Effects Of Ear Acupuncture Of "Thoracopneumatic Area" On Hypertension Rabbits

Objective: To investigate the mechanism of ear acupuncture by studying the effects of acupuncture of "thoracopneumatic area" (TPA) on acute breadboard hypertension rabbits . Methods:40 healthy rabbits were divided randomly into five groups: model control group, PGL microinjection NS group(NS group) , PGL microinjection NS and acupuncture of TPA group(NS+ZC group), PGL microinjection Naloxone group(NAL group), PGL microinjection NAL and acupuncture of TPA group(NAL+ZC group). The mean arterial pressure(mAP), heart rate(HR) , left intraventricular pressure(mLVSP) and maximum rate of intraventricular pressure change(LV+dp/dt max) were recorded. When the injection of Norepinephrine (NE ) into femoral vein induced acute breadboard hypertension, the effects and mechanisms of acupuncture of TPA on acute breadboard hypertension rabbits were observed. Results: (1) When the injection of Norepinephrine (NE ) into femoral vein induced stable acute breadboard hypertension, mAP, mLVSP, LV+dp/dt max increased significantly, HR decreased slightly, this state can last more than two hours. (2)When NS , NAL was microinjected respectively into PGL, there's no significant change on hypertension rabbits, mAP, mLVSP, LV+dp/dt max and HR were not changed significantly.(3) When NS was microinjected into PGL with the acupuncture of TPA simultaneously could make the blood pressure of hypertension rabbits decrease, mAP, mLVSP, LV+dp/dt max decreased significantly, HR decreased slightly.while NAL was microinjected into PGL, it could counteract the function of acupuncture,the extent of the variabilities of mAP, mLVSP,LV+dp/dt max and HR were reduced. Conclusion (1) Acupuncture of "thoracopneumatic area" can make the blood pressure decrease on hypertension rabbits induced by injection Norepinephrine (NE ) into femoral vein.(2) And this may partially rely on the releasing or activaction of Endogenous Opioid Peptide ( Eop) in rostral venteral lateral medulla cardiovascular center including PGL in medulla.