title: The influence of oestrogens on the sensitivity of PRL, TSH and LH to the inhibitory actions of dopamine in hyperprolactinaemic patients.
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: D000328:Adult; D004298:Dopamine / Q000627:therapeutic use*; D004997:Ethinyl Estradiol / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000097:blood / Q000188:drug therapy*; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D008875:Middle Aged; D010908:Pituitary Hormones, Anterior / Q000378:metabolism*; D011388:Prolactin / Q000097:blood / Q000378:metabolism; D013629:Tamoxifen / Q000627:therapeutic use; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism; D013997:Time Factors
chemical_list: D010908:Pituitary Hormones, Anterior; D013629:Tamoxifen; D004997:Ethinyl Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D013972:Thyrotropin; D004298:Dopamine