Disappearance of catecholamine fluorescence from the adrenergic nerves in arterial grafts in rats: an experimental fluorescence histochemical study.

The disappearance of catecholamine fluorescence from the noradrenaline-containing sympathetic nerve fibres after arterial transplantation was studied using a femoral artery graft sutured to rat carotid artery. Glyoxylic acid-induced fluorescence was used to demonstrate adrenergic nerves histochemically. At six hours the network of fibres had started to degenerate, and catecholamine fluorescence from the adrenergic nerves had almost completely disappeared within 24 hours of grafting. Control specimens from normal femoral arteries showed a dense network of fluorescent adrenergic nerves. Based on observations of the relatively rapid liberation of catecholamines from the degenerating adrenergic nerves, we suggest that catecholamines liberated from degenerating adrenergic nerves may have an important role in early vasospasm in microvascular and coronary bypass surgery.