Acute effects of a single administration of dexamethasone on basal and growth hormone-releasing hormone stimulated GH secretion in acromegaly

1994 ◽  
Vol 40 (2) ◽  
pp. 187-191
Author(s):  
Marco Losa ◽  
Maura Arosio ◽  
Alberto Cusin ◽  
Orietta Biella ◽  
Eva Palmieri ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Single Administration ◽  
Growth Hormone Releasing Hormone ◽  
Acute Effects ◽  
Releasing Hormone ◽  
Gh Secretion

Growth hormone-releasing hormone in the diagnosis and treatment of growth hormone deficient children

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S123-S129
Author(s):  
R.J.M. ROSS ◽  
A. GROSSMAN ◽  
G.M. BESSER ◽  
M.O. SAVAGE
Keyword(s):  
Growth Hormone ◽  
Linear Growth ◽  
Gh Deficiency ◽  
Venous Blood ◽  
Alternative Therapy ◽  
Normal Subjects ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Depot Preparations

ABSTRACT A growth hormone-releasing hormone (GHRH) has recently been extracted and synthesised, and appears to be identical to human hypothalamic GHRH. Immunoreactive GHRH is found in the venous blood of normal subjects and GH-deficient children, but is probably not hypothalamic in origin and therefore not important in GH regulation. GHRH is a potent specific stimulator of GH secretion in man, and provides a valuable diagnostic test in differentiating hypothalamic from pituitary causes of GH deficiency. Preliminary data suggests that GHRH may promote linear growth in some GH deficient children. GHRH may well prove an important alternative therapy for GH deficient children especially if depot preparations or intranasal administration prove effective.

scholarly journals Molecular evolution of the growth hormone-releasing hormone/pituitary adenylate cyclase-activating polypeptide gene family. Functional implication in the regulation of growth hormone secretion

2000 ◽  
Vol 25 (2) ◽  
pp. 157-168 ◽  
Author(s):  
M Montero ◽  
L Yon ◽  
S Kikuyama ◽  
S Dufour ◽  
H Vaudry
Keyword(s):  
Growth Hormone ◽  
Molecular Evolution ◽  
Adenylate Cyclase ◽  
Gene Family ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Pituitary Adenylate Cyclase

Growth hormone-releasing hormone (GHRH) and pituitary adenylate cyclase-activating polypeptide (PACAP) belong to the same superfamily of regulatory neuropeptides and have both been characterized on the basis of their hypophysiotropic activities. This review describes the molecular evolution of the GHRH/PACAP gene family from urochordates to mammals and presents the hypothesis that the respective roles of GHRH and PACAP in the control of GH secretion are totally inverted in phylogenetically distant groups of vertebrates. In mammals, GHRH and PACAP originate from distinct precursors whereas, in all submammalian taxa investigated so far, including birds, amphibians and fish, a single precursor encompasses a GHRH-like peptide and PACAP. In mammals, GHRH-containing neurons are confined to the infundibular and dorsomedial nuclei of the hypothalamus while PACAP-producing neurons are widely distributed in hypothalamic and extrahypothalamic areas. In fish, both GHRH- and PACAP-immunoreactive neurons are restricted to the diencephalon and directly innervate the adenohypophysis. In mammals and birds, GHRH plays a predominant role in the control of GH secretion. In amphibians, both GHRH and PACAP are potent stimulators of GH release. In fish, PACAP strongly activates GH release whereas GHRH has little or no effect on GH secretion. The GHRH/PACAP family of peptides thus provides a unique model in which to investigate the structural and functional facets of evolution.

Growth hormone response to growth hormone-releasing hormone (GHRH), insulin, clonidine and arginine after GHRH pretreatment in obese children: evidence of somatostatin increase?

