Hexarelin, a novel GHRP-6 analog, counteracts the inhibitory effect of hydrocortisone on growth hormone secretion in acromegaly
| Autor: | Andrea Giustina, Bruno P. Imbimbo, Enrico Bresciani, Giovanna Bugari, Gianni Giustina, Anna Rosa Bussi, Romano Deghenghi |
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| Přispěvatelé: | Giustina, Andrea, Bresciani, E, Bugari, G, Bussi, Ar, Deghenghi, R, Imbimbo, B, Giustina, G. |
| Rok vydání: | 1995 |
| Předmět: |
Adult
Male medicine.medical_specialty Hydrocortisone medicine.medical_treatment Molecular Sequence Data Endogeny chemistry.chemical_compound Endocrinology Bolus (medicine) Internal medicine Acromegaly medicine Humans Amino Acid Sequence GHRP-6 Growth Substances Saline Aged business.industry General Medicine Middle Aged medicine.disease Growth hormone secretion Kinetics Somatostatin chemistry Growth Hormone Female business Oligopeptides medicine.drug |
| Zdroj: | Endocrine Research. 21:569-582 |
| ISSN: | 1532-4206 0743-5800 |
| DOI: | 10.1080/07435809509030474 |
| Popis: | Hexarelin (His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH2) is a GHRP-6 analog with the substitution of D-tryptophan with its 2-methyl derivative. The aim of our study was to ascertain whether hexarelin was able to counteract the glucocorticoid-mediated increase in hypothalamic somatostatin tone and consequent inhibition on serum GH levels in acromegalic patients. Ten patients (5 males, 5 females; age range 27-71 years; BMI range 23.3-35 kg/m2) with active acromegaly underwent: 1) hydrocortisone alone: a bolus iv injection of 100 mg hydrocortisone succinate in 2 mL saline, at time -60 followed by a 120 min iv infusion of 250 mg hydrocortisone succinate in 250 mL saline, from -60 to 60 min; 2) hexarelin+hydrocortisone: a bolus iv injection of hexarelin 100 micrograms, 60 min after initiation of a 2-hour hydrocortisone infusion; 3) hexarelin alone: a bolus iv injection of hexarelin at time 0, 60 min after initiation of a 2-hour saline infusion. The mean GH peak, expressed as percent change with respect to baseline level (mean of -75 and -60 minute samples), after hexarelin (1750 +/- 1157%) did not differ significantly with respect to that observed after hexarelin+hydrocortisone (1120 +/- 770%). After hydrocortisone alone the patients showed a mean decrease in GH levels as compared to baseline levels, of 47 +/- 7%. Our data show that the GH response to hexarelin in acromegaly is resistant to the inhibitor action of an acute and sustained elevation of serum cortisol levels. That hexarelin counteracts the glucocorticoid-mediated inhibition of GH secretion supports the hypothesis of an hexarelin-induced decrease in endogenous somatostatin tone. |
| Databáze: | OpenAIRE |
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