Summary
The effects of sodium valproate (a drug enhancing endogenous gamma aminobutyric acid
(GABA)-ergic activity) and of the GABA analog baclofen (a GABA B receptor agonist)
on serum GH levels was tested in 8 type I diabetic men and 8 normal controls. Sodium
valproate (800 mg) or baclofen (10 mg) were given by mouth at 08.30 h on the experimental
days. Control tests with a placebo were performed on different occasions. Basal GH
levels were similar in controls and diabetic patients. Sodium valproate induced a
7 fold increase in serum GH concentrations in both groups. In contrast, baclofen-induced
GH rise was significantly higher in normal controls (mean peak was 3.4 times higher
than baseline) than in diabetic patients (mean peak was only 2.1 times higher than
basal value). Serum GH levels did not change after placebo administration in any groups.
These data suggest the presence of diabetes-induced alterations of a GABAergic pathway
mediated by B receptors in the control of GH secretion. Alternatively, the data might
indicate a change in diabetic men of other baclofen-sensitive neurotransmissions,
different from GABA.
Key words
Baclofen - Sodium Valproate - Growth Hormone - Diabetes Mellitus
