GROWTH HORMONE RESPONSES TO PYRIDOSTIGMINE IN NORMAL ADULTS AND IN NORMAL AND SHORT CHILDREN

Publisher Website
Google Scholar
Abstract
There is evidence indicating that the cholinergic system positively modulates GH release probably by inhibiting somatostatinergic tone. In the present study, the effects of cholinergic enhancement by pyridostigmine, (PD), a cholin‐esterases inhibitor, on GH release in normal adults (n= 14) (NA) and in both normal (n = 5) (NC) and short children (n = 19) (SC) with familial short stature (n =7) or constitutional growth delay (n= 12) were studied. In SC the insulin hypoglycaemia (IH)‐induced GH increase was also studied. In both NC and SC 60 mg orally PD induced a significant GH increase with mean peak at 90 min (mean ± SEM 11.0 ± 2.2 ng/ml in NC and 11.2 ± 2.3 ng/ml in SC). The GH areas under response curve (AUC) were 379.3 ± 76.6 and 327.8 ±43.2 ng/ml/h in NC and SC respectively. In NA 120 mg orally PD induced a significant GH increase with mean peak at 120 min (5.1 ± 11 ng/ml) which was significantly lower (P < 0.05) than that observed in both NC and SC. This statistical difference was strengthened by evaluating AUC (NA: 205.6 ± 33.7 ng/ml/h, P < 0.05 vs NC and SC). The correlation of drug dosage with body area ruled out that this difference could be related to the different PD dose in adults and children. In SC, IH induced a GH increase significantly lower than that observed after PD (GH peak 7.8 ± 0.6 vs 16.4 ± 1.9 ng/ml P<0.001). Our data show that cholinergic enhancement by PD induces a higher GH increase in both normal and short children than that observed in adults. This could be related to a variation of somatostatinergic tone. The higher PD‐induced GH response compared to the IH‐induced one indicates that PD test may be considered a more potent GH provocative stimulus than insulin hypoglycaemia.

This publication has 13 references indexed in Scilit: