| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Pituitary Research Unit, Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, New South Wales 2010; 2 Australian Sports Drug Testing Laboratory, Australian Government Analytical Laboratories, Sydney, New South Wales 2073, Australia; and 3 Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908
The 20-kDa growth hormone (GH) is generated from alternative splicing of the primary transcript of full-length 22-kDa GH. We have studied the regulation of 20-kDa GH over a range of pathophysiological conditions and in response to pharmacological stimulation using isoform-specific enzyme-linked immunosorbent assays (ELISAs). Mean 24-h levels of 20- and 22-kDa GH were higher in acromegaly and lower in GH deficiency than in normal subjects, with the 20-to-22-kDa ratio not different between the three groups. In normal subjects, 20-kDa GH was secreted in a pulsatile manner throughout the day, with peaks coinciding with those of 22-kDa GH. However, the half-life of 20-kDa GH (18.7 ± 0.8 min) was significantly longer than that of 22-kDa GH (14.7 ± 0.8 min; P < 0.02). Insulin-induced hypoglycemia, androgen, and oral estrogen caused a parallel and proportionate increase in both isoforms. Octreotide suppressed 20-kDa less rapidly than 22-kDa GH in blood. Administration of recombinant 22-kDa GH in normal subjects rapidly reduced the 20-kDa GH levels. In conclusion, 20-kDa GH is cosecreted with and circulates at a constant proportion of 22-kDa GH. The 20-kDa GH level is reduced by administration of exogenous 22-kDa GH, suggesting rapid negative feedback regulation on pituitary release.
androgen; estrogen; deconvolution analysis; insulin-induced hypoglycemia
This article has been cited by other articles:
|
|
 |
|
  M. Bidlingmaier, J. Suhr, A. Ernst, Z. Wu, A. Keller, C. J. Strasburger, and A. Bergmann High-Sensitivity Chemiluminescence Immunoassays for Detection of Growth Hormone Doping in Sports Clin. Chem., March 1, 2009; 55(3): 445 - 453. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Blake, L. M. Brown, M. W. Duncan, S. W. Hunsucker, and S. M. Helmke Estrogen Regulation of the Rat Anterior Pituitary Gland Proteome Exp Biol Med, December 1, 2005; 230(11): 800 - 807. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Hurty and B. Flatland Feline Acromegaly: A Review of the Syndrome J. Am. Anim. Hosp. Assoc., September 1, 2005; 41(5): 292 - 297. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. McHugh, R. T. Park, P. H. Sonksen, and R. I.G. Holt Challenges in Detecting the Abuse of Growth Hormone in Sport Clin. Chem., September 1, 2005; 51(9): 1587 - 1593. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Draghia-Akli and M. L. Fiorotto A new plasmid-mediated approach to supplement somatotropin production in pigs J Anim Sci, January 1, 2004; 82(13_suppl): E264 - 269. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Draghia-Akli, K. K. Cummings, A. S. Khan, P. A. Brown, and R. H. Carpenter Effects of plasmid-mediated growth hormone releasing hormone supplementation in young, healthy Beagle dogs J Anim Sci, September 1, 2003; 81(9): 2301 - 2310. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
