This Article Full Text Full Text (PDF) All Versions of this Article: 90/7/3989    most recent Author Manuscript (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 Johannsson, G. Articles by Ho, K. K. Y. Search for Related Content PubMed PubMed Citation Articles by Johannsson, G. Articles by Ho, K. K. Y. Related Collections Neuroendocrinology and Pituitary Male Endocrinology

Independent and Combined Effects of Testosterone and Growth Hormone on Extracellular Water in Hypopituitary Men

Pituitary Research Unit, Garvan Institute of Medical Research and Department of Endocrinology, St. Vincent’s Hospital, Sydney, New South Wales 2010, Australia

Address all correspondence and requests for reprints to: Dr. Ken K. Y. Ho, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, New South Wales 2010, Australia. E-mail: k.ho{at}garvan.org.au.

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.

This article has been cited by other articles:

				P. Kamenicky, S. Viengchareun, A. Blanchard, G. Meduri, P. Zizzari, M. Imbert-Teboul, A. Doucet, P. Chanson, and M. Lombes Epithelial Sodium Channel Is a Key Mediator of Growth Hormone-Induced Sodium Retention in Acromegaly Endocrinology, July 1, 2008; 149(7): 3294 - 3305. [Abstract] [Full Text] [PDF]

				J. Gibney, M.-L. Healy, and P. H. Sonksen The Growth Hormone/Insulin-Like Growth Factor-I Axis in Exercise and Sport Endocr. Rev., October 1, 2007; 28(6): 603 - 624. [Abstract] [Full Text] [PDF]

				M. G. Burt, G. Johannsson, A. M. Umpleby, D. J. Chisholm, and K. K. Y. Ho Impact of Acute and Chronic Low-Dose Glucocorticoids on Protein Metabolism J. Clin. Endocrinol. Metab., October 1, 2007; 92(10): 3923 - 3929. [Abstract] [Full Text] [PDF]

				J. K. Devin, L. S. Blevins Jr., D. K. Verity, Q. Chen, J. R. Bloodworth Jr., J. Covington, and D. E. Vaughan Markedly Impaired Fibrinolytic Balance Contributes to Cardiovascular Risk in Adults with Growth Hormone Deficiency J. Clin. Endocrinol. Metab., September 1, 2007; 92(9): 3633 - 3639. [Abstract] [Full Text] [PDF]

				K. Sjogren, K.-C. Leung, W. Kaplan, M. Gardiner-Garden, J. Gibney, and K. K. Y. Ho Growth hormone regulation of metabolic gene expression in muscle: a microarray study in hypopituitary men Am J Physiol Endocrinol Metab, July 1, 2007; 293(1): E364 - E371. [Abstract] [Full Text] [PDF]

				R. Muniyappa, K. A. Wong, H. L. Baldwin, J. D. Sorkin, M. L. Johnson, S. Bhasin, S. M. Harman, and M. R. Blackman Dehydroepiandrosterone Secretion in Healthy Older Men and Women: Effects of Testosterone and Growth Hormone Administration in Older Men J. Clin. Endocrinol. Metab., November 1, 2006; 91(11): 4445 - 4452. [Abstract] [Full Text] [PDF]