Vasodilative Effect And Mechanism Of Gingerol On Isolated Thoracic Aorta Ring Of Rabbits

BackgroundGingerol is the major ingredient of spicy in the ginger, with the medical functions of hypotensive, antioxidation and antitumor. Through research, different dosages of gingerol has different effect on vessels.Suekawa|3|found out that Low dosages of gingerol has the effect of hypotensive while high dosages will have three stages of reaction, that is, blood pressure drops dramatically, then rise, and finally fall gradually. Materials which can expand vessels secreted by vascular endothelial cells, mainly including NO and PGI2and so on, activate guanyly cyclase in vascular smooth muscle cells, making cGMP concentration in cells going up and lowering dissociative calcium ion concentration intracytoplasm, further leading to vasodilation when PGI2exerts the function of expanding vessels after its specificity receptor binding. Its function to expand vessels has been observed via many experiments, but its mechanism is not clear.ObjectivesAdopting the studying method of the isolated vessel of rabbits, and measuring the changes of vessel tension, we observe the effect of gingerol on the pre-contraction induced by NE or KC1in the isolated thoracic aorta rings with intact endothelium of rabbits, and the effect on endothelium-intact or endothelium-denuded thoracic aorta contraction induced by NE or KC1, and further probe whether it has relation with endothelial cells, calcium channel, NO and PGI2, so as to illustrate gingerol effect on thoracic aorta smooth muscle and its potential mechanism.MethodsThe thoracic aortic ring muscle strips with intact and denuded endothelium were prepared and placed in a15mL organ chamber containing physiological salt solution (PSS). Every strip was connected to the tension transducer and the change of the vascular ring tension was recorded and analyzed by the biological signal collection and analysis computer system. The PSS was bubbled with95%O2and5%CO2and an optimal basal tension was adjusted to2.5g. Observe the effect of gingerol on the pre-contraction induced by norepinephrine (NE,10-5mol/L) or KC1(20mmol/L) in the isolated thoracic aorta rings with intact endothelium of rabbits, and the effect of gingerol on the pre-contraction induced by norepinephrine (NE,10-5mol/L) or KC1(20mmol/L) in rabbit isolated thoracic aortic rings with endothelium-intact or endothelium-denuded. Meanwhile, we also observed the effect of N-nitro-L-arginine methyl ester (L-NAME,10-4mol/L) and indomethacin (10-8mol/L) on the action of gingerol in the rings.Results(1)The thoracic aortic rings with intact endothelium could produce the contraction effect after administratingl0-5mol/L NE or20mmol/L KC1, and then appear the relaxation effect after adding the different concentration of gingerol in organ chamber. The diastolic function of muscle strips was bigger and bigger with the increasing concentration of gingerol, which had a dose-dependent.(2)The thoracic aortic rings with intact and denuded endothelium could produce the contraction effect after administratingl0-5mol/L NE or20mmol/L KC1, and then appear the relaxation effect after adding the different concentration of gingerol in organ chamber, especially in the thoracic aortic rings with intact endothelium. The diastolic function of muscle strips was bigger and bigger with the increasing concentration of gingerol, which had a dose-dependent.(3)The thoracic aortic rings with intact and denuded endothelium could produce the contraction effect after administrating L-NAME, and then appear the relaxation effect after adding the different concentration of gingerol in organ chamber, especially in the thoracic aortic rings with intact endothelium. The diastolic function of muscle strips was bigger and bigger with the increasing concentration of gingerol, which had a dose-dependent. While without L-NAME, the contraction effect of the thoracic aortic rings dropped dramatically.(4)The thoracic aortic rings with intact and denuded endothelium could produce the contraction effect after administrating indomethacin, and then appear the relaxation effect after adding the different concentration of gingerol in organ chamber, especially in the thoracic aortic rings with intact endothelium. The diastolic function of muscle strips was bigger and bigger with the increasing concentration of gingerol, which had a dose-dependent. While without indomethacin, the contraction effect of the thoracic aortic rings dropped dramatically.ConclusionGingerol has an inhibition effect on contraction reduced by NE or KC1, which has a dose-dependent, its mechanism may be related to NO generated by endothelium and PGI2.