title: Does estrogen replacement therapy influence parathyroid hormone responsiveness to exogenous hypercalcemia in postmenopausal women?
abstract: In postmenopausal women PTH suppression by exogenous calcium is reduced. To test whether this finding might be caused by estrogen deficiency 9 postmenopausal women were given transdermal estradiol (E2) treatment for 3 months at a dose of 100 micrograms/day. PTH reactivity to iv administration of CaCl2 was determined before and at the end of the E2-treatment period. Compliance to treatment was checked by determination of serum levels of E2 and FSH. The E2 level rose from 0.1 +/- 0.02 (mean +/- SE) to 0.46 +/- 0.10 mmol/l p < 0.01), whereas the corresponding FSH level declined from 77.5 +/- 7.4 to 33.9 +/- 5.7 U/l p < 0.01). This suggests good compliance. At the end of E2-treatment period calcium administration induced a higher PTH suppression as compared with control value (the PTH decremental area 2123 +/- 270 vs 1253 +/- 253 ng/l x min, p < 0.05), although a lower calcemic response was attained (the Ca incremental area 32.6 +/- 6.1 vs 47.4 +/- 4.5 mmol/ml x min, p < 0.05). These results imply that parathyroid glands are dependent on an adequate estrogen provision to respond normally to serum calcium changes.
authors.affiliation: Institute of Endocrinology, Prague, Czech Republic.
authors.forename: I
authors.initials: I
authors.lastname: Zofková
authors.forename: S
authors.initials: S
authors.lastname: Röjdmark
authors.forename: R L
authors.initials: RL
authors.lastname: Kancheva
mesh_terms: D002122:Calcium Chloride; D004958:Estradiol / Q000627:therapeutic use; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000139:chemically induced / Q000503:physiopathology*; D008593:Menopause / Q000097:blood*; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D010281:Parathyroid Hormone; D004958:Estradiol; D002122:Calcium Chloride