| Objective:Guided by the thought of "preventing disease" in traditional Chinese medicine,this study discusses the preventive protective effect of acupuncture at Renying point on blood pressure and blood vessels in spontaneously hypertensive rats(SHR),and based on TGF-β1/ Smad signaling pathway to explore the possible mechanism of acupuncture antihypertensive and vascular protection,in order to provide some experimental basis and new ideas for acupuncture prevention and treatment of hypertension.Methods:In this experiment,20 male SHRs(4-week-old)were selected as the research object,and 10 Wistar rats of the same age were selected as the normal control group.Rats in each group were adaptively fed for 1 week,fed freely,and then adaptively bound with self-made rat clothes for1 week.Before acupuncture treatment,the blood pressure and body weight of rats in each group were measured and recorded,and 20 SHRs were randomly divided into model group and acupuncture group,with 10 rats in each group.During the acupuncture experiment,take the two sides of Renying points of rats,twist the manipulation for 1 min with the frequency of 2times/second,keep the needle for 15 min,continuously acupuncture for 5 days a week,rest for2 days,a total of 22 weeks.The normal group and the model group were given the same binding time as the acupuncture group.The blood pressure of rats in each group was measured by noninvasive sphygmomanometer,and the morphology of thoracic aorta was observed by HE and Masson staining,collagen volume fraction(CVF)was also calculated.RT-q PCR was used to detect the m RNA expression of TGF-β1,Smad3 and Smad7 in thoracic aorta.Western blot was used to detect the protein expression of TGF-β1,Smad3,Smad7 and type I collagen(Col I)in thoracic aorta respectively.Results:1 Blood pressure of rats in each group(1)Intra group comparison showed that blood pressure of the normal group at each measurement time point changed little compared with that before acupuncture,and there was no significant difference(P>0.05);The blood pressure at each measuring time point in the model group was significantly higher than that before acupuncture(P<0.05);The systolic blood pressure in the acupuncture group was significantly different from that before acupuncture at week 4,week 6,week 18,week 20 and week 22(P<0.05),and the diastolic blood pressure was significantly different from that before acupuncture at week 4,week 18 and week 22(P<0.05),and there was no significant difference at other time points(P>0.05).(2)Comparison between groups showed that before acupuncture treatment,there was no significant difference in blood pressure between the model group and the acupuncture group(P>0.05),but they were significantly higher than those in the normal group(P<0.05);After acupuncture treatment,the systolic blood pressure of the acupuncture group was significantly different from that of the model group from the second week to the end of the experiment(P<0.05),and the diastolic blood pressure was significantly different from that of the model group from the sixth week to the end of the experiment(P<0.05).2 Comparative observation on the morphology of thoracic aorta of rats in each groupHE staining results showed that in the normal group,the morphology of thoracic aorta was normal,the intima of blood vessel was smooth,there was no shedding of endothelial cells,the thickness of media was moderate,there was no obvious proliferation of smooth muscle cells,and the blood vessel wall was not thickened;Compared with the normal group,the intimal injury of thoracic aorta in the model group was obvious,with endothelial cells falling off,media thickening,smooth muscle cell proliferation,increased nuclear density and thickening of vascular wall,showing obvious vascular remodeling;Acupuncture can improve the surface condition of vascular intima,reduce the abscission of endothelial cells and the proliferation of medial smooth muscle cells,and reduce the thickness of vascular wall.3 Collagen deposition in thoracic aorta of rats in each group and its resultsMasson staining results showed that in the normal group,the morphology of thoracic aorta was normal,and the collagen fibers between smooth muscle bundles were evenly distributed,neatly arranged and less content;In the model group,the wall of thoracic aorta was significantly thickened,a large number of collagen fibers were deposited,and CVF was significantly higher than that in the normal group(P<0.05);Compared with the model group,the above situation in the acupuncture group was improved,the deposition of collagen fibers was reduced,and CVF was significantly reduced(P<0.05).4 Expression of COL I protein in thoracic aorta of rats in each groupWestern Blot results showed that the expression of COL I protein in thoracic aorta of model group was significantly higher than that of normal group(P<0.05);Compared with the model group,the expression of COL I protein in the acupuncture group decreased significantly(P>0.05).5 Related m RNA and protein expression in TGF-β1/Smad signaling pathwayRT-q PCR results showed that compared with the normal group,the expression of TGF-β1and Smad3 m RNA increased significantly in the thoracic aorta of SHRs in the model group(P<0.05),and the expression of Smad7 m RNA decreased significantly(P<0.05);After acupuncture treatment,compared with the model group,the m RNA expression of TGF-β1decreased significantly in the thoracic aorta of SHRs in the acupuncture group(P<0.05).Although there was no significant difference in the expression of Smad3 and Smad7 m RNA(P>0.05),the expression of Smad3 m RNA had a downward trend and Smad7 m RNA had an upward trend.Western Blot results showed that compared with the normal group,the expression of Smad3 protein in the thoracic aorta of SHRs in the model group increased significantly(P<0.05),the expression of Smad7 protein decreased significantly(P<0.05).Although there was no significant difference in TGF-β1 protein expression(P>0.05),there was an upward trend.After acupuncture treatment,compared with the model group,although there was no significant difference in the expression of TGF-β1、Smad3 and Smad7 proteins(P>0.05),it can be seen that the expression of TGF-β1 and Smad3 protein had a downward trend and Smad7 protein had an upward trend.Conclusions:1 Early acupuncture at Renying point can reduce the blood pressure of SHRs,alleviate the continuous increase of blood pressure,improve vascular remodeling,and then delay the process of vascular remodeling.2 Acupuncture at Renying point may regulate TGF-β1/Smad signal transduction pathway to protect blood vessels.The mechanism may be through decreasing the expression of TGF-β1and Smad3 and increasing the expression of Smad7 in the thoracic aorta of SHRs,thereby inhibiting TGF-β1/Smad signal transduction can improve vascular remodeling and protect blood vessels in hypertension. |
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