Tripartite neuroendocrine activation of the human growth hormone (GH) axis in women by continuous 24-hour GH-releasing peptide infusion: pulsatile, entropic, and nyctohemeral mechanisms.

Shah N, Evans WS, Bowers CY, Veldhuis JD

The Journal of clinical endocrinology and metabolism1 Jun 1999Cited by 28 (Europe PMC)

PMID10372723DOI10.1210/jcem.84.6.5687PepBankPUB-10372723

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study18

18 results from studies that gave the peptide. 18 results from people.

01HumanRandomized controlled trialActivity measurement
In postmenopausal women, 24-h GHRP‑2 infusion raised mean 24-h serum GH 7.7-fold versus saline.
In plain wordsIn postmenopausal women, a 24-hour GHRP‑2 infusion raised average growth hormone about 7.7 times compared with saline.
Peptide
GHRP-2
Outcome
Increase24-h mean serum GH
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Measurements
Mean 24-h serum GH
2.4 microg/L
GHRP-2
Mean 24-h serum GH
0.32 microg/L
saline
Source sentences
Summary
Statistical analysis revealed that GHRP-2 elicited a 7.7-fold increase in (24-h) mean serum (+/-SEM) GH concentrations, viz. from 0.32 +/- 0.042 (saline) to 2.4 +/- 0.34 microg/L (GHRP-2; P = 0.0006).
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272301
02HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 infusion raised GH secretory burst mass 7.1-fold versus saline.
In plain wordsIn postmenopausal women, GHRP‑2 made each growth hormone burst about 7.1 times larger than with saline.
Peptide
GHRP-2
Outcome
IncreaseGH secretory burst mass
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Measurements
GH secretory burst mass
6.3 microg/L
GHRP-2
GH secretory burst mass
0.87 microg/L
saline
Source sentences
Summary
This occurred via markedly stimulated pulsatile GH release, namely a 7.1-fold augmentation of GH secretory burst mass: 0.87 +/- 0.18 (control) vs. 6.3 +/- 1.3 microg/L (GHRP-2; P = 0.0038).
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272302
03HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 infusion raised GH secretory burst amplitude 10-fold versus saline.
In plain wordsIn postmenopausal women, GHRP‑2 made growth hormone bursts about 10 times higher than with saline.
Peptide
GHRP-2
Outcome
IncreaseGH secretory burst amplitude
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
Enhanced GH pulse mass reflected a commensurate 10-fold (P = 0.023) rise in GH secretory burst amplitude [maximal GH secretory rate (micrograms per L/min) attained within a secretory pulse] with no prolongation in event duration.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272303
04HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 infusion did not prolong GH pulse event duration.
In plain wordsIn postmenopausal women, GHRP‑2 did not make growth hormone pulses last longer than with saline.
Peptide
GHRP-2
Outcome
No significant changeGH pulse event duration
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
with no prolongation in event duration.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272304
05HumanRandomized controlled trialActivity measurement
In postmenopausal women, GH burst frequency was invariant of GHRP‑2 treatment.
In plain wordsIn postmenopausal women, GHRP‑2 did not change how often growth hormone bursts occurred.
Peptide
GHRP-2
Outcome
No significant changeGH burst frequency
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
GH burst frequency, interpulse interval, and calculated GH half-life were all invariant of GHRP-2 treatment.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272305
06HumanRandomized controlled trialActivity measurement
In postmenopausal women, the GH interpulse interval was invariant of GHRP‑2 treatment.
In plain wordsIn postmenopausal women, GHRP‑2 did not change the time between growth hormone bursts.
Peptide
GHRP-2
Outcome
No significant changeGH interpulse interval
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
GH burst frequency, interpulse interval, and calculated GH half-life were all invariant of GHRP-2 treatment.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272306
07HumanRandomized controlled trialActivity measurement
In postmenopausal women, calculated GH half-life was invariant of GHRP‑2 treatment.
In plain wordsIn postmenopausal women, GHRP‑2 did not change how fast growth hormone cleared from the blood.
Peptide
GHRP-2
Outcome
No significant changeGH half-life
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
GH burst frequency, interpulse interval, and calculated GH half-life were all invariant of GHRP-2 treatment.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272307
08HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 augmented deconvolution-estimated interpulse (basal) GH secretion by 4.5-fold.
In plain wordsIn postmenopausal women, GHRP‑2 raised the steady background growth hormone release about 4.5 times.
Peptide
GHRP-2
Outcome
IncreaseInterpulse (basal) GH secretion
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
Concurrently, as detected in the ultrasensitive GH assay, GHRP-2 augmented deconvolution-estimated interpulse (basal) GH secretion by 4.5-fold (P = 0.025).
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272308
09HumanRandomized controlled trialActivity measurement
In postmenopausal women, the approximate entropy of 24-h GH profiles rose significantly during GHRP‑2 infusion, meaning more irregular GH release.
In plain wordsIn postmenopausal women, GHRP‑2 made growth hormone release patterns more irregular than with saline.
Peptide
GHRP-2
Outcome
IncreaseApproximate entropy of 24-h GH profiles
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Measurements
Approximate entropy
0.824
GHRP-2
Approximate entropy
0.592
saline
Source sentences
Summary
