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Endogenous catecholamines suppress thyrotropin secretion during the early follicular phase of the menstrual cycle.
J Clin Endocrinol Metab 1995; 80(8):2530-3JC

Abstract

The physiological role of hypothalamic catecholamines in the regulation of TSH secretion in humans has not been studied extensively. We administered the catecholamine synthesis inhibitor alpha-methyl-p-tyrosine (AMPT) to five women in the early follicular phase (one of menstrual cycle days 2-5) of the menstrual cycle and compared TSH secretion patterns to those in five women at the same time in the cycle who did not receive AMPT. From 0800-1600 h, volunteers had an i.v. line placed, through which blood was withdrawn every 15 min for TSH and PRL determinations. AMPT (500 mg) was administered to the study group at 0800 h and again at 1000 h. Baseline TSH concentrations at 0800 h were not significantly different between the control and treatment groups. In keeping with its characteristic circadian secretion pattern, TSH in the control group was 1.72 +/- 0.23 mIU/L at 0800 h, declined to 1.02 +/- 0.11 mIU/L by 1600 h, and was significantly less than the 0800 h value at all time points beyond 1115 h. The decline in TSH was observed in all five controls. By contrast, TSH in the AMPT group rose from an 0800 h value of 1.99 +/- 0.09 mIU/L to a peak of 3.30 +/- 0.86 IU/L by 1245 h, and was significantly higher than that at 0800 h in the treated group from 1130-1315 h. The increase in TSH was observed in all five women who received AMPT. There were significant differences between the mean TSH concentrations in the AMPT-treated (2.51 +/- 0.09 mIU/L) vs. the control group (1.28 +/- 0.09 mIU/L; P < 0.0001) for the entire study. The effectiveness of AMPT was demonstrated by an elevation of mean PRL concentrations from a baseline of 16.67 +/- 2.55 micrograms/L to a peak of 138.7 +/- 21.6 micrograms/L. We conclude that endogenous catecholamines tonically inhibit TSH secretion in the early follicular phase. These data suggest modulation of TRH by tuberoinfundibular dopamine at the hypothalamic and/or pituitary level.

Authors+Show Affiliations

Department of Obstetrics, Gynecology, University of California, San Francisco 94143, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

7629255

Citation

Plosker, S M., et al. "Endogenous Catecholamines Suppress Thyrotropin Secretion During the Early Follicular Phase of the Menstrual Cycle." The Journal of Clinical Endocrinology and Metabolism, vol. 80, no. 8, 1995, pp. 2530-3.
Plosker SM, Rabinovici J, Montalvo M, et al. Endogenous catecholamines suppress thyrotropin secretion during the early follicular phase of the menstrual cycle. J Clin Endocrinol Metab. 1995;80(8):2530-3.
Plosker, S. M., Rabinovici, J., Montalvo, M., & Jaffe, R. B. (1995). Endogenous catecholamines suppress thyrotropin secretion during the early follicular phase of the menstrual cycle. The Journal of Clinical Endocrinology and Metabolism, 80(8), pp. 2530-3.
Plosker SM, et al. Endogenous Catecholamines Suppress Thyrotropin Secretion During the Early Follicular Phase of the Menstrual Cycle. J Clin Endocrinol Metab. 1995;80(8):2530-3. PubMed PMID: 7629255.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Endogenous catecholamines suppress thyrotropin secretion during the early follicular phase of the menstrual cycle. AU - Plosker,S M, AU - Rabinovici,J, AU - Montalvo,M, AU - Jaffe,R B, PY - 1995/8/1/pubmed PY - 1995/8/1/medline PY - 1995/8/1/entrez SP - 2530 EP - 3 JF - The Journal of clinical endocrinology and metabolism JO - J. Clin. Endocrinol. Metab. VL - 80 IS - 8 N2 - The physiological role of hypothalamic catecholamines in the regulation of TSH secretion in humans has not been studied extensively. We administered the catecholamine synthesis inhibitor alpha-methyl-p-tyrosine (AMPT) to five women in the early follicular phase (one of menstrual cycle days 2-5) of the menstrual cycle and compared TSH secretion patterns to those in five women at the same time in the cycle who did not receive AMPT. From 0800-1600 h, volunteers had an i.v. line placed, through which blood was withdrawn every 15 min for TSH and PRL determinations. AMPT (500 mg) was administered to the study group at 0800 h and again at 1000 h. Baseline TSH concentrations at 0800 h were not significantly different between the control and treatment groups. In keeping with its characteristic circadian secretion pattern, TSH in the control group was 1.72 +/- 0.23 mIU/L at 0800 h, declined to 1.02 +/- 0.11 mIU/L by 1600 h, and was significantly less than the 0800 h value at all time points beyond 1115 h. The decline in TSH was observed in all five controls. By contrast, TSH in the AMPT group rose from an 0800 h value of 1.99 +/- 0.09 mIU/L to a peak of 3.30 +/- 0.86 IU/L by 1245 h, and was significantly higher than that at 0800 h in the treated group from 1130-1315 h. The increase in TSH was observed in all five women who received AMPT. There were significant differences between the mean TSH concentrations in the AMPT-treated (2.51 +/- 0.09 mIU/L) vs. the control group (1.28 +/- 0.09 mIU/L; P < 0.0001) for the entire study. The effectiveness of AMPT was demonstrated by an elevation of mean PRL concentrations from a baseline of 16.67 +/- 2.55 micrograms/L to a peak of 138.7 +/- 21.6 micrograms/L. We conclude that endogenous catecholamines tonically inhibit TSH secretion in the early follicular phase. These data suggest modulation of TRH by tuberoinfundibular dopamine at the hypothalamic and/or pituitary level. SN - 0021-972X UR - https://www.unboundmedicine.com/medline/citation/7629255/Endogenous_catecholamines_suppress_thyrotropin_secretion_during_the_early_follicular_phase_of_the_menstrual_cycle_ L2 - https://academic.oup.com/jcem/article-lookup/doi/10.1210/jcem.80.8.7629255 DB - PRIME DP - Unbound Medicine ER -