Abstract: AIM: To explore the effect of atorvastatin on the function of carotid artery after adventitia removal in SHR. METHODS: 16-week old male SHR (n=36) with left carotid artery adventitia removed were randomly divided into 3 groups (n=12, each):SHR control group, atorvastatin group, valsartan group and the half rats of each group were put to death at the 4th and 8th weeks respectively.The systolic blood pressure (SBP) was assessed before and after treatment with atorvastatin every 2 weeks.The velocity of carotid artery was detected by electromagnetic rheometer while vasotension changes to NE was measured using a force transducer connected with a polygraph. RESULTS: Compared with SHR control group, the SBP of atorvastatin group began declining at the 4th week, and was reduced significantly at the 6th and 8th weeks (P<0.05, P<0.01).The resistance index of carotid artery was reduced significantly in atorvstatin group and valsartan group than that in SHR control group (P<0.05, P<0.01), and it was, at the 4th week, lowered slightly in adventitia removal side than that in normal control side while it was mildly higher at the 8th week, but there was no significant difference between the two sides(P>0.05).Vasotension to NE of carotid artery was reduced significantly after adventitia removal (P<0.01), it was improved by atorvastatin at the 4th week (P<0.01), but decreased mildly at the 8th week(P<0.05). CONCLUSION: Atorvastatin causes a significant reduction of blood pressure in SHR.Adventitia removal makes the vascular resistance of SHR slightly lower at the early stage but higher later, treatment with atorvastatin may lead to decreasement of vascular resistance including the side without adventitia removal.Adventitia removal depresses the vasotension to NE in SHR, the depressed vasotension to NE after adventitia removal can be improved by atorvastatin at the early stage while it can be worsen later.

Key words: atorvastatin, spontaneously hypertensive rats, carotid artery, adventitia, vascular remodeling, vascular resistance