Noradrenergic nerve fibers of the rectal mucosa in autonomic disorders: comparison of histochemical study with clinical severity and changes in plasma noradrenaline induced by standing

Abstract

A histochemical study was carried out on the rectal mucosae biopsied from 20 patients with autonomic dysfunctions and 13 controls using a catecholamine fluorescent staining method, and the rectal noradrenergic nerve fiber lesions were compared with the severity of autonomic symptoms and disturbance of plasma noradrenaline increase in response to standing in 17 patients. In 9 patients with type I familial amyloid polyneuropathy and 1 with acute pandysautonomia, the number of fluorescent nerve fibers was greatly reduced, and the degree of depletion correlated well with the other 2 parameters showing the severity of autonomic dysfunction. In contrast, rectal noradrenergic nerve fibers were normally preserved in 10 patients with multiple system atrophy, although they suffered from severe autonomic symptoms with poor noradrenaline response to the postural loading. It is concluded that noradrenergic nerve fiber lesions in the biopsied rectal mucosa may represent the systemic involvement of sympathetic post-ganglionic nerves.