Meicha Extract On Rat Vascular Function Effects And Mechanism

Object:The study of different solvents extract of the meicha on isolated vascular rings gets the active vascular site.The use of normal rat thoracic aortic rings and essential hypertension?SHR?rats,using molecular biology techniques research meicha tea extract on vascular structure and function,and to explore its mechanism of action.In order for Meicha rational development and utilization of resources provide theoretical and experimental evidence.Method:1.Meicha extract on isolated vascular rings active site screeningFor the first time,the Meicha extracts of different solvents vascular rings in vitro experiment research,observe Meicha ethanol extract parts of methanol,ethyl acetate extract,acetone parts,petroleum ether and chloroform part of noradrenaline?NA?due to reduced vascular response.2.The role of Meicha flavonoids on isolated vascular ringsTo research the in vitro effect of total flavonoids of meicha dihydrom-yricetin and myricetin on thoracic aorta rings of rats,a biological signal col-lection and analytical system was applied to observe the tension of resting thoracic aorta rings and the dose-effect curve of the contractile response induced by noradrenaline?NA?.3.Impact on total flavonoids Meicha Spontaneously Hypertensive Rats?SHR?thoracic aortic diastolic function and remodelingThe SHR were randomly divided into model group,total flavonoids low dose group?90mg·kg-1?,total flavonoids dose group?180mg·kg-1?,total flavonoids high-dose group?360mg·kg-1?and compound Apocynum piece group?50mg·kg-1?.Last noninvasive arterial blood pressure changes observed manometry,HE staining morphology index measuring the thoracic aorta,vascular tone in vitro assay to detect reactive thoracic aortic diastolic function,nitrate reductase assay levels of NO,Real-Time PCR Determination of the thoracic aorta eNOS,ACE,?C-myc Bcl-2,P27 mRNAResults:1.The The Ethyl acetate extractio site ofMeicha a shifted the dose-effect curve of the contractile response induced by NA to the right and decreased their maximal efficiency(E_max).2.The results showed that meicha flavonoids,dihydromyricetin and myricetin can increase the tension of resting thoracic aorta rings in a dose-dependent manner.The total flavonoids of meicha shifted the dose-effect curve of the contractile response induced by NA to the right and decreased their maximal efficiency(E_max).The similar effects were also observed in dihydromyricetin and the mixture of dihydromyricetin and myricetin,wherein the mixture lowered much more E_maxax than either of the two isolets applied individually.In particular,the mixture comprising of dihydromyricetin and myricetin with concentration ratio of 10:1 showed better effect.3 Meicha total flavonoids can inhibit blood pressure in SHR rats with the natural course of the rise,medium and high doses of flavonoids can significantly reduce blood vessel thickness,and high doses of flavonoids can significantly reduce the thickness of the blood vessel lumen diameter ratio;in vitro vascular ring functional assay experiments,total flavonoids Meicha dose-dependent improvement in SHR rat thoracic aorta to Ach-induced vasodilation response,there was no significant difference in vasodilatory effects of SNP-induced reactions;high dose flavonoids can organizations can significantly increase eNOS mRNA,increased serum NO content;Meicha total flavonoids could cut each dose vascular tissue ACE,Ang?,C-myc,Bcl-2 mRNA also raised P27 mRNA.Conclusion:1 The Ethyl acetate extract elution site of Meicha has a strong vascular regulation,can inhibit the vasoconstrictor response NA,effective active site for ring vitro blood vessels.2.The flavonoids of meicha induced dose-dependent contraction in isolated thoracic aorta rings in rats and can significantly noncompetitively antagonize NA induced contraction of rat aortic rings,and dihydromyricetin and myricetin synergistically antagonize NA induced contraction of vascular rings with optimum ratio of 10:1.3.SHR animal experiments showed Meicha flavonoids can relieve the symptoms of high blood pressure,improve vasodilation in blood pressure overload-induced disorders and prevention of hypertension vascular remodeling.Improve vasodilation and increase thoracic aortic eNOS gene expression levels related to increased NO synthesis.Blood pressure overload caused by inhibition of vascular remodeling and regulation of the RAS system-related genes and VSMC proliferation-related genes.