Regulatory Actions of Testosterone on Pulsatile Growth Hormone Secretion in the Human: Studies Using Deconvolution Analysis

1995 ◽  
pp. 40-57 ◽  
Author(s):  
J. D. Veldhuis ◽  
A. Iranmanesh ◽  
A. D. Rogol ◽  
R. J. Urban
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Human Studies ◽  
Deconvolution Analysis ◽  
Regulatory Actions

scholarly journals Overtrained horses alter their resting pulsatile growth hormone secretion

2009 ◽  
Vol 297 (2) ◽  
pp. R403-R411 ◽  
Author(s):  
E. de Graaf-Roelfsema ◽  
P. P. Veldhuis ◽  
H. A. Keizer ◽  
M. M. E. van Ginneken ◽  
K. G. van Dam ◽  
...  
Keyword(s):  
Growth Hormone ◽  
High Speed ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Approximate Entropy ◽  
Underlying Mechanism ◽  
Deconvolution Analysis ◽  
Gh Secretion ◽  
Pulsatility Pattern ◽  
It Training

The influence of intensified and reduced training on nocturnal growth hormone (GH) secretion and elimination dynamics was studied in young (1.5 yr) Standardbred geldings to detect potential markers indicative for early overtraining. Ten horses trained on a treadmill for 32 wk in age-, breed-, and gender-matched fixed pairs. Training was divided into four phases (4, 18, 6, and 4 wk, respectively): 1) habituation to high-speed treadmill trotting, 2) normal training, in which speed and duration of training sessions were gradually increased, 3) in this phase, the horses were divided into 2 groups: control (C) and intensified trained (IT) group. In IT, training intensity, duration, and frequency were further increased, whereas in control these remained unaltered, and 4) reduced training (RT). At the end of phases 2, 3, and 4, blood was sampled overnight every 5 min for 8 h for assessment of GH secretory dynamics using pulse detection, deconvolution analysis, and approximate entropy (ApEn). Intensified training induced overtraining (performance decreased by 19% compared with C), which was associated with an increase in concentration peaks number (3.6 vs. 2.0, respectively), a smaller peak secretion pattern with a prolonged half-life (15.2 vs. 7.3 min, respectively), and an increased ApEn (0.89 vs. 0.49, respectively). RT did not lead to full recovery for the overtrained horses. The increased irregularity of nocturnal GH pulsatility pattern is indicative of a loss of coordinated control of GH regulation. Longer phases of somatostatin withdrawal are hypothesized to be the underlying mechanism for the observed changes in GH pulsatility pattern.

Actions of estrogen on pulsatile, nyctohemeral, and entropic modes of growth hormone secretion

1999 ◽  
Vol 276 (5) ◽  
pp. R1351-R1358 ◽  
Author(s):  
N. Shah ◽  
W. S. Evans ◽  
J. D. Veldhuis
Keyword(s):  
Growth Hormone ◽  
Serum Insulin ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Approximate Entropy ◽  
Thyroid Stimulating Hormone ◽  
Deconvolution Analysis ◽  
Gh Secretion ◽  
Specific Regulation ◽  
Stimulating Hormone

The neuroendocrine mechanisms by which estradiol drives growth hormone (GH) secretion in the human are poorly defined. Here we investigate estrogen’s specific regulation of the 24-h pulsatile, nyctohemeral, and entropic modes of GH secretion in healthy postmenopausal women. Volunteers ( n = 9) received randomly ordered placebo versus estradiol-17β (1 mg micronized steroid twice daily orally) treatment for 7–10 days and underwent blood sampling at 10-min intervals for 24 h to capture GH release profiles quantitated in a high-sensitivity chemiluminescence assay. Pulsatile GH secretion was appraised via deconvolution analysis, nyctohemeral GH rhythms by cosinor analysis, and the orderliness of GH release patterns via the approximate entropy statistic. Mean (±SE) 24-h serum GH concentrations approximately doubled on estrogen treatment (viz., from 0.31 ± 0.03 to 0.51 ± 0.07 μg/l; P = 0.033). Concomitantly, serum insulin-like growth factor-I (IGF-I), luteinizing hormone, and follicle-stimulating hormone concentrations fell, whereas thyroid-stimulating hormone and prolactin levels rose ( P < 0.01). The specific neuroendocrine action of estradiol included 1) a twofold amplified mass of GH secreted per burst, with no significant changes in basal GH release, half-life, pulse frequency, or duration; 2) an augmented amplitude and mesor of the 24-h rhythm in GH release, with no alteration in acrophase; and 3) greater disorderliness of GH release (higher approximate entropy). These distinctive and dynamic reactions to estrogen are consistent with partial withdrawal of IGF-I’s negative feedback and/or accentuated central drive to GH secretion.

