In 63 patients suffering from an obliterating thromboangiitis and atherosclerosis the state of the efferent innervation of the shin and foot vessels has been studied. The material has been obtained during reconstructive surgical operations from various segments of the extremities and in the patients suffering from regional ischemic disorders of various degree. Moreover, adrenergic structures of the lumbar sympathetic ganglia have been investigated after sympathectomy performed. In the patients suffering from thromboangiitis, in the adventitial arterial tunic some foci are revealed containing single adrenergic neural fibers. Topography concerning localization of these foci is extremely asystematic. At atherosclerosis the innervational structures have character of a chronic exhaustion. In the sympathetic ganglia neurons, catecholamine-containing structures are revealed; they are seen as accumulations of norepinephrine granules. As demonstrates the comparison of the clinical and neurohistochemical data, in development of the obliterating thromboangiitis a sharp catecholamine deficiency and a pervent effect of the disturbed innervational connections on the vascular tunics play an essential role. At atherosclerosis the mechanism of the chronic exhaustion of the neuromediators belongs evidently, to the phenomenon of the "postmediatory stage" of the neural elements ontogenesis.