This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Loche, S. Articles by Ghigo, E. Search for Related Content PubMed PubMed Citation Articles by Loche, S. Articles by Ghigo, E.

The Growth Hormone Response to Hexarelin in Children: Reproducibility and Effect of Sex Steroids¹

Servizio di Endocrinologia Pediatrica, Ospedale Regionale per le Microcitemie (S.L., A.F.), Cagliari; Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Università Federico II (A.C., G.L.), Naples; Divisione di Endocrinologia, Ospedale Bambino Gesù IRCCS (M.C.), Palidoro, Rome; Divisione di Endocrinologia, Dipartimento di Fisiopatologia Clinica, Università di Torino (J.B., G.A., E.G.), Torino; and Clinica Pediatrica, Università di L’Aquila (G.F.), L’Aquila, Italy; and Europeptides (R.D.), Argenteuil, France

Address all correspondence and requests for reprints to: Sandro Loche, M.D., Servizio di Endocrinologia Pediatrica, Ospedale Regionale per le Microcitemie, via Jenner, 09121 Cagliari, Italy.

We studied the variability of the GH response to the synthetic hexapeptide hexarelin (Hex) and the effect of sex steroids on the GH-releasing effect of Hex in a group of prepubertal short normal children. Twenty-five children were tested on two occasions 3–7 days apart with 2 µg/kg, iv, Hex. The GH response to Hex was reevaluated after testosterone (T) administration in 10 boys, after ethinyl estradiol (EE) administration in 15 children (5 boys and 10 girls), and after oxandrolone (Ox) administration in 8 boys. In the 25 children tested twice, the mean GH peak and mean area under the curve after the first and second tests were similar. The mean (±SD) coefficients of variation of the GH peak and area under the curve responses to Hex was 22.7 ± 21.0% and 24.0 ± 20.7%, respectively. Priming with T and EE resulted in an increased GH response to Hex [41.8 ± 21.0 before vs. 71.1 ± 28.3 after T (P < 0.001); 43.0 ± 14.5 before vs. 60.0 ± 20.0 after EE (P < 0.005)], whereas Ox administration had no effect on the Hex-induced GH release. These data confirm that Hex is a potent stimulus for GH secretion in children with a limited intraindividual variability. In addition, we have shown that both T and EE, but not Ox, significantly augment the GH-releasing effect of Hex. Our data suggest that the sex steroid-induced increase in the GH response to Hex is mediated by estrogens.

This article has been cited by other articles:

				R. Muniyappa, J. D. Sorkin, J. D. Veldhuis, S. M. Harman, T. Munzer, S. Bhasin, and M. R. Blackman Long-term testosterone supplementation augments overnight growth hormone secretion in healthy older men Am J Physiol Endocrinol Metab, September 1, 2007; 293(3): E769 - E775. [Abstract] [Full Text] [PDF]

				L. S. Farhy, C. Y. Bowers, and J. D. Veldhuis Model-projected mechanistic bases for sex differences in growth hormone regulation in humans Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2007; 292(4): R1577 - R1593. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, D. M. Keenan, A. Iranmanesh, K. Mielke, J. M. Miles, and C. Y. Bowers Estradiol Potentiates Ghrelin-Stimulated Pulsatile Growth Hormone Secretion in Postmenopausal Women J. Clin. Endocrinol. Metab., September 1, 2006; 91(9): 3559 - 3565. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, J. N. Roemmich, E. J. Richmond, and C. Y. Bowers Somatotropic and Gonadotropic Axes Linkages in Infancy, Childhood, and the Puberty-Adult Transition Endocr. Rev., April 1, 2006; 27(2): 101 - 140. [Abstract] [Full Text] [PDF]

				J. D Veldhuis, D. M Keenan, K. Mielke, J. M Miles, and C. Y Bowers Testosterone supplementation in healthy older men drives GH and IGF-I secretion without potentiating peptidyl secretagogue efficacy Eur. J. Endocrinol., October 1, 2005; 153(4): 577 - 586. [Abstract] [Full Text] [PDF]

				L. S. Farhy and J. D. Veldhuis Deterministic construct of amplifying actions of ghrelin on pulsatile growth hormone secretion Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2005; 288(6): R1649 - R1663. [Abstract] [Full Text] [PDF]

				C. Soares-Welch, L. Farhy, K. L. Mielke, F. H. Mahmud, J. M. Miles, C. Y. Bowers, and J. D. Veldhuis Complementary Secretagogue Pairs Unmask Prominent Gender-Related Contrasts in Mechanisms of Growth Hormone Pulse Renewal in Young Adults J. Clin. Endocrinol. Metab., April 1, 2005; 90(4): 2225 - 2232. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, J. T. Patrie, K. T. Brill, J. Y. Weltman, E. E. Mueller, C. Y. Bowers, and A. Weltman Contributions of Gender and Systemic Estradiol and Testosterone Concentrations to Maximal Secretagogue Drive of Burst-Like Growth Hormone Secretion in Healthy Middle-Aged and Older Adults J. Clin. Endocrinol. Metab., December 1, 2004; 89(12): 6291 - 6296. [Abstract] [Full Text] [PDF]

