DENERVATION, BUT NOT DECENTRALIZATION, REDUCES NERVE GROWTH-FACTOR CONTENT OF THE MESENTERIC-ARTERY

In the present study we applied an improved nerve growth factor (NGF) extraction method to examine the effects of denervation and sympatheti c decentralization on NGF levels in vascular tissue. Adult male Wistar Kyoto rats underwent mesenteric arterial denervation or splanchnic ne rve transection. Four days after operation, animals were killed, and t he mesenteric artery and coeliac-superior mesenteric ganglia were remo ved. The arterial adventitia was stripped from the media to measure NG F levels in nerve and smooth muscle separately. A high concentration o f NGF was detected in the normal artery, 90% of which was in the adven titial layer. Surgical denervation significantly reduced the NGF level s in the artery and ganglia by 78 and 71%, respectively. However, with in the artery the level of NGF was reduced in the adventitia but not i n the media. Thus, the large reduction of NGF content resulted from th e loss of nerve plexus from the artery, In contrast, decentralization did not alter the NGF content in the artery, in either the adventitia or media. Our results are in marked contrast to previous studies repor ting elevated levels of NGF following denervation. This discrepancy is explained by the ability of our new procedure to extract much greater amounts of NGF from the tissue.