Independent and combined effects of testosterone and growth hormone on extracellular water in hypopituitary men.
Johannsson G - J Clin Endocrinol Metab - 01-JUL-2005; 90(7): 3989-94
From NIH/NLM MEDLINE
NLM Citation ID:
15827107 (PubMed)
Full Source Title:
Journal of Clinical Endocrinology and Metabolism
Publication Type:
Clinical Trial; Journal Article; Randomized Controlled Trial
Language:
English
Author Affiliation:
Pituitary Research Unit, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney, New South Wales 2010, Australia.
Authors:
Johannsson G; Gibney J; Wolthers T; Leung KC; Ho KK
Abstract:
CONTEXT: Symptoms of fluid retention in GH-deficient patients during GH replacement are greater in men than in women, suggesting that testosterone may augment or estradiol may attenuate the antinatriuretic actions of GH. The mechanisms underlying the sodium-retaining effects of GH are poorly understood. AIM: The aim of this study was to investigate the effects of GH and testosterone, alone and in combination, on extracellular water (ECW) and the hormonal mechanisms involved. DESIGN: Two separate, open-label, randomized, two-period, crossover studies were performed; the first compared the effects of GH alone with those of GH and testosterone, and the second compared the effects of testosterone alone with those of GH and testosterone. PARTICIPANTS: Twelve hypopituitary men with GH deficiency and hypogonadism were studied. INTERVENTION: During the weeks of intervention, GH (0.5 mg/d) and testosterone enanthate (250 mg) were administered by im injection. OUTCOME MEASURES: The outcome measures were ECW, IGF-I, plasma renin activity (PRA), aldosterone (Aldo), and atrial natriuretic peptide (ANP). RESULTS: GH treatment significantly increased (P < 0.05) both IGF-I and ECW, and these changes were enhanced by cotreatment with testosterone (P = 0.07 for both). PRA, Aldo, and ANP levels did not change. Testosterone treatment alone did not change the IGF-I concentration, whereas cotreatment with GH induced a marked increase. Testosterone alone increased (P < 0.05) ECW, and the effect was augmented (P < 0.01) by cotreatment with GH. Although PRA and ANP did not change, plasma Aldo decreased after single and combined treatments. CONCLUSION: GH and testosterone exerted independent and additive effects on ECW. The mechanisms of fluid retention for both hormones are likely to be exerted on the renal tubules. This is the first direct evidence that testosterone increases ECW.
Major Subjects:
- Body Water / * metabolism
- Extracellular Fluid / * metabolism
- Hormone Replacement Therapy
- Human Growth Hormone / * deficiency / * therapeutic use
- Hypopituitarism / * drug therapy / metabolism
- Testosterone / * therapeutic use
Additional Subjects:
- Adult
- Aged
- Aldosterone / blood
- Atrial Natriuretic Factor / blood
- Cross-Over Studies
- Drug Synergism
- Humans
- Insulin-Like Growth Factor I / analysis
- Male
- Middle Aged
- Research Support, Non-U.S. Gov't
Chemical Compound Name:
12629-01-5(Human Growth Hormone); 52-39-1(Aldosterone); 58-22-0(Testosterone); 67763-96-6(Insulin-Like Growth Factor I); 85637-73-6(Atrial Natriuretic Factor)