title: Effects of cetrorelix, a GnRH-receptor antagonist, on gonadal axis in women with functional hypothalamic amenorrhea.
abstract: BACKGROUND
  Gonadotropin Releasing Hormone (GnRH) antagonists (GnRHa) suppress gonadotropin and sex-steroid secretion. In normal women, acute GnRHa administration induces inhibitory effect on pituitary-gonadal axis, followed by Luteinizing Hormone (LH) rebound. Functional hypothalamic amenorrhea (HA) is characterised by impaired gonadotropin secretion and hypogonadism secondary to blunted GnRH pulsatility.
  
  
  METHODS
  We studied the effects of a GnRHa, cetrorelix (CTX 3.0 mg), in six women with HA (age 30.7 ± 3.2 years; BMI 21.5 ± 1.7 kg/m(2)) and six control subjects (CS, 28.2 ± 0.6 years; 22.6 ± 0.9 kg/m(2)) on LH, Follicle-Stimulating Hormone (FSH) and oestradiol levels over 4 h (08.00-12.00 am) before, +24 h and +96 h after CTX; LH, FSH, and oestradiol were also evaluated at +6, +8, +12, +48, +72 h after CTX.
  
  
  RESULTS
  CS: CTX reduced (p < 0.05) LH, FSH, and oestradiol (nadir at +12 h, +24 h, and +24 h); LH rebounded at +96 h, FSH and oestradiol recovered at +48 h and +72 h. The 4-h evaluation showed LH and FSH reduction (p < 0.05) at +24 h, with LH rebound at +96 h. HA: CTX reduced (p < 0.05) LH, FSH, and oestradiol, (nadir at +24 h, +48 h, and +48 h, recovery at +48 h, +72 h, and +96 h). The 4-h evaluation showed gonadotropin reduction (p < 0.05) 24 h after CTX, without any rebound effect.
  
  
  CONCLUSIONS
  One single CTX dose still modulates gonadotropin secretion in HA. Its 'paradoxical' stimulatory effect on gonadotropins needs to be verified after prolonged administration.
authors.affiliation: Division of Endocrinology, Diabetology and Metabolism, Department of Internal Medicine, University of Turin, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Berardelli
authors.forename: Laura
authors.initials: L
authors.lastname: Gianotti
authors.forename: Ioannis
authors.initials: I
authors.lastname: Karamouzis
authors.forename: Andreea
authors.initials: A
authors.lastname: Picu
authors.forename: Roberta
authors.initials: R
authors.lastname: Giordano
authors.forename: Valentina
authors.initials: V
authors.lastname: D'Angelo
authors.forename: Domenico
authors.initials: D
authors.lastname: Zinnà
authors.forename: Fabio
authors.initials: F
authors.lastname: Lanfranco
authors.forename: Ezio
authors.initials: E
authors.lastname: Ghigo
authors.forename: Emanuela
authors.initials: E
authors.lastname: Arvat
mesh_terms: D000328:Adult; D000568:Amenorrhea / Q000097:blood* / Q000188:drug therapy; D004958:Estradiol / Q000097:blood; D005260:Female; D043373:Follicle Stimulating Hormone, Human / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006727:Hormone Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007027:Hypothalamic Diseases / Q000097:blood* / Q000188:drug therapy; D007986:Luteinizing Hormone / Q000097:blood; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism; D011966:Receptors, LHRH / Q000037:antagonists & inhibitors*; D013997:Time Factors
chemical_list: D043373:Follicle Stimulating Hormone, Human; D006727:Hormone Antagonists; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; C062876:cetrorelix