Endogenous growth hormone (GH)-releasing hormone is required for GH responses to pharmacological stimuli.

Jaffe, Craig A.; DeMott-Friberg, Roberta; Barkan, Ariel L.

doi:10.1172/jci118516

Cited by 88 publications

(73 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The similar results were previouly reported by Jaffe et al [3]. Further, GHRH-Ant significantly inhibited the GH secretion brought about sequential administration of these agents after GHRH injection.…”

Section: Discussionsupporting

confidence: 90%

The Mechanism of Arginine- and Insulin-Induced GH Release in Humans

Hanew¹

2000

Endocr J

View full text Add to dashboard Cite

TO evaluate growth hormone (GH) secretory capacity, GH response to pharmacological stimuli, the spontaneous 24 hr GH secretory profile, urinary GH, plasma IGF-I and IGFBP-3 were employed. As a pharmacological stimuli L-dopa, clonidine, arginine, insulin and glucagon are used widely.It is generally accepted that GH secretion is under the dual control of hypothalamic GHRH and somato-statin (SS). Previously we reported that Ldopa and clonidine stimulate GH secretion through the release of hypothalamic GHRH [1], but it is not clear whether arginine and insulin stimulate GH secretion via the release of GHRH or via the inhibition of SS.It is reported that the second amino acid of GHRH is important for the receptor binding [2]. The amino acids of synthetic [N-Ac-Tyrl-D-Ala2]GRF(1-29) NH2 (GHRH-Ant) are different from human GHRH in the first and second positions, and it exerts a specific antagonistic action on human and rat GHRH receptors [1].In this study GH releasing actions of arginine and insulin were examined by using GHRH-Ant in normal subjects whether these agents stimulate GH secretion via the hypothalmic GHRH release or not. Seven normal adult males (21-30 yr) were examined in this study after obtaining approval from the ethical commitee and informed consent from every subject. In these subjects the following studies were performed: 1) single administration of arginine (0.5 g/kg iv from 0 to 30 min) and insulin test (Insulin Tolerance Test, regular insulin, 0.05 U/kg iv at 0 min) with or without combined administration of GHRH-Ant (800 pg iv from 30 to 120 min), 2) sequential administration of GHRH(1-44)NH2 (100 jig iv at 0 and 120 min). 3) sequential administration of GHRH(1-44)NH2 (100 jig iv at 0 min) and arginine (iv from 120 to 150 min) or insulin test (iv at 120 min) with or without concomitant administration of GHRH-Ant (800 jig iv from 90 to 240 min).Plasma samples were obtained -30, 0 min before and every 30 min until 120 min after the arginine test, and -30, 0mm and 15, 30, 45, 60, 90 and 120 mm after the insulin or GHRH test. Plasma GH was measured in duplicate with a high sensitivity IRMA kit (Daiichi, Tokyo), and the minimal detectable level was 0.006 pg/L, and intra-and inter-assay coefficients of variation were 2.2% and 3.5%, respectively.

show abstract

Section: Discussionsupporting

confidence: 90%

The Mechanism of Arginine- and Insulin-Induced GH Release in Humans

Hanew¹

2000

Endocr J

View full text Add to dashboard Cite

show abstract

“…Measurement of GHRH or SRIH in hypothalamic-pituitary blood is not practical in humans and peripheral measurements of these peptides may not reflect hypothalamic secretion. Our previous studies in humans using a specific antagonist to the GHRH receptor (36,37), as well as physiologic experiments demonstrating concordance between GHRH and GH secretion in sheep (31,32) suggest that GHRH and SRIH in higher mammals likely play roles that are parallel to those found in rats.…”

Section: Table II Comparison Of Parameters Of Gh Secretion and Igfbpmentioning

confidence: 79%

Regulatory mechanisms of growth hormone secretion are sexually dimorphic.

Jaffe

Ocampo-Lim²,

Guo³

et al. 1998

J. Clin. Invest.

Self Cite

211

138

View full text Add to dashboard Cite

Sexually dimorphic growth hormone (GH) secretory pattern is important in the determination of gender-specific patterns of growth and metabolism in rats. Whether GH secretion in humans is also sexually dimorphic and the neuroendocrine mechanisms governing this potential difference are not fully established. We have compared pulsatile GH secretion profiles in young men and women in the baseline state and during a continuous intravenous infusion of recombinant human insulin-like growth factor I (rhIGF-I). During the baseline study, men had large nocturnal GH pulses and relatively small pulses during the rest of the day. In contrast, women had more continuous GH secretion and more frequent GH pulses that were of more uniform size. The infusion of rhIGF-I (10 g/kg/h) potently suppressed both spontaneous and growth hormone-releasing hormone (GHRH)-induced GH secretion in men. In women, however, rhIGF-I had less effect on pulsatile GH secretion and did not suppress the GH response to GHRH. These data demonstrate the existence of sexual dimorphism in the regulatory mechanisms involved in GH secretion in humans.

show abstract

“…In all, these findings may indicate the existence of an extra somatostatin component in the modulatory action of cholinergic drugs on GH release and that the stimulation of GH secretion by pyridostigmine in the human also is dependent upon GHRH action, as shown, albeit inferentially, by the ability of a competitive GHRH antagonist to suppress the increase in GH induced by the AChE inhibitor (17). The purported dual action of pyridostigmine would be best reconciled by the interpretation that pyridostigmine triggers rebound release of GH by suppressing somatostatin secretion, thus unmasking endogenous GHRH tone (18)(19)(20).…”

Section: Cholinergic Mediation: a 'Pure' Antisomatostatin Mechanism?mentioning

confidence: 85%

Cholinergic function and neural control of GH secretion. A critical re-appraisal

Müller

1997

European Journal of Endocrinology

View full text Add to dashboard Cite

Endogenous growth hormone (GH)-releasing hormone is required for GH responses to pharmacological stimuli.

Cited by 88 publications

References 47 publications

The Mechanism of Arginine- and Insulin-Induced GH Release in Humans

The Mechanism of Arginine- and Insulin-Induced GH Release in Humans

Regulatory mechanisms of growth hormone secretion are sexually dimorphic.

Cholinergic function and neural control of GH secretion. A critical re-appraisal

Contact Info

Product

Resources

About