Exogenous growth hormone (hGH) administration in humans attenuates the endogenous growth hormone (GH) response to some pharmacological stimuli; in particular, pretreatment with hGH completely blocks the serum GH response to growth hormone-releasing hormone. In order to evaluate the mechanism(s) whereby opioids induce GH secretion in man, we gave the following treatments to six healthy male volunteers: (a) IV saline; (b) a met-enkephalin analog G-DAMME 250 μg IV as a bolus at time 0': (c) hGH 2 IU as an IV bolus at time -180'; (d) G-DAMME as above, preceded by hGH as above. In our study, G-DAMME stimulated GH secretion both basally (peak 17.9 ± 6.0 ng/ml) and, to a lesser extent, after hGH pretreatment (6.0 ± 2.7 ng/ml). Since in our study G-DAMME was able to partially overcome the inhibitory effect of hGH administration, it is suggested that opioids act through an inhibition of somatostatin release and not through a GHRH-dependent pathway. However, an additional direct effect of hGH on pituitary somatotrophes cannot be excluded.
Exogenous growth hormone (hGH) administration in humans attenuates the endogenous growth hormone (GH) response to some pharmacological stimuli; in particular, pretreatment with hGH completely blocks the serum GH response to growth hormone-releasing hormone. In order to evaluate the mechanism(s) whereby opiods induce GH secretion in man, we gave the following treatments to six healthy male volunteers: (a) IV saline; (b) a met-enkephalin analog G-DAMME 250 micrograms IV as a bolus at time 0'; (c) hGH 2 IU as an IV bolus at time -180'; (d) G-DAMME as above, preceded by hGH as above. In our study, G-DAMME stimulated GH secretion both basally (peak 17.9 +/- 6.0 ng/ml) and, to a lesser extent, after hGH pretreatment (6.0 +/- 2.7 ng/ml). Since in our study G-DAMME was able to partially overcome the inhibitory effect of hGH administration, it is suggested that opioids act through an inhibition of somatostatin release and not through a GHRH-dependent pathway. However, an additional direct effect of hGH on pituitary somatotrophes cannot be excluded. Z9 2
Effect of exogenous growth hormone administration on endogenous growth hormone secretion induced by a met-enkephalin analog / Fanciulli, Giuseppe; Oliva, O; Tomasi, Paolo; Pala, A; Bertoncelli, A; Dettori, A; Delitala, Giuseppe. - In: EUROPEAN JOURNAL OF ENDOCRINOLOGY. - ISSN 0804-4643. - 134:1(1996), pp. 73-76.
Effect of exogenous growth hormone administration on endogenous growth hormone secretion induced by a met-enkephalin analog
FANCIULLI, Giuseppe;TOMASI, Paolo;DELITALA, Giuseppe
1996-01-01
Abstract
Exogenous growth hormone (hGH) administration in humans attenuates the endogenous growth hormone (GH) response to some pharmacological stimuli; in particular, pretreatment with hGH completely blocks the serum GH response to growth hormone-releasing hormone. In order to evaluate the mechanism(s) whereby opioids induce GH secretion in man, we gave the following treatments to six healthy male volunteers: (a) IV saline; (b) a met-enkephalin analog G-DAMME 250 μg IV as a bolus at time 0': (c) hGH 2 IU as an IV bolus at time -180'; (d) G-DAMME as above, preceded by hGH as above. In our study, G-DAMME stimulated GH secretion both basally (peak 17.9 ± 6.0 ng/ml) and, to a lesser extent, after hGH pretreatment (6.0 ± 2.7 ng/ml). Since in our study G-DAMME was able to partially overcome the inhibitory effect of hGH administration, it is suggested that opioids act through an inhibition of somatostatin release and not through a GHRH-dependent pathway. However, an additional direct effect of hGH on pituitary somatotrophes cannot be excluded.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
