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Catecholamines and pituitary function. I. Effects of catecholamine synthesis inhibition and subsequent catecholamine infusion on gonadotropin and prolactin serum levels in normal cycling women and in women with hyperprolactinemic amenorrhea.
Horm Res 1984; 19(3):158-70HR

Abstract

To investigate the role of catecholamines in the control of gonadotropin and prolactin release, we examined the effects of a catecholamine synthesis inhibitor (alpha-methyl-p-tyrosine, AMPT) administration and those of dopamine (DA) or epinephrine (EPI) infusion after endogenous catecholamine synthesis inhibition, on FSH, LH and PRL serum levels, in regularly cycling women and in patients with hyperprolactinemic amenorrhea. AMPT administration was followed by a prompt increase in serum PRL in regularly cycling women, but not in women with hyperprolactinemia either due to a PRL-secreting pituitary microadenoma or 'idiopathic'. Gonadotropin serum levels did not show any significant variation after AMPT in both normal and hyperprolactinemic women. DA infusion after endogenous catecholamine synthesis inhibition by AMPT, induced an appreciable decline in PRL levels in both normal and hyperprolactinemic subjects. Although the net decrements were higher in the hyperprolactinemic group, the PRL fall was similar in the two groups when expressed as a percentage of preinfusion PRL concentrations. LH serum levels similarly fell during DA infusion in normal women and in hyperprolactinemic patients, while FSH concentrations did not show any significant change. EPI infusion after analogous AMPT pretreatment was followed by an evident decrease in serum PRL in both normal and hyperprolactinemic subjects. No significant changes in FSH and LH serum concentrations were observed during EPI administration. These data, while confirming the existence of a functional derangement in the neural inhibitory control of PRL secretion in hyperprolactinemia either due to a PRL-secreting pituitary microadenoma or so-called 'idiopathic', do not agree with the hypothesis that tubero-infundibular DA hyperactivity inhibits gonadotropin secretion in hyperprolactinemic patients. The inhibitory action of exogenously administered DA might represent rather a pharmacological effect than express a physiological inhibitory role of hypothalamic DA pathway on gonadotropin secretion in humans.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

6425187

Citation

Nicoletti, I, et al. "Catecholamines and Pituitary Function. I. Effects of Catecholamine Synthesis Inhibition and Subsequent Catecholamine Infusion On Gonadotropin and Prolactin Serum Levels in Normal Cycling Women and in Women With Hyperprolactinemic Amenorrhea." Hormone Research, vol. 19, no. 3, 1984, pp. 158-70.
Nicoletti I, Filipponi P, Sfrappini M, et al. Catecholamines and pituitary function. I. Effects of catecholamine synthesis inhibition and subsequent catecholamine infusion on gonadotropin and prolactin serum levels in normal cycling women and in women with hyperprolactinemic amenorrhea. Horm Res. 1984;19(3):158-70.
Nicoletti, I., Filipponi, P., Sfrappini, M., Fedeli, L., Petrelli, S., Gregorini, G., ... Brunetti, P. (1984). Catecholamines and pituitary function. I. Effects of catecholamine synthesis inhibition and subsequent catecholamine infusion on gonadotropin and prolactin serum levels in normal cycling women and in women with hyperprolactinemic amenorrhea. Hormone Research, 19(3), pp. 158-70.
Nicoletti I, et al. Catecholamines and Pituitary Function. I. Effects of Catecholamine Synthesis Inhibition and Subsequent Catecholamine Infusion On Gonadotropin and Prolactin Serum Levels in Normal Cycling Women and in Women With Hyperprolactinemic Amenorrhea. Horm Res. 1984;19(3):158-70. PubMed PMID: 6425187.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Catecholamines and pituitary function. I. Effects of catecholamine synthesis inhibition and subsequent catecholamine infusion on gonadotropin and prolactin serum levels in normal cycling women and in women with hyperprolactinemic amenorrhea. AU - Nicoletti,I, AU - Filipponi,P, AU - Sfrappini,M, AU - Fedeli,L, AU - Petrelli,S, AU - Gregorini,G, AU - Santeusanio,F, AU - Brunetti,P, PY - 1984/1/1/pubmed PY - 1984/1/1/medline PY - 1984/1/1/entrez SP - 158 EP - 70 JF - Hormone research JO - Horm. Res. VL - 19 IS - 3 N2 - To investigate the role of catecholamines in the control of gonadotropin and prolactin release, we examined the effects of a catecholamine synthesis inhibitor (alpha-methyl-p-tyrosine, AMPT) administration and those of dopamine (DA) or epinephrine (EPI) infusion after endogenous catecholamine synthesis inhibition, on FSH, LH and PRL serum levels, in regularly cycling women and in patients with hyperprolactinemic amenorrhea. AMPT administration was followed by a prompt increase in serum PRL in regularly cycling women, but not in women with hyperprolactinemia either due to a PRL-secreting pituitary microadenoma or 'idiopathic'. Gonadotropin serum levels did not show any significant variation after AMPT in both normal and hyperprolactinemic women. DA infusion after endogenous catecholamine synthesis inhibition by AMPT, induced an appreciable decline in PRL levels in both normal and hyperprolactinemic subjects. Although the net decrements were higher in the hyperprolactinemic group, the PRL fall was similar in the two groups when expressed as a percentage of preinfusion PRL concentrations. LH serum levels similarly fell during DA infusion in normal women and in hyperprolactinemic patients, while FSH concentrations did not show any significant change. EPI infusion after analogous AMPT pretreatment was followed by an evident decrease in serum PRL in both normal and hyperprolactinemic subjects. No significant changes in FSH and LH serum concentrations were observed during EPI administration. These data, while confirming the existence of a functional derangement in the neural inhibitory control of PRL secretion in hyperprolactinemia either due to a PRL-secreting pituitary microadenoma or so-called 'idiopathic', do not agree with the hypothesis that tubero-infundibular DA hyperactivity inhibits gonadotropin secretion in hyperprolactinemic patients. The inhibitory action of exogenously administered DA might represent rather a pharmacological effect than express a physiological inhibitory role of hypothalamic DA pathway on gonadotropin secretion in humans. SN - 0301-0163 UR - https://www.unboundmedicine.com/medline/citation/6425187/Catecholamines_and_pituitary_function__I__Effects_of_catecholamine_synthesis_inhibition_and_subsequent_catecholamine_infusion_on_gonadotropin_and_prolactin_serum_levels_in_normal_cycling_women_and_in_women_with_hyperprolactinemic_amenorrhea_ L2 - https://www.karger.com?DOI=10.1159/000179883 DB - PRIME DP - Unbound Medicine ER -