It is recognised that ovarian factors, including steroid and protein hormones, are critical in the feedback regulation of pituitary gonadotropins; however, their individual contributions are less defined. The aim of this study was to explore the reciprocal relationships between ovarian and pituitary hormones across the normal ovulatory menstrual cycle as women age. FSH, LH, oestradiol, progeste...

The present study was undertaken to identify the mechanisms underlying the effect of insulin-like growth factor (IGF-I) on LH receptor in rat granulosa cells. Treatment with FSH, as expected, produced a substantial increase in LH receptor messenger RNA (mRNA) level, and concurrent treatment with increasing concentrations of IGF-I brought about dose-dependent increases in FSH-induced LH receptor...

In the process of oocyte maturation, gonadotrophins are believed as main stimulators for oocyte meiosis resumption. However, which gonadotrophin (i.e. FSH or LH) is the key hormone in this process is still unknown. This study indicated a close relationship between LH and FSH on activating meiotic maturation of oocyte in vitro. FSH efficiently induced oocyte meiosis at concentration of 50 IU/L, ...

In two experiments with ovariectomized ewes, the plasma levels of LH and FSH were measured following passive immunization against LH-RH. The pulsatile secretion of LH was inhibited and the levels of the hormone fell quickly and were undetectable within 24 h. The levels of FSH fell more slowly and were always detectable. In the second of the experiments, pulses of LH of normal amplitude were re-...

Results from a multicenter evaluation of two new enzyme-linked immunosorbent assays [Enzymun-Test for follitropin (FSH) and lutropin (LH)] are presented and compared with results from 11 other commercial immunoassays, radioactive as well as nonradioactive. Enzymun-Test FSH and LH assays are suitable for automated systems and manual applications. The tests were reproducible (CV less than 5%), hi...

The aim of this study was to determine if follicle stimulating hormone receptor and luteinizing hormone receptor (FSH-R and LH-R) expression is altered on granulosa cells (GC) of women with low oestradiol responses to FSH. Cells were obtained from mature follicles (>17 mm) following controlled ovarian stimulation. For comparison, chinese hamster ovary (CHO) cells transfected with FSH-R or LH-R ...

Background: With the recent development of recombinant gonadotropins (FSH and LH), it has become possible to further adjust the stimulation protocol according to the expected needs of the patient. In this respect, the possible beneficial role of exogenous LH activity supplementation for stimulated ART cycles has received increasing attention. According to the two-cell, two- gonadotropin theory,...

Polycystic Ovary Syndrome (PCOS) is a widespread endocrine-reproductive-metabolic condition with severe implications for females’ health. The role of four essential parameters on PCOS, including Human Leukocyte Antigens (HLA) represented by the HLA-B*0702 allele, anti-Follicle Stimulating Hormone (anti-FSH) antibodies, anti-Luteinizing (anti-LH) and vitamin D3 was investigated. A total 100 samp...

Until now, clinicians have been relying solely on LH activity-dependent triggering of final oocyte maturation and thus taken it for granted that the natural midcycle FSH surge is biologically redundant. However, it is time to question this paradigm. Evidence from clinical studies hint that in a yet-to-be-defined subset of patients, dual LH and FSH surge is advantageous compared with LH-only sur...

Previous studies indicated that there is a separate hypothalamic control of follicle-stimulating hormone (FSH) release distinct from that of luteinizing hormone (LH). An FSH-releasing factor (FSHRF) was purified from rat and sheep hypothalami, but has not been isolated. We hypothesized that FSHRF might be an analogue of mammalian luteinizing hormone-releasing hormone (m-LHRH) and evaluated the ...