title: Three-peptide control of pulsatile and entropic feedback-sensitive modes of growth hormone secretion: modulation by estrogen and aromatizable androgen.
abstract: The present review highlights a simplified perspective of growth hormone (GH) secretory control, which incorporates the individual and joint effects of final-common signals that converge on somatotrope cells. Critical peptidyl effectors are GH-releasing hormone (GHRH), GH-releasing peptide (GHRP, ghrelin), and somatostatin. The latter three-peptide ensemble mediates stimulation, inhibition, and feedback suppression of GH secretion via homologous and heterologous interactions. Pubertal sex steroids putatively act via post-aromatized estrogen (e.g., testosterone converted to estradiol by aromatase) to augment sensitivity to GHRH, potentiate GHRP action, and mute somatostatin restraint. The dynamic interactions in this three-peptide network, rather than the activity of any single effector, subserve core adaptations in GH secretion across development.
authors.affiliation: Mayo Clinic and Graduate School of Medicine, Division of Endocrinology and Metabolism, Department of Internal Medicine, Rochester, MN 55905, USA. veldhuis.Johannes@mayo.edu
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Veldhuis
authors.forename: Cyril Y
authors.initials: CY
authors.lastname: Bowers
mesh_terms: D000728:Androgens / Q000378:metabolism / Q000493:pharmacokinetics*; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D019277:Entropy; D004967:Estrogens / Q000378:metabolism / Q000493:pharmacokinetics*; D025461:Feedback, Physiological; D054439:Ghrelin; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism / Q000493:pharmacokinetics; D019382:Human Growth Hormone / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D036361:Peptide Hormones / Q000378:metabolism / Q000493:pharmacokinetics; D011673:Pulsatile Flow / Q000502:physiology*; D013004:Somatostatin / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics
chemical_list: D000728:Androgens; D004967:Estrogens; D054439:Ghrelin; D036361:Peptide Hormones; D019382:Human Growth Hormone; D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone; D001141:Aromatase