DEFICIENT VASCULAR INNERVATION IN FAMILIAL DYSAUTONOMIA, AN EXPLANATION FOR VASOMOTOR INSTABILITY

Abstract

Deficient vascular innervation in familial dysautonomia, an explanation for vasomotor instability An ultrastructural study of peripheral blood vessels in familial dysautonomia demonstrates the absence of autonomic nerve terminals. In control subjects both sympathetic terminals containing dense‐cored vesicles and presumptive cholinergic terminals containing agranular vesicles are readily shown. Lack of autonomic innervation of blood vessels in familial dysautonomia accounts for postural hypotension and other abnormalities of vasomotor reflexes. It also explains exaggerated responses to sympathomimetic and parasympathomimetic agents in terms of denervation hypersensitivity. Ultrastructural analysis of vascular nerve terminals may be of general value in the study of many diseases which show vasomotor instability.