The influence of oestrogens on the sensitivity of PRL, TSH and LH to the inhibitory actions of dopamine in hyperprolactinaemic patients

Clin Endocrinol (Oxf). 1985 Aug;23(2):139-46. doi: 10.1111/j.1365-2265.1985.tb00208.x.

Abstract

The effects of oestrogen priming on the response of serum PRL, LH and TSH to dopamine (DA) infusion have been studied in hyperprolactinaemia. Seven hyperprolactinaemic females (aged 22-57 years; basal PRL 911-5130 mU/l, normal less than 420 mU/l), had submaximal DA infusions (0.06 micrograms/kg/min) over 3 h. The DA was repeated at the same dose after pretreatment with ethinyl oestradiol (E2) 100 micrograms daily by mouth for 3 d, and after a further 2 week interval, following pretreatment with tamoxifen (TAM) 20 mg twice a day by mouth for 3 d. Ethinyl oestradiol pretreatment stimulated a rise in basal PRL levels in all subjects (mean +/- SE, mU/l; 2903 +/- 761 vs 2293 +/- 684, P less than 0.05) while TAM produced a higher but more variable increase in basal PRL levels (mean +/- SE, mU/l; 3402 +/- 757, P = n.s.). The individual increments in basal PRL levels after both E2 and TAM pretreatment showed a significant positive correlation with the greater decrement in PRL levels during E2 and TAM primed DA infusions (E2, r = 0.93, P less than 0.01, TAM, r = 0.83, P less than 0.05). E2 pretreatment produced a rise in basal LH levels in 5/7 patients, and there was a significant positive correlation between the rise in basal LH levels after E2 and the decremental change in LH levels in E2 primed DA infusions (r = 0.94, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

MeSH terms

  • Adult
  • Dopamine / therapeutic use*
  • Ethinyl Estradiol / therapeutic use*
  • Female
  • Humans
  • Hyperprolactinemia / blood
  • Hyperprolactinemia / drug therapy*
  • Luteinizing Hormone / blood
  • Luteinizing Hormone / metabolism
  • Middle Aged
  • Pituitary Hormones, Anterior / metabolism*
  • Prolactin / blood
  • Prolactin / metabolism
  • Tamoxifen / therapeutic use
  • Thyrotropin / blood
  • Thyrotropin / metabolism
  • Time Factors

Substances

  • Pituitary Hormones, Anterior
  • Tamoxifen
  • Ethinyl Estradiol
  • Prolactin
  • Luteinizing Hormone
  • Thyrotropin
  • Dopamine