AXONAL-TRANSPORT OF NITRIC-OXIDE SYNTHASE IN AUTONOMIC NERVES

By using mechanical nerve ligation or nerve pinch technique, we provid e evidence that nitric oxide synthase (NOS) is transported in the preg anglionic sympathetic axons, while postganglionic axons lack NOS trans port. This finding corroborates the preganglionic sympathetic terminal as the site of NO synthesis, which is known to affect ganglionic tran smission. Both vasoactive intestinal polypeptide (VIP) and substance P (SP) containing neurons of the nodose ganglion transport NOS in their axons. These results therefore suggest that NOergic innervation of au tonomically innervated tissues is of parasympathetic and/or sensory, r ather than sympathetic, origin.