesis because 100 microM methylglyoxal bis(guanyl hydrazone), an inhibitor of S-adenosyl methionine decarboxylase, abolished the PRL response. alpha-Difluoromethylornithine, an inhibitor of ornithine decarboxylase activity, at concentrations from 1.0 to 10 mM had no effect on the PRL stimulation of lactose synthesis.
References
Sep 1, 1978·Hormone and Metabolic Research = Hormon- Und Stoffwechselforschung = Hormones Et Métabolisme·R F Loizzi
Jan 1, 1978·Biochemical Pharmacology·A E Pegg, S M McGill
Oct 29, 1979·Biochemical and Biophysical Research Communications·F F Bolander, Y J Topper
May 5, 1975·Biochimica Et Biophysica Acta·R F LoizziS L Bonting
Jun 1, 1975·Journal of Dairy Science·S L Louis, R L Baldwin
Apr 1, 1976·Proceedings of the Society for Experimental Biology and Medicine·J A Rillema
Feb 1, 1977·Endocrinology·J A RillemaJ A Mulder
Jul 1, 1988·Proceedings of the Society for Experimental Biology and Medicine·C A Oppat, J A Rillema
Oct 17, 1985·Biochimica Et Biophysica Acta·A E PeggL Persson
Aug 6, 1973·Biochemical and Biophysical Research Communications·M Sapag-Hagar, A L Greenbaum
Nov 1, 1972·The Biochemical Journal·D H Russell, T A McVicker
Jun 1, 1973·Endocrinology·J A Rillema
Aug 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·G B SilbersteinC W Daniel
Apr 1, 1980·Proceedings of the National Academy of Sciences of the United States of America·J W Perry, T Oka
Apr 1, 1982·Hormone and Metabolic Research = Hormon- Und Stoffwechselforschung = Hormones Et Métabolisme·J A Rillema, L Y Wing
Oct 1, 1983·Proceedings of the Society for Experimental Biology and Medicine·J A Rillema, C M Cameron
Jan 1, 1980·Annual Review of Physiology·R P Shiu, H G Friesen
Aug 1, 1981·Clinical Pharmacology and Therapeutics·K D HaegeleJ Koch-Weser
Oct 25, 1957·Science·J J ELIAS