1995 ◽  
Vol 132 (6) ◽  
pp. 716-721 ◽  
Author(s):  
Cecilia Volta ◽  
Sergio Bernasconi ◽  
Lorenzo lughetti ◽  
Lucia Ghizzoni ◽  
Maurizio Rossi ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Normal Weight ◽  
Growth Hormone Response ◽  
Growth Hormone Releasing Hormone ◽  
Hormone Response ◽  
Obese Children ◽  
Normal Children ◽  
Insulin Hypoglycemia ◽  
Releasing Hormone ◽  
Gh Secretion

Volta C. Bernasconi S, lughetti L, Ghizzoni L, Rossi M, Costa M, Cozzini A. Growth hormone response to growth hormone-releasing hormone (GHRH), insulin, clonidine and arginine after GHRH pretreatment in obese children: evidence of somatostatin increase? Eur J Endocrinol 1995; 132:716–21. ISSN 0804–4643 To clarify the possible neuroendocrine mechanisms underlying the impairment in growth hormone (GH) secretion present in obesity, the GH response to GH-releasing hormone (GHRH, N = 6), insulin hypoglycemia (N = 6), clonidine (N = 7) and arginine (N = 8) after GHRH pretreatment (1 μg/kg iv 2 h before the tests) was evaluated in 27 obese peripubertal children and in a group of normal-weight short-normal children (N = 26). Growth hormone-releasing hormone pretreatment and all further stimuli elicited a statistically significant GH response in both obese and short-normal children; in the latter group arginine did not induce a significant GH response. No differences were found among the GH responses after the second stimuli in obese children, while in short-normal children the arginine peak and area values were lower than after GHRH and clonidine. Comparison between the two groups showed similar baseline but higher stimulated GH levels in normal-weight children after all tests except ariginine, after which no difference was present. In conclusion, the neuroregulation of GH release seems to be similar qualitatively in normal-weight and obese youngsters; the different behavior observed after arginine, which is supposed to act through somatostatin inhibition, might be due to a chronic increase in somatostatinergic tone responsible for the lower stimulated GH levels in obesity. Sergio Bernasconi, Clinica Pediatrica, Via Gransci 14, 43100 Parma, Italy

Pyridostigmine partially reverses dexamethasone-induced inhibition of the growth hormone response to growth hormone-releasing hormone

1992 ◽  
Vol 134 (3) ◽  
pp. 513-517 ◽  
Author(s):  
P. J. Trainer ◽  
J. M. W. Kirk ◽  
M. O. Savage ◽  
A. B. Grossman ◽  
G. M. Besser
Keyword(s):  
Growth Hormone ◽  
Area Under The Curve ◽  
Random Order ◽  
Suppressive Effect ◽  
Wilcoxon Test ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Site Of Action ◽  
Oral Glucocorticoids

ABSTRACT The GH response to insulin-induced hypoglycaemia and growth hormone-releasing hormone (GHRH) has been shown to be impaired in subjects with Cushing's syndrome and in healthy volunteers given oral glucocorticoids. Pyridostigmine is an anticholinesterase that stimulates GH secretion, probably by inhibition of hypothalamic somatostatin secretion. This work was designed to study the site of action of glucocorticoids in inhibiting the secretion of GH. Eight healthy male volunteers were studied on three occasions in random order. They took 2 mg oral dexamethasone or placebo at precisely 6-hourly intervals for 48 h before receiving 120 mg oral pyridostigmine or placebo, followed 60 min later by GHRH (100 μg) i.v. Samples for measuring GH were obtained at 15 min intervals for 2 h. The 'area under the curve' (AUC) for each of the treatments was significantly different: dexamethasone–pyridostigmine–GHRH (mean ± s.e.m., 1938 ± 631 mU/min per 1), dexamethasone–placebo–GHRH (634 ±211) and placebo–placebo–GHRH (4267 ± 1183) (P<0·02, Wilcoxon test). In conclusion, dexamethasone given for 48 h significantly inhibited the AUC for GH following treatment with GHRH. However, pretreatment with pyridostigmine significantly reversed the inhibition although this was still partial. Our data suggested that this short-term suppressive effect of dexamethasone was independent of GHRH, and most probably relates to stimulation of the release of somatostatin. Journal of Endocrinology (1992) 134, 513–517

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