Effects of Angiotension I-Converting Enzyme Activity on the Aorta Adventitial Remodeling

Objective To investigate the relationship between adventitia activation and collagen metablosim in rat via the observation of the changes of the adventitial angiotension I-converting enzyme(ACE)activity in the spontancous hypertensive rats(SHR)and Wistar rats,and the possible mechanism of blood vessel remodeling and functional regulation of adventitia.Methods Ten 20 weeks old male spontancous hypertensive rats were used for the experiment group and ten 20 week old male Wistar rat were used for the control group.Blood pressure and heart beat of the rats were measured by tail-cuff method every week.Pathomorphology of the main artery was studied and blood vessel collagen content and ACE activity were determined by spectrophotometer.Results ACE activity of the adventitia of the SHR was significantly higher than that of Wistar rats,and the adventitialy ACE activity was correlated with adventitial collagen level(r=0.65).Conclusion The adventitia of the spontenous hypertensive rat was activated;ACE activity was increased and related to the increase of adventitial collagen.The activation of adventitia in the hypertensive blood vessel remodeling is important.