PYRIDOSTIGMINE INDUCED GROWTH-HORMONE RELEASE IN MANIA - FOCUS ON THECHOLINERGIC SOMATOSTATIN SYSTEM

OBJECTIVE The release of growth hormone (GH) from the anterior pituita ry is partly under cholinergic control. Pyridostigmine, the acetylchol inesterase inhibitor, releases GH by this mechanism. Pyridostigmine/GH responses have been reported as enhanced in depression. The aim of th e current study was to examine such responses during a manic episode. DESIGN A between subjects design was employed. SUBJECTS Seven male man ic patients and seven male healthy controls were studied. They were ma tched in terms of age and body mass index. MEASUREMENTS GH response to pyridostigmine (120 mg) challenge was measured as the net increase ab ove baseline. Cortisol levels were also measured. RESULTS Release of o n in the manic patients was significantly enhanced and their baseline cortisol levels were elevated. CONCLUSIONS These results demonstrate e nhanced pyridostigmine/GH responsiveness in mania which may be due to enhanced somatostin tone or increased cholinergic receptor responsivit y.