[Peptidergic sweating in multiple system atrophy and hereditary spinocerebellar ataxia with special reference to calcitonin gene-related peptide].

Calcitonin gene-related peptide (CGRP)-like immunoreactivity has been demonstrated to be present in nerve terminals around the sweat glands. We have previously demonstrated that CGRP modulates the cholinergic sweating activity. The present study was designed to evaluate the locally administrated CGRP on sweating of patients with multiple system atrophy (MSA) and hereditary spinocerebellar ataxia (HSCA) consisting of 10 males and 11 females. Among 9 HSCA, 3 was diagnosed as Machado-Joseph disease by clinical and DNA diagnostic assessment. CGRP and methacholine chloride (MCH) was dissolved in saline solution to specified concentration, and 0.1ml of which was injected intradermally at the center of a forearm test area. The sweat rate was recorded continuously by the capacitance hygrometry in a relatively cool environment in which the spontaneous sweating was absent. CGRP significantly increased the sweat rate when it was administrated with MCH on normal subjects. There was a clear dose-dependent relationship between the dose of CGRP and its enhancement. This enhancement was significantly reduced in patients with MSA as compared with controls. On the other hand, most of HSCA showed no remarkable impairment of CGRP enhancement. These results suggest that peptidergic sweating is extensively affected in patients with MSA but is not in patients with HSCA, which may be the consequence of peptidergic sweating dysfunction in MSA.