HANEW, K., SASAKI, A. and YOSHINAGA, K.
Evidence for Endogenous Dopaminergic Control of GH Release in Man. Tohoku J. exp. Med., 1981,
135 (1), 103-108 - In order to determine whether or not there is a tonic dopamine (DA) control of GH release, the effect of an anti-dopaminergic agent, sulpiride, on GH secretion was studied in 12 normal subjects. After the administration of sulpiride, serum concentrations of sulpiride reached a peak value (1.93±0.1 μg/ml, mean±S.E.M.,
n=6) at 15min and then showed a gradual decrease. Concomitantly, mean plasma prolactin (PRL) showed a rapid elevation, with a peak value of 161.9±11.5ng/ml at 30min, followed by a gradual decrease. Even at 180min after sulpiride injection, the plasma PRL was still 9 times higher than the initial level (
p<0.005). Within 90min after the injection, 12 subjects showed a minimal but significant decrease in GH (from 0.78±0.17 to 0.32±0.03ng/ml,
p<0.02). After another 90min, the plasma GH level increased and the mean peak value (8.1±2.7ng/ml) at 180min was significantly higher than the initial value (
p<0.02). From these observations, it was suggested that sulpiride inhibited the endogenous DA activity over 180min, and that the GH decrease within 90min was due to a suppression of endogenous DA activity. Factors other than DA, however, might be considered for the GH increase after 90min.
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