Mechanisms of Hypothalamic-Pituitary-Gonadal Disruption in Polycystic Ovarian Syndrome

Barontini, Marta; Garcia-Rudaz, M. C.; Veldhuis, Johannes D.

doi:10.1016/s0188-4409(01)00325-3

Cited by 57 publications

(30 citation statements)

References 109 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Several studies have confirmed an increase in LH levels with normal to suppressed levels of FSH in PCOS compared with expected gonadotrophin output in healthy women during the follicular phase of the menstrual cycle [Barontini et al, 2001]. These findings have led to the notion that an elevated LH/FSH ratio is a neuroendocrine hallmark of PCOS.…”

Section: Introductionmentioning

confidence: 80%

“…In women, polycystic ovarian syndrome (PCOS) is characterized by reproductive manifestations that include anovulation, hyperandrogenism, reduced fertility, increased fetal wastage and associated metabolic features comprising insulin resistance, dyslipidemia and premature atherosclerosis [Barontini et al, 2001]. Many studies have demonstrated the heterogeneity of this disorder and unveiled multiple additional abnormalities within and outside the hypothalamic-pituitary-ovarian axis.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the circumstances affecting ovarian function during the diagnosis may be different from the conditions prevailing during the study. Therefore, most of the earlier studies on PCOS are based only on endocrine data, without information about the cellular dynamics of the pituitary gland [Barontini et al, 2001;Doi et al, 2005]. As a result, it is helpful to induce ovarian cysts experimentally in order to monitor their development closely [Baravalle et al, 2007;Ortega et al, 2007].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of Pituitary Cell Populations in Rats with Induced Polycystic Ovaries

Francou¹,

Durdos²,

Salvetti³

et al. 2008

Cells Tissues Organs

View full text Add to dashboard Cite

Several hypotheses have been proposed about the pathogenesis of polycystic ovarian syndrome (PCOS), however, the fundamental physiological interactions that initiate the development of follicular cysts have not yet been elucidated. Hence, in this study the proliferation, density and population of gonadotrophs, mammotrophs, somatotrophs and corticotrophs of the pituitary glands of rats with induced follicular cysts have been investigated by 2 experimental models (continuous light exposition and estradiol valerate-treated rats). Specific immunoreactivity associated with follicle-stimulating hormone, luteinizing hormone, prolactin, growth hormone and adrenocorticotropic hormone was evaluated by immunohistochemistry with specific hormone antibodies and proliferation of secretory cells by their colocalization (double-labeling) with proliferating cell nuclear antigen. The results indicate a reduction in the density and proliferation of gonadotrophs in both experimental groups. A reduction in the average density, proliferation and population of lactotrophs and corticotrophs was also observed in estradiol valerate-treated animals. However, no significant differences were found in somatotrophs. The present study contributes to the information about alterations of some cell populations that occur in the pituitary gland of rats with polycystic ovaries, and will enhance our understanding of the pathogenesis of this disease.

show abstract

Section: Introductionmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of Pituitary Cell Populations in Rats with Induced Polycystic Ovaries

Francou¹,

Durdos²,

Salvetti³

et al. 2008

Cells Tissues Organs

View full text Add to dashboard Cite

show abstract

“…ovarian pathologies such as certain ovarian carcinomas (9,10), granulosa cell tumors after ovarian stimulation in treatments of infertility (11) or in the polycystic ovary syndrome (12), rendering this tumor an interesting model for the study of tumor development under hypergonadotropinemia. This experimental ovarian tumor is highly luteinized (luteoma) (4) and hormonally active since it secretes estradiol, progesterone and inhibins (4,5).…”

Section: Introductionmentioning

confidence: 99%

Development of an experimental ovarian tumor: immunocytochemical analysis

Sorianello

Fritz

Beyer

et al. 2002

European Journal of Endocrinology

View full text Add to dashboard Cite

Objective: The aim of the present work was to study whether immunocytochemical parameters present in the normal ovary were altered after tumor development under high gonadotropin levels. Methods: Ovarian tumors (luteoma): castrated female rats had an ovary grafted into the spleen; tumors were left to develop for 1, 2, 3 or 7 months. The presence of apoptotic cells (TUNEL method) and the expression of proliferating cell nuclear antigen (PCNA), gap junction protein (Cx43), steroidogenic acute regulatory protein (StAR), aromatase and synaptosome-associated protein of 25 kDa (SNAP-25) were determined by immunocytochemistry. Some of these findings were confirmed by RT-PCR (Cx43, StAR, SNAP-25). Inhibin subunit mRNAs were investigated by Northern blot. Results: PCNA staining of tumors was mainly found in granulosa cells of transforming follicles and was absent from luteinized follicles. A nearly complete absence of apoptosis was observed. Cx43 was mainly found in follicles, while it was very weakly expressed or absent in luteinized follicles. StAR protein expression, indicating active steroidogenesis, was demonstrated only in luteinized follicles and in thecal cells, but was absent from granulosa cells. Aromatase immunoreactivity was very intense in granulosa and also present in luteal cells. Membrane-associated and cytoplasmic SNAP-25 immunostaining was determined in patches of endocrine cells in the follicles, as well as in the luteinized follicles. The expression of mRNAs for Cx43, StAR and SNAP-25 (RT-PCR) and inhibin subunits (Northern blots) were confirmed in 1-, 3-and 7-month-old tumors. Conclusions: These results indicated that luteoma most likely develop from unruptured follicles by hypertrophy and proliferation of follicular cells. Circulating gonadotropins seem to play a fundamental role in maintaining the expression of proteins typically expressed in normal ovary, while avoiding apoptosis in this tissue.

show abstract

“…In addition, it is thought that accelerated gonadotropin releasing hormone (GnRH) pulse activity results in an exaggerated release of luteinizing hormone (LH) 21 . Even a mild, chronic elevation in LH can blunt the effect of the hormone surge, leading to anovulation.…”

Section: Fig 2: the Flow Chart Above Detailsmentioning

confidence: 99%

Untitled

2012

IJPSR

View full text Add to dashboard Cite

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women. PCOS varies from a mild menstrual disorder to severe disturbance of reproductive and metabolic functions. Statins, 3-hydroxy-3-methyl-glutarylCoA (HMG-CoA) reductase inhibitors with intrinsic antioxidant properties, exert profound and broad-reaching effects on various types of tissues. By blocking an early step of the mevalonate pathway, statins inhibit proliferation of several cell types including vascular smooth muscles, hepatocytes, and several neoplastic cell lines. The pleiotropic effects of statins may be due to inhibition of cholesterol synthesis. Some common treatments lifestyle changes, insulin-sensitizing agents.

show abstract

Mechanisms of Hypothalamic-Pituitary-Gonadal Disruption in Polycystic Ovarian Syndrome

Cited by 57 publications

References 109 publications

Characterization of Pituitary Cell Populations in Rats with Induced Polycystic Ovaries

Characterization of Pituitary Cell Populations in Rats with Induced Polycystic Ovaries

Development of an experimental ovarian tumor: immunocytochemical analysis

Untitled

Contact Info

Product

Resources

About