Neuropeptide Processing Enzymes of the Carotid Body

Abstract

Several studies using immunocytochemical approaches have demonstrated that a variety of neuropeptides occur in the carotid body and that they are associated with nerve fibers or type I cells or blood vessels (Table 1). Furthermore, elegant electrophysiological studies showed that carotid body activity is augmented by exogenous administration of neuropeptides like substance P (McQueen, 1980; Prabhakar et al, 1989) and endothelins (Chen et al, 1994) whereas it is attenuated by enkephalins (Monti-Bloch & Eyzaguirre, 1985), and atrial natriuretic peptide (Wang et al, 1991). The occurrence of multiple neuropeptides and their exogenous effects on the activity of the carotid body suggest that they may be of importance in the sensory response of the carotid body.