Effects of nitric oxide and cGMP on inhibin A and inhibin subunit mRNA levels from cultured rat granulosa cells.

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.

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. DESIGN: Basic research study. SETTING: University research laboratory. ANIMAL(S): Estrogen-treated immature Sprague-Dawley female rats from which primary cell culture of granulosa cells was obtained. INTERVENTION(S): Functionally immature rat granulosa cells were incubated for 48 hours with media alone, FSH, or FSH plus YC-1, a specific activator of sGC. MAIN OUTCOME MEASURE(S): Expression of sGC alpha and beta subunits was determined by immunoblot analysis. Media concentrations of E2, cAMP, and cGMP were measured by radioimmunoassays. RESULT(S): 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. CONCLUSION(S): 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.

Services provided by volunteer psychiatrists after 9/11 at the New York City family assistance center: September 12-November 20, 2001.

OBJECTIVE: To characterize the experience of volunteer disaster psychiatrists who provided pro bono psychiatric services to 9/11 survivors in New York City, from September 12, 2001 to November 20, 2001. METHOD: Disaster Psychiatry Outreach (DPO) is a non-profit organization founded in 1998 to provide volunteer psychiatric care to people affected by disasters and to promote education and research in support of this mission. Data for this study were collected from one-page clinical encounter forms completed by 268 DPO psychiatrists for 2 months after 9/11 concerning 848 patients served by the DPO 9/11 response program at the New York City Family Assistance Center. RESULTS: In this endeavor, 268 psychiatrist volunteers evaluated 848 individuals and provided appropriate interventions. The most commonly recorded clinical impressions indicated stress-related and adjustment disorders, but other conditions such as bereavement, major depression, and substance abuse/dependence were also observed. Free samples were available for one sedative and one anxiolytic agent; not surprisingly, these were the most commonly prescribed medications. Nearly half of those evaluated received psychotropic medications. CONCLUSIONS: In the acute aftermath of the attacks of September 11, 2001, volunteer psychiatrists were able to provide services in a disaster response setting, in which they were co-located with other disaster responders. These services included psychiatric assessment, provision of medication, psychological first aid, and referrals for ongoing care. Although systematic diagnoses could not be confirmed, the fact that most patients were perceived to have a psychiatric diagnosis and a substantial proportion received psychotropic medication suggests potential specific roles for psychiatrists that are unique and different from roles of other mental health professionals in the early post-disaster setting. In addition to further characterizing post-disaster mental health needs and patterns of service provision, future research should focus on the short- and long-term effects of psychiatric interventions, such as providing acute psychotropic medication services and assessing the effectiveness of traditional acute post-disaster interventions including crisis counseling and psychological first aid.

Roles of cyclic GMP in modulating ovarian functions.

The production of a viable oocyte is dependent upon the critical influences of gonadotrophins on follicular development, granulosa cell maturation, ovulation, and luteinization. While the effects of LH and FSH are due in large part to cyclic AMP-dependent signalling mechanisms, it is clear that a number of other factors modulate the actions of gonadotrophins on the ovary via activation of alternative signalling pathways. In this regard, recent studies indicate that the second messenger guanosine 3',5'-cyclic monophosphate (cGMP) mediates a wide range of influences on the ovary. Nitric oxide (NO) is a major regulator of cGMP production via its action on soluble guanylyl cyclase, while natriuretic peptides activate receptors with intrinsic guanylyl cyclase activities. In addition, other factors known to influence ovarian functions are now recognized to act via NO/cGMP pathways. This report will review these previous findings and present new data demonstrating the inhibitory influence of cGMP on cAMP-stimulated LH receptor expression in cultured granulosa cells.