[Relationship between nitric oxide synthase, endothelin and the initiation of hypertension and atherosclerosis]

To investigate the relationship between nitric oxide synthase (NOS), endothelin (ET) and the initiation of hypertension and atherosclerosis, 5 hypertensive rats (systemic pressure 22.7-24 kPa), 5 atherosclerotic rats (by cholesterol-rich diet, 3 months), and 5 normal Wistar rats were used for determination of the distribution of NOS and ET of aorta by histochemical methods. The levels determined in the three groups were quantitated and compared by computer-imaging analysis. The results showed that in early stage of atherosclerotic process, the NOS decreased while the ET increased in aorta. In early stage of essential hypertension, however, both NOS and ET levels increased. These results suggest that the increased ET and the change of NOS may play a role in the pathogenesis of hypertension and atherosclerosis.