Effect of 15-day treatment with growth-hormone-releasing hormone alone or combined with different doses of arginine on the reduced somatotrope responsiveness to the neurohormone in normal aging

1995 ◽  
Vol 132 (1) ◽  
pp. 32-36 ◽  
Author(s):  
E Ghigo ◽  
GP Ceda ◽  
R Valcavi ◽  
S Goffi ◽  
M Zini ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Day Treatment ◽  
Normal Aging ◽  
Prolonged Treatment ◽  
Elderly Subjects ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Group A ◽  
Group B ◽  
Different Doses

Ghigo E, Ceda GP, Valcavi R, Goffi S, Zini M, Mucci M, Valenti G, Muller EE, Camanni F. Effect of 15-day treatment with growth hormone-releasing hormone alone or combined with different doses of arginine on the reduced somatotrope responsiveness to the neurohormone in normal aging. Eur J Endocrinol 1995;132:32–6. ISSN 0804–4643 It is well known that both spontaneous and growth hormone-releasing hormone (GHRH)-stimulated GH secretion undergo an age-related decrease; in addition, there is supportive evidence that the GH hyposecretory state of aging is of hypothalamic origin. The aims of the study in 35 normal elderly subjects (20 males and 15 females aged 65–89 years) were to verify whether the low somatotrope responsiveness to GHRH (1 μg/kg) can be primed by a daily GHRH treatment and whether the potentiating effect of both high intravenous (0.5 g/kg) and low oral (8 g) doses of arginine (ARG) on GH response to GHRH is maintained with time. In group A (N = 14) the GH response to GHRH on day 1 (AUC: 373.5 ± 78.5 μg·1−1·h−1) was unchanged after 7 (3720 ± 38 μg·1−1·h−1) and 15 days (377.9 ± 63.8 μg·1−1·h−1) of daily GHRH administration. In group B (N = 6) the GH response to GHRH co-administered with iv ARG on day 1 (1614.2 ± 146.2 μg · 1−1 · h−1) was higher (p < 0.05) than that of GHRH alone (group A) and persisted unchanged after 7 (1514.7±366.5 μg·1−1·h−1) and 15 days (1631.7 ± 379.1 μg · 1−1 · h−1) of treatment. In group C (N = 15) the GH response to GHRH co-administered with oral ARG on day 1 (950.6 ± 219.4 μg·1−1 · h−1) was higher (p < 0.03) than that of GHRH alone (group A) but lower (p < 0.05) than that to GHRH plus iv ARG (group B). It was unchanged after 7 (816.2 ± 208.5 μg·1−1 · h−1) and 15 days (760.4 ± 165.0 μg · 1−1· h−1) of treatment; these responses were still higher (p < 0.05) than that to GHRH alone. Insulin-like growth factor I levels were not modified by any of the treatments. In conclusion, our results demonstrate that in normal aging the low somatotrope responsiveness to GHRH is not improved by prolonged treatment with the neurohormone but it is enhanced by the combined treatment with ARG and this effect does not vanish after a 15-day treatment period. The effect of ARG is present even after a low oral dose, although less markedly than after a high intravenous dose. F Camanni, Divisione di Endocrinologia, Ospedale Molinette, C. so Dogliotti 14, 10126 Torino, Italy

THERAPEUTICAL DOSES OF SALBUTAMOL INHIBIT THE SOMATOTROPIC RESPONSIVENESS TO GROWTH HORMONE-RELEASING HORMONE IN ASTHMATIC CHILDREN

PEDIATRICS ◽  
1994 ◽  
Vol 94 (2) ◽  
pp. 262-263
Author(s):  
Hemalini Mehta ◽  
Robert F. Lemanske
Keyword(s):  
Growth Hormone ◽  
Systemic Disease ◽  
Forced Expiratory Volume ◽  
Growth Hormone Releasing Hormone ◽  
Assay Sensitivity ◽  
Releasing Hormone ◽  
Children With Asthma ◽  
Group A ◽  
Study Population ◽  
Group B

Purpose of the Study. To determine the effects of therapeutic β2 agonists (specifically salbutamol) on growth hormone (GH) response to growth hormone releasing hormone (GHRH) in children with asthma. Study Population. Fifteen prepubertal children with asthma, ages 6-11 (average age of 9) with normal or normal short stature were studied. Those with an endocrine abnormality, nutritional deficiency, psychological deprivation, or other systemic disease were excluded. Only those children with known bronchial asthma, who showed a 15% decrease of the 1-second forced expiratory volume (FEV1) with methacholine challenge were included. All patients were asymptomatic, and had not experienced an asthma exacerbation, respiratory infection or allergen exposure in the month preceding the study. No child was on medications. Methods. Subjects were divided into two groups. Both groups had baseline GH response to GHRH determined. After an overnight fast, GH levels were obtained the following morning at -60, 0, and then every 15 minutes until 120 minutes after GHRH administration. Two days following this, Group A received salbutamol (0.125 mg/kg) orally at -60 minutes and GH response to GHRH was remeasured. Group B received aerosolized salbutamol (2 mg over 15 minutes) (details of administration were not specified by the authors). All serum GH levels were measured in duplicate by immunoradiometric assay (sensitivity of 0.1 µg/L). Findings. Basal GH levels were similar in both groups. Orally administered salbutamol (Group A) markedly inhibited GH response to GHRH (peak of 3.7 ± 0.6 vs. 18.6 ± 4.7 g/L). Inhaled salbutamol (Group B), although blunting the GHRH-induced GH response, did so to a lesser extent (peak of 20.0 ± 7.5 vs. 35.8 ± 9.4 g/L, P &lt; .02).

