Biogerontology

, Volume 6, Issue 5, pp 303–312

Effect of Recombinant Human Growth Hormone Administration on Body Composition and Vascular Function and Structure in Old Male Wistar Rats

  • Carmen Castillo
  • Mar Cruzado
  • Carmen Ariznavarreta
  • Pablo Gil-Loyzaga
  • Vicente Lahera
  • Victoria Cachofeiro
  • Jesús A. F. Tresguerres
Research Article

DOI: 10.1007/s10522-005-4805-3

Cite this article as:
Castillo, C., Cruzado, M., Ariznavarreta, C. et al. Biogerontology (2005) 6: 303. doi:10.1007/s10522-005-4805-3

Abstract

The process of ageing affects negatively both cardiovascular system and body composition. On the other hand, the hormones of the somatotrophic axis, growth hormone (GH) and insulin-like growth factor-I (IGF-I), whose production is reduced by age, are involved in the regulation of the cardiovascular system. The aim of this study was to investigate the effect of GH on body composition, vascular function and structure in old male rats. Old (20 months) and adult (4 months) male Wistar rats were used. One group of old animals was treated with GH for 4 weeks. Periepididimary fat weight, Specific Gravity Index (SGI), dose responses to Acetylcholine (ACh), Isoproterenol (Iso), Phenylephrine (Phe) and ACh in the presence of NG-nitro-l-arginine metylester (l-NAME; ACh+l-NAME), as well as vascular morphology in aortic rings, were studied. Old rats showed increased fat weight and decreased SGI as compared to adult animals. GH increased SGI and tended to reduce fat weight. Old rats showed an impairment in the vasodilator response to ACh and Iso; GH significantly improved the vasodilatation induced by Iso, whereas the response to ACh was not significantly enhanced by GH treatment. There were no significant differences between adult and old rats in the contractile response to Phe, and GH did not show any effect. Contraction induced by ACh+l-NAME was higher in old rats as compared to adults, and treatment with GH significantly reduced this response. Aortic media area was increased in old rats, and GH administration reduced this parameter. In conclusion, GH shows beneficial effects on body composition, as well as on vascular function and morphology in old male rats.

Keywords

agingbody compositionendothelial functiongrowth hormonevascular structure

Abbreviations

rhGH

recombinant human growth hormone

IGF-1

insulin-like growth factor 1

GHD

growth hormone deficiency

SGI

specific gravity index

KCl

potassium chloride

ACh

acetylcholine

Iso

isoproterenol

SNP

sodium nitroprusside

Phe

phenylephrine

l-NAME

NG-nitro-l-arginine methylester

NO

nitric oxide

PGI2

prostacyclin

EDHF

endothelial-derived hyperpolarizing factor

TXA2

tromboxane A2

Copyright information

© Springer 2005

Authors and Affiliations

  • Carmen Castillo
    • 1
  • Mar Cruzado
    • 1
  • Carmen Ariznavarreta
    • 1
  • Pablo Gil-Loyzaga
    • 1
    • 2
  • Vicente Lahera
    • 1
  • Victoria Cachofeiro
    • 1
  • Jesús A. F. Tresguerres
    • 1
  1. 1.Department of Physiology, School of MedicineComplutense UniversityMadridSpain
  2. 2.Department of Surgery II (Neurobiology of Hearing), School of MedicineComplutense UniversityMadridSpain