				A. J. van der Lely, M. Tschop, M. L. Heiman, and E. Ghigo Biological, Physiological, Pathophysiological, and Pharmacological Aspects of Ghrelin Endocr. Rev., June 1, 2004; 25(3): 426 - 457. [Abstract] [Full Text] [PDF]

				C. Y. Bowers, R. Granda, S. Mohan, J. Kuipers, D. Baylink, and J. D. Veldhuis Sustained Elevation of Pulsatile Growth Hormone (GH) Secretion and Insulin-Like Growth Factor I (IGF-I), IGF-Binding Protein-3 (IGFBP-3), and IGFBP-5 Concentrations during 30-Day Continuous Subcutaneous Infusion of GH-Releasing Peptide-2 in Older Men and Women J. Clin. Endocrinol. Metab., May 1, 2004; 89(5): 2290 - 2300. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, W. S. Evans, A. Iranmanesh, A. L. Weltman, and C. Y. Bowers Short-Term Testosterone Supplementation Relieves Growth Hormone Autonegative Feedback in Men J. Clin. Endocrinol. Metab., March 1, 2004; 89(3): 1285 - 1290. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, S. M. Anderson, J. T. Patrie, and C. Y. Bowers Estradiol Supplementation in Postmenopausal Women Doubles Rebound-Like Release of Growth Hormone (GH) Triggered by Sequential Infusion and Withdrawal of Somatostatin: Evidence that Estrogen Facilitates Endogenous GH-Releasing Hormone Drive J. Clin. Endocrinol. Metab., January 1, 2004; 89(1): 121 - 127. [Abstract] [Full Text] [PDF]

				E. Richmond, A. D. Rogol, D. Basdemir, O. L. Veldhuis, W. Clarke, C. Y. Bowers, and J. D. Veldhuis Accelerated Escape from GH Autonegative Feedback in Midpuberty in Males: Evidence for Time-Delimited GH-Induced Somatostatinergic Outflow in Adolescent Boys J. Clin. Endocrinol. Metab., August 1, 2002; 87(8): 3837 - 3844. [Abstract] [Full Text] [PDF]

				S. M. Anderson, L. Wideman, J. T. Patrie, A. Weltman, C. Y. Bowers, and J. D. Veldhuis E2 Supplementation Selectively Relieves GH's Autonegative Feedback on GH-Releasing Peptide-2-Stimulated GH Secretion J. Clin. Endocrinol. Metab., December 1, 2001; 86(12): 5904 - 5911. [Abstract] [Full Text] [PDF]

				M. J. Bray, T. M. Vick, N. Shah, S. M. Anderson, L. W. Rice, A. Iranmanesh, W. S. Evans, and J. D. Veldhuis Short-Term Estradiol Replacement in Postmenopausal Women Selectively Mutes Somatostatin's Dose-Dependent Inhibition of Fasting Growth Hormone Secretion J. Clin. Endocrinol. Metab., July 1, 2001; 86(7): 3143 - 3149. [Abstract] [Full Text] [PDF]

				S. M. Anderson, N. Shah, W. S. Evans, J. T. Patrie, C. Y. Bowers, and J. D. Veldhuis Short-Term Estradiol Supplementation Augments Growth Hormone (GH) Secretory Responsiveness to Dose-Varying GH-Releasing Peptide Infusions in Healthy Postmenopausal Women J. Clin. Endocrinol. Metab., February 1, 2001; 86(2): 551 - 560. [Abstract] [Full Text]

				N. Shah, W. S. Evans, C. Y. Bowers, and J. D. Veldhuis Oral Estradiol Administration Modulates Continuous Intravenous Growth Hormone (GH)-Releasing Peptide-2-Driven GH Secretion in Postmenopausal Women J. Clin. Endocrinol. Metab., August 1, 2000; 85(8): 2649 - 2659. [Abstract] [Full Text]

				E. E. Muller, V. Locatelli, and D. Cocchi Neuroendocrine Control of Growth Hormone Secretion Physiol Rev, April 1, 1999; 79(2): 511 - 607. [Abstract] [Full Text] [PDF]

				D. F. Carmignac, P. A. Bennett, and I. C. A. F. Robinson Effects of Growth Hormone Secretagogues on Prolactin Release in Anesthetized Dwarf (dw/dw) Rats Endocrinology, August 1, 1998; 139(8): 3590 - 3596. [Abstract] [Full Text] [PDF]