The approximate entropy of 24-h serum GH concentration profiles rose significantly during GHRP-2 infusion; i.e. from 0.592 +/- 0.073 (saline) to 0.824 +/- 0.074 (GHRP-2; P = 0.0011), signifying more irregular or disorderly GH release patterns during secretagogue stimulation.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272309
10HumanRandomized controlled trialActivity measurement
In postmenopausal women, the GH rhythm acrophase was significantly earlier (daytime) during GHRP‑2 infusion than during saline.
In plain wordsIn postmenopausal women, GHRP‑2 moved the daily peak of growth hormone to earlier in the day compared with saline.
Peptide
GHRP-2
Outcome
Not applicableAcrophase of 24-h GH rhythm
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
Cosinor analysis of 24-h GH rhythms disclosed a significantly earlier (daytime) acrophase at 2138 h (+/- 140 min) during GHRP-2 stimulation vs. 0457 h (+/-42 min) during saline infusion (P = 0.013).
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272310
11HumanRandomized controlled trialActivity measurement
In postmenopausal women, the cosinor amplitude of the 24-h GH rhythm rose 6-fold during GHRP‑2 infusion.
In plain wordsIn postmenopausal women, GHRP‑2 made the daily growth hormone rhythm about 6 times stronger than with saline.
Peptide
GHRP-2
Outcome
IncreaseCosinor amplitude of 24-h GH rhythm
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
Concomitantly, the cosinor amplitude rose 6-fold
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272311
12HumanRandomized controlled trialActivity measurement
In postmenopausal women, the mesor (cosine mean) of the 24-h GH rhythm rose 5-fold during GHRP‑2 infusion.
In plain wordsIn postmenopausal women, GHRP‑2 raised the average growth hormone level of the daily rhythm 5 times.
Peptide
GHRP-2
Outcome
IncreaseMesor of 24-h GH rhythm
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
and the mesor (cosine mean) rose 5-fold (P = 0.003).
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272312
13HumanRandomized controlled trialActivity measurement
In postmenopausal women, fasting plasma IGF-I rose by 102 microg/L during GHRP‑2 infusion versus -11 microg/L during saline.
In plain wordsIn postmenopausal women, GHRP‑2 raised IGF-I in the blood, compared with saline.
Peptide
GHRP-2
Outcome
IncreaseFasting plasma IGF-I change
Study
n = 7
Comparator
Saline
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Measurements
IGF-I change
102 microg/L
GHRP-2
IGF-I change
−11 microg/L
saline
Source sentences
Summary
Fasting (0800 h) plasma insulin-like growth factor (IGF-I) concentrations rose by -11 +/- 12 microg/L during saline infusion and by 102 +/- 18 microg/L during GHRP-2 infusion (P = 0.0036).
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272313
14HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 infusion did not modify pooled 24-h serum LH.
In plain wordsIn postmenopausal women, GHRP‑2 did not change LH levels.
Peptide
GHRP-2
Outcome
No significant change24-h serum LH
Study
n = 7
Comparator
Saline
Outcome group
Sex hormones and fertility · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
GHRP-2 infusion did not modify (24-h pooled) serum LH, FSH, or TSH concentrations
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272314
15HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 infusion did not modify pooled 24-h serum FSH.
In plain wordsIn postmenopausal women, GHRP‑2 did not change FSH levels.
Peptide
GHRP-2
Outcome
No significant change24-h serum FSH
Study
n = 7
Comparator
Saline
Outcome group
Sex hormones and fertility · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
GHRP-2 infusion did not modify (24-h pooled) serum LH, FSH, or TSH concentrations
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272315
16HumanRandomized controlled trialActivity measurement
In postmenopausal women, GHRP‑2 infusion did not modify pooled 24-h serum TSH.
In plain wordsIn postmenopausal women, GHRP‑2 did not change TSH levels.
Peptide
GHRP-2
Outcome
No significant change24-h serum TSH
Study
n = 7
Comparator
Saline
Outcome group
Thyroid function · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
GHRP-2 infusion did not modify (24-h pooled) serum LH, FSH, or TSH concentrations
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272316
17HumanRandomized controlled trialSafety outcome
In postmenopausal women, GHRP‑2 infusion minimally increased pooled daily prolactin (P < 0.05).
In plain wordsIn postmenopausal women, GHRP‑2 raised prolactin slightly compared with saline.
Peptide
GHRP-2
Outcome
Increase24-h serum prolactin
Study
n = 7
Comparator
Saline
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Measurements
Daily PRL
12 microg/L
GHRP-2
Daily PRL
6.8 microg/L
saline
Source sentences
Summary
minimally increased serum (pooled) daily PRL (6.8 +/- 0.83 vs. 12 +/- 1.2 microg/L; P < 0.05)
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272317
18HumanRandomized controlled trialSafety outcome
In postmenopausal women, GHRP‑2 infusion minimally increased pooled daily cortisol (P < 0.05).
In plain wordsIn postmenopausal women, GHRP‑2 raised cortisol slightly compared with saline.
Peptide
GHRP-2
Outcome
Increase24-h serum cortisol
Study
n = 7
Comparator
Saline
Outcome group
Stress hormones · Endocrine and hormones
Studied dose
1 microg/kg x h · intravenous · 24 hoursAs given in this study (human).
Source sentences
Summary
cortisol (5.3 +/- 0.59 to 7.0 +/- 0.74; P < 0.05) concentrations.
1 context sentence(design, population, supporting numbers)
Summary · context
To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean s…
Report a problemFND-1037272318

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Version 2Current
13 Oct 2026, 21:44 UTC
Study results updated
Version 1
13 Oct 2026, 16:31 UTC
First added · source update from Europe PMC

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