Rat Fshb (Follitropin subunit beta) ELISA Kit

Context: A polymorphism in the FSHB promoter (-211G -> T, rs10835638) was found to be associated with decreased FSH, elevated LH, reduced testosterone, and oligozoospermia in males. Although FSH is pivotal for ovarian function, no data on consequences of FSHB -211G -> T are available in females. Objective: We studied the effects of FSHB -211G -> T on the hypothalamic- pituitary-ovarian axis in women. Design and Setting: In a university-based in vitro fertilization unit, women undergoing standardized diagnostics were genotyped and compared with a fertile control group. Patients: The study group consisted of 365 thoroughly characterized women with normal menstrual cycle intervals and proven ovulation, with predominantly male-factor infertility. The independently recruited control group included 438 women with proven fertility and no history of abortions. Main Outcome Measures: Distribution of alleles and genotypes were compared between the study group and controls. In the study group, associations of endocrine parameters with FSHB -211G -> T were assessed. Results: Allele and genotype frequencies were not significantly different between the study population and controls (T-allele: 14.4 vs. 16.6%; TT-homozygotes: 2.5 vs. 3.2%). The FSHB -211G -> T TT-genotype was strongly associated with elevated FSH (TT-homozygosity effect 2.05 U/liter, P = 0.003). LH increased with the number of T-alleles (1.30 U/liter per T-allele, P < 0.001). Additionally, FSHB -211G -> T was associated with reduced progesterone (-1.96 ng/ml per T-allele, P = 0.047). Conclusions: This is a report on phenotypic consequences of FSHB -211G -> T on the hypothalamic-pituitary-ovarian axis in women. The findings, partially contradictory to those in men, point to a gender-specific compensatory mechanism of gonadotropin secretion, probably involving progesterone. (J Clin Endocrinol Metab 98: E82-E86, 2013)

The activin/inhibin system regulates follicle-stimulating hormone (FSH) synthesis and release by pituitary gonadotrope cells in mammals. In vitro cell line data suggest that activins stimulate FSH -subunit (Fshb) transcription via complexes containing the receptor-regulated SMAD proteins SMAD2 and SMAD3. Here, we used a Cre-loxP approach to determine the necessity for SMAD2 and/or SMAD3 in FSH synthesis in vivo. Surprisingly, mice with conditional mutations in both Smad2 and Smad3 specifically in gonadotrope cells are fertile and produce FSH at quantitatively normal levels. Notably, however, we discovered that the recombined Smad3 allele produces a transcript that encodes the entirety of the SMAD3 C-terminal Mad homology 2 (MH2) domain. This protein behaves similarly to full-length SMAD3 in Fshb transcriptional assays. As the truncated protein lacks the N-terminal Mad homology 1 (MH1) domain, these results show that SMAD3 DNA-binding activity as well as SMAD2 are dispensable for normal FSH synthesis in vivo. Furthermore, the observation that deletion of proximal exons does not remove all SMAD3 function may facilitate interpretation of divergent phenotypes previously described in different Smad3 knockout mouse lines.Fortin, J., Boehm, U., Weinstein, M. B., Graff, J. M., Bernard, D. J. Follicle-stimulating hormone synthesis and fertility are intact in mice lacking SMAD3 DNA binding activity and SMAD2 in gonadotrope cells.