Chen YHJ, Tafoya M, Ngo A, LaPolt PS. Effects of nitric oxide and cGMP on inhibin A and inhibin subunit mRNA levels from cultured rat granulosa cells.
Fertil Steril 2003;
79 Suppl 1:687-93. [PMID:
12620478 DOI:
10.1016/s0015-0282(02)04823-9]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE
To determine the effects of nitric oxide (NO) and cGMP on inhibin A and inhibin subunit mRNA levels from cultured rat granulosa cells.
DESIGN
Basic research study.
SETTING
University research laboratory.
ANIMAL(S)
Primary cell culture of granulosa cells obtained from estrogen-treated, immature Sprague-Dawley female rats.
INTERVENTION(S)
Functionally immature rat granulosa cells were incubated for 48 hours with media alone; FSH; forskolin; the NO generator DETA/NO; an inhibitor of soluble guanylyl cyclase (ODQ); and/or a cell-permeable cGMP analog.
MAIN OUTCOME MEASURE(S)
Media concentrations of inhibin A were measured by solid-phase immunosorbent assay. Inhibin alpha and betaA subunit mRNA levels were determined by Northern and slot blot analyses.
RESULT(S)
Whereas FSH caused a 20-fold increase in inhibin A levels compared with untreated granulosa cells, the NO generator DETA/NO significantly inhibited FSH-stimulated inhibin A concentrations. Similarly, cotreatment with FSH plus dibutyryl cGMP significantly attenuated inhibin A concentrations, compared with those in cells treated with FSH alone. Incubation with forskolin (FSK) stimulated inhibin A levels sevenfold, whereas cotreatment with FSK plus DETA/NO or FSK plus dibutyryl cGMP effectively decreased inhibin A concentrations. The effects of NO on inhibin A levels were not prevented by cotreatment with an inhibitor of soluble guanylyl cyclase. In addition, there was no influence of DETA/NO or dibutyryl cGMP on inhibin subunit mRNA levels.
CONCLUSION(S)
These findings indicate that NO and cGMP can attenuate inhibin A concentrations through actions at one or more post-FSH receptor sites. These influences may reflect inhibition of inhibin A secretion, rather than gene expression and protein synthesis. In addition, NO decreases inhibin A concentrations through both cGMP-dependent and -independent pathways. These results suggest local roles for NO and cGMP in the regulation of granulosa cell function.
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