Effect of cholinergic tone on growth hormone-releasing hormone-induced secretion of growth hormone in normal aging

1992 ◽  
Vol 4 (3) ◽  
pp. 231-237 ◽  
Author(s):  
Massimo Giusti ◽  
G. Marini ◽  
P. Sessarego ◽  
F. Peluffo ◽  
S. Valenti ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Normal Aging ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Cholinergic Tone

Growth hormone-releasing activity of growth hormone-releasing peptide-6 is maintained after short-term oral pretreatment with the hexapeptide in normal aging

1994 ◽  
Vol 131 (5) ◽  
pp. 499-503 ◽  
Author(s):  
E Ghigo ◽  
E Arvat ◽  
G Rizzi ◽  
S Goffi ◽  
S Grottoli ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Oral Administration ◽  
Effective Dose ◽  
Elderly Women ◽  
Normal Aging ◽  
Prolonged Treatment ◽  
Elderly Subjects ◽  
Short Term ◽  
Short Term Treatment ◽  
Igf I

Ghigo E, Arvat E, Rizzi G, Goffi S, Grottoli S, Mucci M, Boghen MF, Camanni F. Growth hormonereleasing activity of growth hormone-releasing peptide-6 is maintained after short-term oral pretreatment with the hexapeptide in normal aging. Eur J Endocrinol 1994;131:499–503. ISSN 0804–4643 The reduced activity of the growth hormone (GH)–insulin-like growth factor I (IGF-I) axis in aging may contribute to changes in body composition. As this GH insufficiency is due to hypothalamic pathogenesis, the availability of GH-releasing peptides (GHRPs), such as GHRP-6 (His-d-Trp-Ala-Trp-d-Phe-Lys-NH2) which is active even after oral administration, might be useful to restore it. The aim of our study was to verify the effectiveness of oral administration of GHRP-6 in normal elderly subjects and to investigate whether its GH-releasing activity is maintained or vanishes after short-term oral treatment. Seven normal elderly women (aged 65–82 years) were studied. The effect of oral administration of 300 μg/kg GHRP-6 on GH secretion was investigated before and after 4 days of treatment with the hexapeptide given twice daily. The GH response to the maximal effective dose of GHRH (1 μg/kg iv) also was studied. Before treatment, oral administration of 300 μg/kg GHRP-6 elicited a clear GH rise (peak 10.7 ± 3.3 μg/l; AUC 353.1 ± 90.6 μg·l−1·h−1). which was significantly higher (p < 0.01) than that induced by intravenous GHRH (peak 5.1 ± 1.5 μg/l; AUC 106.5 ±43.9 μg · l−1·h−1). After 4 days of treatment with GHRP-6, the GH response to the hexapeptide was maintained, with a trend towards an increase (peak 16.8 ± 2.9 μg/l; AUC 499.8 ± 107.2 μg·l−1·h−1). The IGF-I levels were not increased significantly after treatment (77.1 ± 8.4 vs 84.1 ± 12.2 μg/l). In conclusion, our results demonstrate that, in aging, oral GHRP-6 administration elicits a GH response that is higher than the maximal effective dose of intravenous GHRH and that the effect of the hexapeptide does not vanish after short-term treatment. More prolonged treatment and/or more frequent administrations of GHRP-6 are likely needed to increase IGF-I levels. F Camanni, Division of Endocrinology, Department of Pathophysiology, Ospedale Molinette, C.so Dogliotti 14, 10126 Torino, Italy

scholarly journals Polyethylene glycol-conjugated growth hormone-releasing hormone is long acting and stimulates GH in healthy young and elderly subjects

2005 ◽  
Vol 153 (2) ◽  
pp. 249-256 ◽  
Author(s):  
A Munafo ◽  
T X Q Nguyen ◽  
O Papasouliotis ◽  
H Lécuelle ◽  
A Priestley ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Polyethylene Glycol ◽  
Serum Insulin ◽  
Repeated Administration ◽  
The Elderly ◽  
Elderly Subjects ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Young Subjects ◽  
Long Acting

Objective: The clinical use of growth hormone-releasing hormone (GHRH) is limited by its short half-life. Polyethylene glycol-conjugated GHRH (PEG-GHRH) was developed to provide increased stability compared with the currently available GHRH(1–29). This study aimed to evaluate the safety, tolerability and pharmacodynamics of PEG-GHRH. Design: PEG-GHRH was administered by subcutaneous injection to young healthy men (n = 12) and elderly men and women (aged > 60 years; n = 20). Results: In both groups, administration of PEG-GHRH generated a clear increase in circulating GH compared with placebo. Following single-dose (0.25, 0.5, 2 or 4 mg) administration to young subjects, the effect persisted for 12 h, but a sustained increase was observed on repeated administration to the elderly. Serum insulin-like growth factor-I also increased in response to PEG-GHRH treatment. Injection-site reactions were more frequent with PEG-GHRH compared with placebo, but these were mild and transient; other adverse events were similar to those observed after placebo. Some impairment of glucose tolerance was observed in the elderly following repeated administration of PEG-GHRH. Antibodies to GHRH were not observed. Conclusions: PEG-GHRH offers the possibility of less frequent dosing compared with GHRH. This possibility deserves further clinical testing.

Growth Hormone-Releasing Hormone and Growth Hormone Secretagogues in Normal Aging

Endocrine ◽  
2003 ◽  
Vol 22 (1) ◽  
pp. 41-48 ◽  
Author(s):  
George R. Merriam ◽  
Robert S. Schwartz ◽  
Michael V. Vitiello
Keyword(s):  
Growth Hormone ◽  
Normal Aging ◽  
Growth Hormone Releasing Hormone ◽  
Growth Hormone Secretagogues ◽  
Releasing Hormone
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