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Ovarian Physiology (ovarian + physiology)
Selected AbstractsMelatonin: therapeutic and clinical utilizationINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2007A. Altun Summary Melatonin, acting through melatonin receptors, is involved in numerous physiological processes including circadian entrainment, blood pressure regulation, oncogenesis, retinal physiology, seasonal reproduction, ovarian physiology, immune function and most recently in inducing osteoblast differentiation. Moreover, melatonin was proved to be a potent-free radical scavenger and a broad-spectrum antioxidant. More research is required into the effects of therapeutically modulating the melatoninergic system on circadian haemodynamics and rhythm under varying physiopathological conditions and the possible impact on morbidity and mortality in humans. [source] Temporal and Spatial Distribution of the Cannabinoid Receptors (CB1, CB2) and Fatty Acid Amide Hydroxylase in the Rat OvaryTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2010P. Bagavandoss Abstract Although the effects of ,9 -tetrahydrocannabinol (THC) on ovarian physiology have been known for many decades, its mechanism of action in the rat ovary remains poorly understood. The effects of THC and endocannabinoids on many cell types appear to be mediated through the G-protein-coupled CB1 and CB2 receptors. Evidence also suggests that the concentration of the endocannabinoid anandamide is regulated by cellular fatty acid amide hydrolase (FAAH). Therefore, we examined the rat ovary for the presence of CB1 and CB2 receptors and FAAH. The CB1 receptor was present in the ovarian surface epithelium (OSE), the granulosa cells of antral follicles, and the luteal cells of functional corpus luteum (CL). The granulosa cells of small preantral follicles, however, did not express the CB1 receptor. Western analysis also demonstrated the presence of a CB1 receptor. In both preantral and antral follicles, the CB2 receptor was detected only in the oocytes. In the functional CL, the CB2 receptor was detected in the luteal cells. FAAH was codistributed with CB2 receptor in both oocytes and luteal cells. FAAH was also present in the OSE, subepithelial cords of the tunica albuginea (TA) below the OSE, and in cells adjacent to developing preantral follicles. Western analysis also demonstrated the presence of FAAH in oocytes of both preantral and antral follicles. Our observations provide potential explanation for the effects of THC on steroidogenesis in the rat ovary observed by earlier investigators and a role for FAAH in the regulation of ovarian anandamide. Anat Rec 293:1425,1432, 2010. © 2010 Wiley-Liss, Inc. [source] Actions of glucocorticoid and their regulatory mechanisms in the ovaryANIMAL SCIENCE JOURNAL, Issue 2 2007Masafumi TETSUKA ABSTRACT Glucocorticoid (G) directly modulates ovarian functions through binding to G receptor. The actions of G are both agonistic and antagonistic depending on the developmental stage of follicles and corpora lutea (CL). During follicular maturation, G suppresses follicular differentiation by downregulating expression of P450 aromatase and luteinizing hormone (LH) receptor in granulosa cells. During ovulation, G protects the ovulatory follicle from inflammatory damage and promotes luteinization, ensuring a smooth transition of the follicle to CL. Throughout life the ovary is exposed to periodic and sporadic waves of G. The Ovary appears to cope with this situation by locally modulating levels of active G. The primary regulatory mechanism consists of two isoforms of 11,-hydroxysteroid dehydrogenase (11,HSD) that catalyze conversion between active and inactive G. During follicular maturation the levels of active G are suppressed by the dehydrogenase activity of 11,HSD, whereas during the ovulatory process, levels of active G are further increased by the oxo-reductase activity of 11,HSD. The expression of these enzymes is under the control of gonadotrpins and local regulatory factors such as cytokines, allowing the mechanism to act in coordination with major reproductive events. Thus the G system is an integral part of ovarian physiology, which ensures that the ovary experiences only beneficial effects of G. [source] Anti-Müllerian hormone (AMH) in female reproduction: is measurement of circulating AMH a useful tool?CLINICAL ENDOCRINOLOGY, Issue 6 2006A. La Marca Summary Anti-Müllerian hormone (AMH) is a dimeric glycoprotein, a member of the transforming growth factor (TGF) superfamily. It is produced exclusively in the gonads and is involved in the regulation of follicular growth and development. In the ovary AMH is produced by the granulosa cells of early developing follicles and seems to be able to inhibit the initiation of primordial follicle growth and FSH-induced follicle growth. As AMH is largely expressed throughout folliculogenesis, from the primary follicular stage towards the antral stage, serum levels of AMH may represent both the quantity and quality of the ovarian follicle pool. Compared to other ovarian tests, AMH seems to be the best marker reflecting the decline of reproductive age. AMH measurement could be useful in the prediction of the menopausal transition. It could also be used to predict poor ovarian response and possibly the prognosis of in vitro fertilization (IVF) cycles. AMH has been shown to be a good surrogate marker for polycystic ovary syndrome (PCOS). Finally, its use as a marker for granulosa cell tumours has been proposed. A clearer understanding of its role in ovarian physiology may help clinicians to find a role for AMH measurement in the field of reproductive medicine. [source] |