Effects Of Ginkgo Biloba Extract On Blood Circulation In Rabbits

Microcirculation is sensitive to be injured, microcirculation disturbance is which cannot be satisfied the requirement of oxygen, nutrition metabolism, and induced oxygen deficiency and insufficiency of blood so as to initiate the functional disturbance of organs until exhaustion. At the same time, that is important morbidity to many diseases. More over, continuously existing microcirculation disturbance aggravates the progress of diseases. Cerebral thrombosis, cerebral hemorrhage, hypertension, pneumocardial disease, cervical syndrome, tumour, diabetes and many other diseases are concerned with microcirculation disturbance. Ginkgo biloba leaves contain many mainly medical components which included flavonoid active compounds and terpenoids(ginkgolid and bilobalide). The pharmacological action of Gingko biloba extract mainly displayed in protecting myocardial, againsting platelet activating factor (PAF) and protecting cerebral vascular and so on. However, report about the effect of Ginkgo biloba extract on heart rate, blood pressure and electrocardia in rabbits was very limited. The purpose of this study was to explore how the Ginkgo biloba extract improve the microcirculation disturbance of mesentery induced by norepinephrine(NE) and effect blood pressure, heart rate, electrocardia in rabbit so as to find some medicines to protect microcirculation or improve functional disturbance of microcirculation. And provide theory and practice basic to Ginkgo biloba extract for further exploitation, utilization and medical care.This studies' objects were big ear rabbits, which were randomly divided into several groups. The surface of mesenteric vascular beds in rabbits were dripped by NE in order to induce microcirculatory disturbance. In order to reflect the effect of Ginkgo biloba extract on blood circulation in rabbits, we measured the diameter of vessels, blood flow velocity, volume of blood flow, blood pressure(mean blood pressure, systolic pressure and diastolic pressure), heart rate and electrocardia before and after iv. injection of EGB(drug group) or PS(control group) on 1, 5, 10, 20, 30 and 60 minute. At the same time, compared with the effect of Ginkgo biloba extract(EGB), Puerarin, Cyclocarya paliurus(Batal) iljinskaja and magnetized Ginkgo biloba extract.The results showed that: l) The effect on improving mesentery microcirculation disturbance in EGB-1 group was as well as in control group. After iv. injection of EGB for 1 minute, the diameter of arterioles and venules was dilated, blood flow velocity and volume was increased(P<0.05 or P<0.01), but later the each index was restored (P>0.05). It proved that Ginkgo biloba extract(0.5mg/kg) had no remarkable effect on improving mesentery microcirculation disturbance by norepinephrine(NE) in rabbits. 2) EGB-2 group were similar with control group after giving drugs, the action time was only lasted 10 minutes(P<0.05 or P<0.01). These results presented that Ginkgo biloba extract(1.0 mg/kg) also had no significant effect on improving mesentery microcirculation disturbance in rabbits. 3) After giving drugs, the diameter of arterioles and venules was dilated, blood flow velocity and volume was increased significantly and kept this speed in 60 minutes(P<0.05 or P<0.01). It was infered that Ginkgo biloba extract(2.0 mg/kg) had obvious effect on improving mesentery microcirculation disturbance in rabbits. 4) Within giving medicine for 60 minutes, the diameter of arterioles and venules, blood flow velocity and volume had no obviously changed in EGB-4 group(P>0.05). It cuted that Ginkgo biloba extract(5.0mg/kg) had no remarkable effect on improving mesentery microcirculation disturbance in rabbits. 5) The effect of improving mesentery microcirculation disturbance was more obvious in magnetized EGB-2 group than in unmagnetized EGB-2 group. The action time of magnetized EGB-2 group was longer than unmagnetized EGB-2 group for 20 minutes (P<0.05 or P<0.01), which hinted magnetized Ginkgo biloba extract could improve the effect. 6) Puerarin was able to dilate arterioles and venules and increase velocity and volume of blood flow obviously(P<0.05 or P<0.01). The action time had continued 20 minutes. It was infered that the effect of Puerarin was better than the same dose of Ginkgo biloba extract on improving mesentery microcirculation disturbance. 7) The effect was the most significant on improving mesentery microcirculation disturbance in Cyclocarya paliurus(Batal) iljinskaja group than in contol group(P<0.05 or P<0.01), and the action was maintained in 60 minutes. However, after giving drugs for half an hour the heart rate and blood pressure were remarkably depressed (P<0.05 or P<0.01), but the electrocardia was no significant difference(P>0.05), which indicated Cyclocarya paliurus(Batal) iljinskaja(1.0mg/kg) had important significance to improve mesentery microcirculation disturbance and decrease heart rate and blood pressure in rabbits.The conclusion: 1. Ginkgo biloba extract(2.0mg/kg) was able to improve microcirculation disturbance of mesentery induced by norepinephrine(NE) significantly in rabbits. But this disturbance had no significant effect on the high or low concentration. And Ginkgo biloba extract had no significant effect on blood pressure, heart rate and electrocardia in rabbits. 2. Magnetized Ginkgo biloba extract had remarkable effect on microcirculation disturbance of mesentery, compared with unmagnetized Ginkgo biloba extract, the action time of the former was longer than latter for 20 minutes. 3. The effect of Puerarin(1.0mg/kg) was similar with Ginkgo biloba extract, but the action time was prolonged to 10 minutes and its effect was remarkably superior to it. 4. Cyclocarya paliurus(Batal) iljinskaja had the most significant effect on improving microcirculation disturbance of mesentery and decreasing blood pressure and heart rate. But it had no effect on electrocardia in rabbits.