Brain Particles In Yangyintongnao Canine Cerebral Blood Flow And Its Mechanism

Background and objectiveCerebral ischemia is a common disease of old people. With the increasing aging of our country, the more and more attenlion is paid to the prevention and therapy of the cerebral ischemic disease by doctors. Rich experiences were accumulated in traditional Chinese medical practice. Many Chinese medicine had been proved to be effective in long-term use. Therefore, traditional Chinese medicine and herbs may hare favourable application prospect in cerebralvascular disease.Yangyintongnao particle is composed of several traditional Chinese medicine including shengdk shiluu chuanxiong^ hirudo> gegen and Radix Astragali seu Hedysari. The chief purpose of the present study was to assess the role of yangyintongnao particle on cerebral blood flow, cerebrovascular resistance, cardiac performance, mean blood pressure and heart rate in anaesthetized dog.METHODS:1. 29 dogs were randomly allocated to five groups. In control group physiological solution was administered with gastrogavage, In other four groups, a large dose of yangyintongnao particle(2g/kg),a middle dose of yangyintongnao particle(lg/kg), a small dose of yangyintongnao particle(0.5g/kg)and weinaolutong pian were administered with gastrogavage respectively.2. Blood flow of carotid artery internal was detected by electricmagneticflowmeter. Aortic mean blood pressure via a piezometric transducer was measured by femoral artery intubation, cerebrovascular resistance was calculated. A heart sound transducer was placed on the precordium. A standard II lead of ECG was used to record. ECG, Phonocardiogram (PCG), flow rate and blood pressure were simultaneously recorded on 4-channel polygraphy.3. Systolic time intervals(STIs) were measured from the simultaneous recording of the blood pressure wave, phonocardiogram and eletrocardiogram. The index of STIs are Q-S2(electromechamical systole). LVET(left vertricular ejection time), PEP(pre-ejection period) and PEP/LVET ratio. Q-S2 is measured from the beginning of Q wave of ECG to the initial point of aortic valve in the 2nd heart sound. LVET is measured from blood pressure wave, it is the duration from the initial point of systolic wave to the notch on the dicrotic wave. PEP is calculated from Q-S2 minus LVET.4. mean blood pressure was measured, heart rate was obtained from R-R intervals of electrocardiogram.RESUTS:1. A middle dose of yangyintongnao particle was remarkable in increasing cerveral blood flow following administion 30,60,90min, a middle dose and a large dose of yangyintongnao particle increase cerebral blood flow more than weinaolutong in 30 min, Yangyintongnao particle can increase cerebral blood flow in campare to weinaolutong.2. Yangyintongnao particle can decreased cerebrovascular resistance, a Middle dose of yangyintongnao particle reduce resistance of dog cerebrovessel 1 more than a large dosage.3. Yanyintongnao particle and weinaolutong reduce PEP/LVET ratio,prolong LVET and shorten PEP.4. yangyintongnao particle reduced slightly mean blood pressure and heart rate, weinaolutong raised lightly blood pressure and slow heart rate, their effect were slight, the charges of heart rate and mean blood pressure had no significant.CONCLUSION:1 .Yangyintongnao particle cause cerebral vasodilation, it resulted in reduction of cerebrovascular resistance and increase of cerebral blood flow, it was obviously superior to the small dosage of weinaolutongpian. Results suggested that yangyintongnao particle possess protective effect against cerebral ischemia.2. Yangyintongnao particle and weinaolutong are able to improve cardiac performance, their effect may be related to increase cerebral blood flow.