Role of intron 5 C/T polymorphism of the kalcium sensing receptor gene in the regulation of the serum FSH and LH in post-menopausal women.
Abstract
Objective: High extracellular calcium concentration (Ca-o(2+)) acts to inhibit calcium sensing receptor (CaR) signalling on cellular surfaces in parathyroid glands. This receptor is, however, also expressed on the membranes of some non-calciotropic endocrine cells, including pituitary-derived cells.
The aim of our study was to analyse relationships between the CaR gene and the circulating FSH and LH in normal postmenopausal women. Methods: A total of 95 untreated euparathyroid post-menopausal women were investigated in the study.
The serum FSH and LH levels were evaluated in relationship to allele combinations of the CaR gene (C/T polymorphism in the intron 5 and A986S polymorphism in exon 7), using an analysis of co-variance (ANCOVA) model. Results: Distribution of TT, TC and CC allele combinations (intron 5 C/T polymorphism) was 51, 43 and 6 %, respectively.
Higher serum FSH and LH levels were found in carriers of C allele than in women without this allele (p<0.002 and p<0.03, respectively). No correlations were found between A986S polymorphism and serum FSH and LH levels.
Conclusions: Serum FSH and LH levels are associated with intron 5 C/T (but not A986S) polymorphism of the CaR gene in untreated post-menopausal women. The physiological role of the CaR gene in the regulation of the gonadotropic function needs to be further investigated.