Cyclic GMP stimulates inositol phosphate production in cultured pituitary cells: possible implication to signal transduction.
Addition of the stable and permeable analog 8-bromo cyclic GMP (8-BR-cGMP) to myo-[2-3H]inositol prelabeled cultured rat pituitary cells results in enhanced formation of [3H]-myo-inositol monophosphate (IP1). The stimulatory effect of the cyclic nucleotide analog is additive to the effect of Li+, which accumulates IP1 via inhibition of inositol 1-monophosphatase, and also to the effect of gonadotropin releasing hormone (GnRH) which stimulates the formation of IP1, as well as that of inositol 1,4-bisphosphate (IP2) and inositol 1,4,5-trisphosphate (IP3) via enhanced hydrolysis of polyphosphoinositides. Many Ca2(+)-mobilizing hormones acting via phosphoinosite turnover also stimulate cGMP formation. The cyclic nucleotide might then serve as a modulator by further hydrolysis of phosphoinositides needed for protein kinase C activation.
Naor
Z
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Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.
D000818:Animals; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007295:Inositol Phosphates / Q000378:metabolism*; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D015398:Signal Transduction / Q000187:drug effects*
D007295:Inositol Phosphates; C016276:8-bromocyclic GMP; D007987:Gonadotropin-Releasing Hormone; D008094:Lithium; D006152:Cyclic GMP