Activation of soluble guanylyl cyclase inhibits estradiol production and cyclic AMP accumulation from cultured rat granulosa cells.
OBJECTIVE
To demonstrate the expression of soluble guanylyl cyclase (sGC) alpha and beta subunits in rat granulosa cells and determine the effects sGC activation on levels of cyclic GMP (cGMP), E2, and cAMP.


METHODS
Basic research study.


METHODS
University research laboratory.


METHODS
Estrogen-treated immature Sprague-Dawley female rats from which primary cell culture of granulosa cells was obtained.


METHODS
Functionally immature rat granulosa cells were incubated for 48 hours with media alone, FSH, or FSH plus YC-1, a specific activator of sGC.


METHODS
Expression of sGC alpha and beta subunits was determined by immunoblot analysis. Media concentrations of E2, cAMP, and cGMP were measured by radioimmunoassays.


RESULTS
Immunoblot analysis of granulosa cells revealed the expression of sGC alpha and beta subunits. While cGMP accumulation was low in cells incubated with media alone or with FSH, cotreatment with FSH plus YC-1 increased cGMP levels approximately five-fold. Incubation of cells with FSH stimulated E2 production in a dose-dependent manner. However, cotreatment of cells with FSH plus YC-1 significantly decreased E2 concentrations at all doses of FSH tested. Similarly, while FSH increased cAMP accumulation from granulosa cells, cotreatment with YC-1 markedly inhibited FSH-stimulated cAMP levels.


CONCLUSIONS
These findings demonstrate the expression of sGC subunits in rat granulosa cells and indicate that activation of sGC increases cGMP levels, which are associated with inhibition of FSH-stimulated E2 production and cAMP accumulation.
Department of Biological Sciences, California State University, Los Angeles, California 90032, USA.
Michael A
MA
Tafoya
Jean You-Hsin
JY
Chen
Robert L
RL
Stewart
Philip S
PS
Lapolt
D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004357:Drug Synergism; D004789:Enzyme Activation / Q000502:physiology; D020536:Enzyme Activators / Q000494:pharmacology; D004958:Estradiol / Q000096:biosynthesis*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006107:Granulosa Cells / Q000201:enzymology / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000737:chemistry / Q000378:metabolism*; D006728:Hormones / Q000494:pharmacology; D015151:Immunoblotting; D007191:Indazoles / Q000494:pharmacology; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility
D020536:Enzyme Activators; D006728:Hormones; D007191:Indazoles; D007527:Isoenzymes; C090937:3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP; D006162:Guanylate Cyclase; D006152:Cyclic GMP