Arginine stimulates growth hormone secretion by suppressing endogenous somatostatin secretion.

  title={Arginine stimulates growth hormone secretion by suppressing endogenous somatostatin secretion.},
  author={J. Alba-Roth and Otto Albrecht M{\"u}ller and Jochen Schopohl and Klaus von Werder},
  journal={The Journal of clinical endocrinology and metabolism},
  volume={67 6},
To determine how arginine (Arg) stimulates GH secretion, we investigated its interaction with GHRH in vivo and in vitro. Six normal men were studied on four occasions: 1) Arg-TRH, 30 g arginine were administered in 500 mL saline in 30 min, followed by an injection of 200 micrograms TRH; 2) GHRH-Arg-TRH, 100 micrograms GHRH-(1-44) were given iv as a bolus immediately before the Arg infusion, followed by 200 micrograms TRH, iv; 3) GHRH test, 100 micrograms GHRH were given as an iv bolus; and 4… 

The decrease in growth hormone (GH) response after repeated stimulation with GH-releasing hormone is partly caused by an elevation of somatostatin tonus.

The decreased GH response to a second GHRH bolus may be partly due to an elevated hypothalamic somatostatin secretion, which can be suppressed by Arg, and it is suggested that the readily available GH pool in the human pituitary may be limited.

Impaired inhibitory effects of somatostatin on growth hormone (GH)-releasing hormone stimulation of GH secretion after short term infusion.

The desensitization to SriH inhibition of GH responses to GHRH after a 6-h SRIH infusion provides evidence of physiological consequences of SRIh receptor down-regulation, and the impaired GH responding to repeated G HRH stimulation are mediated at least in part by enhanced SRI h secretion, which appears independent of a beta-adrenergic mechanism.

Low doses of either intravenously or orally administered arginine are able to enhance growth hormone response to growth hormone releasing hormone in elderly subjects

The results show that the GH response to GHRH in elderly subjects is enhanced even by low iv doses of arginine and by the orally administered amino acid, the lowest effective dose being 8 g, implying that the combined administration of G HRH and ARG may be a useful approach to restore the impaired function of the GH-IGF axis in aging.

IGF-I does not affect the net increase in GH release in response to arginine.

The findings suggest that the negative feedback effect of IGF-I on GH secretion is primarily mediated at the pituitary level and/or at the hypothalamus through a mechanism different from the stimulatory effect of arginine.

Low dose orally administered arginine is able to enhance both basal and growth hormone-releasing hormone-induced growth hormone secretion in normal short children

Results show that a low dose of orally administered ARG is able to enhance the GHRH-induced GH rise with the same extent of a high dose iv administer ARG in normal short children.

Growth hormone (GH) responsiveness to combined administration of arginine and GH-releasing hormone does not vary with age in man.

The results show that the somatotroph response to combined administration of ARG and GHRH does not vary with age, and suggests that an increased somatostatinergic activity may underlie the reduced GH secretion in normal aging.

Endogenous somatostatin is critical in regulating the acute effects of L-arginine on growth hormone and insulin release in mice.

The hypothesis that the primary mechanism by which l-Arg acutely increases GH in vivo is by lowering hypothalamic SST input to the pituitary and not via direct pituitARY effects is supported.

Galanin positively modulates prolactin secretion in normal women

It is demonstrated that in normal women galanin enhances the PRL response to ARG and TRH but fails to modify that induced by dopamine receptor blockade with metoclopramide, and is unlikely that Galanin influences PRL secretion via inhibition of dopaminergic tone.



Growth hormone releasing factor infusion does not sustain elevated GH-levels in normal subjects.

Findings show that GRF infusion or bolus injection in short intervals does not sustain elevated GH-levels, and TRH did not lead to a GH-increase during hpGRF1-44 infusion though Prl and TSH rose normally.


Investigation of the mechanisms by which arginine and L‐dopa cause GH release in humans found that prior GHRH administration abolished the GH response to subsequent G HRH, but this rise was abolished by pretreatment with GHRD.

Growth hormone (GH) release in response to GH-releasing hormone in man is 3-fold enhanced by galanin.

The effect of GHRH in a dose (120 micrograms) thought to produce a maximal GH response was compared with the GH response to insulin-induced hypoglycemia, iv infusion of the hypothalamic neuropeptide

The interrelationship of growth hormone (GH)-releasing factor and somatostatin in generation of the ultradian rhythm of GH secretion.

Support is provided for the hypothesis that GRF and SRIF are secreted tonically from the hypothalamus into the hypophyseal portal blood, and that superimposed upon this steady state release is an additional 3- to 4-h rhythmic surge of each peptide, providing for integration of the ultradian rhythm of GH secretion, as observed in peripheral blood.

Human pancreatic tumor growth hormone-releasing factor: dose-response relationships in normal man.

Human pancreatic GRF selectively stimulates GH release in normal men over a dose range of 0.1-10 micrograms/kg and is an effective probe to investigate the dynamics of GH release.

L-dopa stimulates release of hypothalamic growth hormone-releasing hormone in humans.

A sensitive RIA for human GH-releasing hormone-(1-44)-NH2 [hGHRH-(1-44)-NH2] was developed which allows its measurement in human plasma extracts. The assay did not detect hGHRH-(1-37)-OH or

Circulating growth hormone releasing factor concentrations in normal subjects and patients with acromegaly.

A highly specific and sensitive radioimmunoassay was developed for measuring circulating growth hormone releasing factor (GRF) in human plasma to help elucidate the physiological role(s) of GRF and may also prove useful in differentiating between pituitary and hypothalamic defects in patients with acromegaly.


A highly specific radioimmunoassay has been used to study changes in peripheral human plasma growth hormone releasing factor (GRF) following the ingestion of food and the predominant source of peripheral circulating GRF‐like immunoreactivity may therefore by extrahy‐pothalamic and responds to an oral food stimulus.

Dose-response relationships for the effects of growth hormone-releasing factor-(1-44)-NH2 in young adult men and women.

A dose of 1 micrograms/kg GRF-44 is safe and effective, and would appear to be a reasonable choice for use in studying GH responses in normal subjects of other ages and in patients with disorders of GH secretion.

The arginine provocative test: an aid in the diagnosis of hyposomatotropism.

Comparisons have been made of the secretion of growth hormone (HGH) following the induction of hypoglycemia with insulin and that induced by arginine infusion to determine the reliability of the latter procedure in the diagnosis of disturbances in growth hormone secretion in children and adult patients.