Synergy of L-arginine and GHRP-2 stimulation of growth hormone in men and women: Modulation by exercise

Laurie Wideman, Judy Y. Weltman, James T. Patrie, Cyril Y. Bowers, Niki Shah, Shannon Story, Johannes D Veldhuis, Arthur Weltman

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

We investigated the ability of exercise, a multipathway, potent, physiological stimulus for GH release, to alter the synergistic interaction of L-arginine (A) and GH-related peptide (GHRP)-2 (G) observed at rest and the ability of gender to further modulate this putative interaction. Subjects (9 men and 9 early follicular phase women) completed 30 min of constant load aerobic exercise in combination with intravenous infusions of saline (S), A (30 g over 30 min), G (1 μg/kg bolus), or both (AG) in separate study sessions in randomly assigned order. Measures of GH release were logarithmically transformed for statistical analysis. Similar to rest, exercise maintained the rank order (AG > G > A > S) of effective stimulation of GH release for the key response measures in men or women, a gender disparity in the time to reach the maximal serum GH concentration, the calculated endogenous GH half-life, and the observed effect of preinfusion (basal) serum GH concentrations on determining secretagogue responsiveness. Exercise potentiated the individual stimulatory actions of A and G, while blunting the relative magnitude of the synergistic (supra-additive) interaction observed at rest. We infer from the present data that 1) exercise is likely to induce release of both GHRH and somatostatin, 2) L-arginine may facilitate the effect of exercise by limiting somatostatin release, 3) GHRP-2 could further enhance the stimulatory impact of exercise by opposing central actions of somatostatin and/or heightening endogenous GHRH release, and 4) gender strongly controls the relative but not absolute magnitude of A/G synergy both at rest and after exercise.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume279
Issue number4 48-4
StatePublished - 2000
Externally publishedYes

Fingerprint

Growth Hormone
Arginine
Exercise
Peptides
Somatostatin
Follicular Phase
Serum
Intravenous Infusions
Half-Life

Keywords

  • Endocrine
  • Female
  • Male
  • Pituitary
  • Regulation
  • Somatotropin

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Synergy of L-arginine and GHRP-2 stimulation of growth hormone in men and women : Modulation by exercise. / Wideman, Laurie; Weltman, Judy Y.; Patrie, James T.; Bowers, Cyril Y.; Shah, Niki; Story, Shannon; Veldhuis, Johannes D; Weltman, Arthur.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 279, No. 4 48-4, 2000.

Research output: Contribution to journalArticle

Wideman, L, Weltman, JY, Patrie, JT, Bowers, CY, Shah, N, Story, S, Veldhuis, JD & Weltman, A 2000, 'Synergy of L-arginine and GHRP-2 stimulation of growth hormone in men and women: Modulation by exercise', American Journal of Physiology - Regulatory Integrative and Comparative Physiology, vol. 279, no. 4 48-4.
Wideman, Laurie ; Weltman, Judy Y. ; Patrie, James T. ; Bowers, Cyril Y. ; Shah, Niki ; Story, Shannon ; Veldhuis, Johannes D ; Weltman, Arthur. / Synergy of L-arginine and GHRP-2 stimulation of growth hormone in men and women : Modulation by exercise. In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology. 2000 ; Vol. 279, No. 4 48-4.
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