The Role of Vascular Smooth Muscle Cells in Carotid Arteries Remodeling of Spontaneously Hypertensive Rats and the Intervention Study of Telmisartan

Abstract: To investigate the role of vascular smooth muscle cells (VSMCs) and the effects of telmisartan on carotid arteries remodeling in spontaneously hypertensive rats (SHR). 12 week-old-male SHRs were randomized to 3 groups (n=10 for each) ， including untreated SHR group， telmisartan high dose (TelH) group and telmisartan low dose (TelL) group. Age and sex matched Wistar Kyoto rats were served as control group (WKY). Systolic blood pressure (SBP) of rats， media thickness (MT)， medial cross-sectional area (MSCA)， mean nuclear area， VSMCs proliferating index (PI) and apoptosis index (AI) of carotid arterial were studied. The results showed that: ①The SBP level in TelH group was significantly decreased when compared to that in SHR group (P<0.01). Moreover， the lower SBP in TelH group was kept until to the end of experiment. However， there was not different between SHR group and TelL group (P>0.05). ②The MT， MCSA in SHR group were higher than those in WKY group respectively (P<0.01 for each). The MT， MCSA in TelH group were lower than those in SHR group respectively (P<0.01 for each). The MT was reduced in TelL group when compared with SHR group (P<0.05 ). ③The mean nuclear area of carotid arterial media of both TelH and TelL group was significantly lower than that in SHR group respectively (P<0.05 for each). ④PI was not obviously difference in each group (P>0.05). AI in SHR group was lower than that in WKY group (P<0.01). AI in TelH， TelL group was higher than that in SHR group respectively (P<0.01). PI/AI in SHR group was higher than that in WKY group (P<0.01). PI/AI in TelH， TelL group was lower than that in SHR group (P<0.01). ⑤AI in carotid arterial media was significantly negative correlated with medial cross-sectional area (MSCA) (r=?.871， P<0.01). To sum up both hypertrophia and proliferation-apoptosis ratio disequilibrium of VSMCs may play an important role in the pathogenesis of carotid arteries remodeling in SHR. Besides its antihypertension， Telmisartan could attenuate significantly the remodeling of carotid arteries in SHR through decreasing hypertrophia and increasing apoptosis of VSMCs to proliferation-apoptosis ratio of VSMCs in carotid arteries of SHR.

CSTR: 32200.14.cjcb.2008.02.0025