Growth hormone responses to GABAB receptor stimulation throughout the menstrual cycle of healthy females

✍ Scribed by Veronica O'Keane; Timothy G. Dinan

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 509 KB
• Volume: 9
• Category: Article
• ISSN: 0885-6222
• DOI: 10.1002/hup.470090207

✦ Synopsis

Growth hormone (GH) responses to the GABA, agonist baclofen (10 mg) were assessed in six normally cycling, healthy women at three different sex steroid phases of the menstrual cycle: early follicular, pre-ovulatory and luteal. The design was placebo-controlled, balanced and single-blind with a total of six tests being carried out on each subject in two consecutive menstrual cycles. GH responses to baclofen increased incrementally from early-, through mid-to late-cycle: 10.95 f 0.95 pgA, 24.53 f 4-73 pgil, 31 -36 f 3-37 pgA respectively (p < 0.04). Responses between early-and mid-cycle and early-and late-cycle were significantly different 0, < 0.05). There was a direct relationship between baclofedGH responses and both plasma oestradiol (E2) concentrations 0, = 0.05) and plasma progesterone concentrations (p = 0.02). Responses to placebo did not vary. E2 has been demonstrated to exert a priming influence on G H responses to many pharmacological and physiological stimuli. An E,-induced priming effect on GH secretion may underlie these results. Progesterone may augment this effect. Other possible influences are a sex steroid effect on somatostatin or GABA neurotransmission.