Effects Of Qindan Capsule On Expression Of Vascular Adventitial Ⅰ Collagen And Ⅲ Collagen On Old Spontaneous Hypertensive Rats

Aim1. Observe Qindan capsule on blood pressure in spontaneously hypertensive rats.2. Observe the Qindan capsule on vascular adventitiaⅠ,Ⅲcollagen expression, and to explore the reversal of hypertensive vascular adventitia remodeling mechanism.Methods1. Study:32 SHR rats of 40 weeks old were randomly divided into 4 groups, the model group (SHR group), Qindan high dosage group (SHR+QDH group), Qindan low dosage group (SHR+QDL group), the Losartan group (SHR+Los group), Besides, 16 Wistar—Kyoto (WKY) rats of the same weeks were taken as the normal control (WKY control group) and Qindan group (WKY+QD group). SHR+QDH group was treated with high dosage 750mg/(kg·d); SHR+QDL group was treated with low dosage 150mg/(kg·d); SHR+Los group was given losartan 30mg/(kg·d); WKY+QD group were treated with high dosage 750mg/(kg·d); WKY and SHR control group were given an equal dosage of saline, once a day, continuous administration for 12 weeks. Rats in each group after the last administration in the fasted 24h, can not help but water. All the rats were anesthetized with intraperitoneal injection of 10% chloral hydrate follow-up experiments. 2. Research:(1) Determination of rat tail artery systolic pressures.(2)Observed aortic adventitiaⅠ,Ⅲcollagen by immunohistochemistry.(3)Real-time quantitative PCR detection of thoracic aortic adventitiaⅠ,Ⅲcollagen.(4)Western blotting detection of expression of I collagen.Results1. Comparison of systolic blood pressure of ratsFig 1,after 4 weeks from the administration, Qindan high dosage, low dosage group, and losartan group compared with the model group blood pressure decreased, the difference was statistically significant (P<0.05). Between 6 weeks to 12 weeks of administration, the rat blood pressure decreased even more significant in the high dosage group than in the low dosage group, the difference was significant (P<0.05).2. Thoracic aorta by immunohistochemistry determination(Table 2, Fig 2, Fig 3)The results showed that the model group than in the control groupⅠ,Ⅲcollagen expression was significantly increased, the difference was statistically significant (P<0.05); Qindan low dosage group and losartan group were lower expression compared with the model group (P<0.05). Qindan control group and normal control groupⅠ,Ⅲcollagen expression was no significant difference (P>0.05), Qindan high dosage group compared with the low dosage group was statistically significant (P<0.05), but compared with the losartan group, the difference was not statistically significant (P>0.05).3. Aortic wallⅠ,Ⅲcollagen mRNA expression comparedUsing 2-ΔΔCt method, typeⅠ,Ⅲcollagen gene expression relative to the Ct is converted to changes in multiples of WKY control group, the target gene can be obtained directly relative to the reference gene quantification. As shown in Figure 6 and 7, respectivelyⅠ,Ⅲcollagen in the amplification curve and dissolution peaks, indicatingⅠ,Ⅲcollagen is a specific gene expression, no primer-dimers and nonspecific amplification. As shown (Fig 4):WKY control group and WKY+QD group was no significant difference (P>0.05), Differences between the SHR+QDH group and SHR+QDL group were statistically significant (P<0.05). There were significant differences between SHR groups and WKY groups in thoracic aorta adventitiaⅠ,Ⅲcollagen mRNA expression (P<0.05). SHR+QDH group, SHR+QDL group and SHR+Los group of rat thoracic aortic adventitiaⅠ,Ⅲcollagen expression compared with the WKY rats increased significantly, reduced compared with the SHR group, the differences were statistical significance (P<0.05).4. I collagen protein expression by Western blottingThe order in expression of collagenⅠfrom low to high:WKY control group, WKY+QD group, SHR+Los group, SHR+QDH group, SHR+QDL group, SHR group.Ⅰcollagen in 120KD molecular weight around, with reference to actin, a molecular weight of 43KD, can be seen followed the trend of increased protein expression. TypeⅠcollagen and actin by the ratio of statistical analysis were shown in Figure 5:WKY control group and WKY+QD have no significant difference (P>0.05), SHR+QDH group and SHR+QDL differences between the groups have statistical significance (P<0.05). SHR group compared with WKY group, the difference was statistically significant (P<0.05); SHR+QDH group, SHR+QDL group, SHR+Los group were compared with SHR group, the difference was statistically significant (P<0.05); SHR+QDH group and the SHR+Los group difference was not statistically significant (P>0.05).ConclusionQindan capsule on SHR rats had significant antihypertensive effects, and its step-down mechanism was possibly associated with reducing SHR ratsⅠ,Ⅲcollagen expression level, and also with the reversal of vascular adventitial remodeling, inhibition of membrane fibrosis, and reducingⅠ,Ⅲcollagen synthesis and deposition of the vascular adventitia.