Acipimox enhances spontaneous growth hormone secretion in obese women

2004 ◽  
Vol 286 (4) ◽  
pp. R693-R698 ◽  
Author(s):  
Petra Kok ◽  
Madelon M. Buijs ◽  
Simon W. Kok ◽  
Inge H. A. P. van Ierssel ◽  
Marijke Frölich ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Normal Weight ◽  
Control Group ◽  
Time Interval ◽  
Obese Women ◽  
Double Blind ◽  
Deconvolution Analysis ◽  
Gh Secretion

We hypothesized that a high circulating free fatty acid (FFA) concentration is involved in the pathogenesis of hyposomatotropism associated with obesity. To evaluate this hypothesis, 10 healthy premenopausal women (body mass index 33.8 ± 1.0 kg/m2) were studied in the follicular phase of their menstrual cycle at two occasions with a time interval of at least 8 wk, where body weight remained stable. Subjects were randomly assigned to treatment with either acipimox (an inhibitor of lipolysis, 250 mg orally 4 times daily) or placebo in a double-blind crossover design, starting 1 day before admission until the end of the blood sampling period. Blood samples were taken during 24 h with a sampling interval of 10 min for assessment of growth hormone (GH) concentrations, and GH secretion was estimated by deconvolution analysis. Identical methodology was used to study GH secretion in a historical control group of age-matched normal weight women. GH secretion was clearly blunted in obese women (total daily release 66 ± 10 vs. lean controls: 201 ± 23 mU·lVd-1·24 h-1, P = 0.005, where lVd is liter of distribution volume). Acipimox considerably enhanced total (113 ± 50 vs. 66 ± 10 mU·lVd-1·24 h-1, P = 0.02) and pulsatile GH secretion (109 ± 49 vs. 62 ± 30 mU·lVd-1·24 h-1, P = 0.02), but GH output remained lower compared with lean controls. Further analysis did not show any relationship between the effects of acipimox on GH secretion and regional body fat distribution. In conclusion, acipimox unleashes spontaneous GH secretion in obese women. It specifically enhances GH secretory burst mass. This might mean that lowering of systemic FFA concentrations by acipimox modulates neuroendocrine mechanisms that orchestrate the activity of the somatotropic ensemble.

scholarly journals Elevated Growth Hormone Secretory Rate in Premature Infants: Deconvolution Analysis of Pulsatile Growth Hormone Secretion in the Neonate

1992 ◽  
Vol 32 (3) ◽  
pp. 286-290 ◽  
Author(s):  
Nancy M Wright ◽  
Frances J Northington ◽  
John D Miller ◽  
Johannes D Veldhuis ◽  
Alan D Rogol
Keyword(s):  
Growth Hormone ◽  
Premature Infants ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Secretory Rate ◽  
Deconvolution Analysis

scholarly journals Overnight Growth Hormone Secretion in Achondroplasia: Deconvolution Analysis, Correlation with Sleep State, and Changes after Treatment of Obstructive Sleep Apnea

1996 ◽  
Vol 39 (3) ◽  
pp. 547-553 ◽  
Author(s):  
Karen A Waters ◽  
Turkka Kirjavainen ◽  
Mark Jimenez ◽  
Christopher T Cowell ◽  
David O Sillence ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Sleep State ◽  
Deconvolution Analysis ◽  
Obstructive Sleep

THE APPLICATION OF DECONVOLUTION ANALYSIS TO ELUCIDATE THE PULSATILE NATURE OF GROWTH HORMONE SECRETION USING A VARIABLE HALF-LIFE OF GROWTH HORMONE

1990 ◽  
Vol 32 (6) ◽  
pp. 739-747 ◽  
Author(s):  
P. C. HINDMARSH ◽  
D. R. MATTHEWS ◽  
C. BRAIN ◽  
P. J. PRINGLE ◽  
C. G. D. BROOK
Keyword(s):  
Growth Hormone ◽  
Half Life ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Deconvolution Analysis
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