Role of spinal adenosine A1 receptors in the analgesic effect of electroacupuncture in a rat model of neuropathic pain.

OBJECTIVE: The aim of this study was to determine the role of spinal adenosine A1 receptors (A1Rs) in the analgesic effects of electroacupuncture (EA) for neuropathic pain. METHODS: We performed EA for 30 minutes at the zusanli acupoint in the legs of rats with previously induced chronic constriction injuries and observed the mechanical and thermal pain thresholds 1 hour later. We also examined adenosine levels by high-performance liquid chromatography and A1R expression in the L4-6 spinal cord by western blot analysis. We then injected A1R short interfering RNA (AV-shA1RNA) into the L4-6 spinal cord to downregulate A1R expression and re-examined the mechanical and thermal pain thresholds. RESULTS: Adenosine levels and A1R expression in the L4-6 spinal cord were increased at 1 hour after EA. In addition, EA exhibited an analgesic effect that was reversed by AV-shA1RNA. CONCLUSIONS: Our results suggest that EA at the zusanli acupoint elicits an analgesic effect against neuropathic pain, mediated by A1Rs in the spinal cord.

Electroacupuncture-induced neuroprotection against focal cerebral ischemia in the rat is mediated by adenosine A1 receptors.

The activation of adenosine A1 receptors is important for protecting against ischemic brain injury and pretreatment with electroacupuncture has been shown to mitigate ischemic brain insult. The aim of this study was to test whether the adenosine A1 receptor mediates electroacupuncture pretreatment-induced neuroprotection against ischemic brain injury. We first performed 30 minutes of electroacupuncture pretreatment at the Baihui acupoint (GV20), delivered with a current of 1 mA, a frequency of 2/15 Hz, and a depth of 1 mm. High-performance liquid chromatography found that adenosine triphosphate and adenosine levels peaked in the cerebral cortex at 15 minutes and 120 minutes after electroacupuncture pretreatment, respectively. We further examined the effect of 15 or 120 minutes electroacupuncture treatment on ischemic brain injury in a rat middle cerebral artery-occlusion model. We found that at 24 hours reperfusion,120 minutes after electroacupuncture pretreatment, but not for 15 minutes, significantly reduced behavioral deficits and infarct volumes. Last, we demonstrated that the protective effect gained by 120 minutes after electroacupuncture treatment before ischemic injury was abolished by pretreatment with the A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (1 mg/kg, intraperitoneally). Our results suggest that pretreatment with electroacupuncture at the Baihui acupoint elicits protection against transient cerebral ischemia via action at adenosine A1 receptors.

[Effects of nimodipine on rabbits with symptomatic cerebral vasospasm].

OBJECTIVE: To investigate the effects of nimodipine on symptomatic cerebral vasospasm in rabbits. METHODS: Twenty four japanese white rabbits which ligation of bilateral common carotid arteries and no neurological deficits were randomized to sham-operation, subarachnoid hemorrhage (SAH) and nimodipine which injected of nimodipine 0.1 mg/kg, continuous vein administration 5 day. The behavior scores, neurological scores were observed everyday and cerebral angiography changes were measured twice by 3D-CTA, and basilar artery was removed for pathological examination after last CTA examination. RESULTS: In SAH group, The basilar artery were significantly vasoconstrictive on 5 days, neurological scores were increased, and the basilar artery was found apoptosis-like changes under light microscopic and electron microscope. Nimodipine group could not dilated the basilar artery arteriospasm after SAH, but it could attenuate neurological deficit, and obviously alleviate the pathological changes of basilar artery. CONCLUSION: Nimodipine could not vasodilation of basilar artery in SCVS, but obviously could alleviate neurological changes and pathological changes of basilar artery in rabbits with symptomatic cerebral vasospasm.

[Preventive effect of transcutaneous electro-acupuncture on the intratracheal extubation stress response in general anesthesia of patients with breast cancer undergoing modified radical mastectomy].

OBJECTIVE: To observe the regulatory effect of transcutaneous electro-acupuncture (TCEA) for preventing intratracheal extubation stress response (IESR) in general anesthesia. METHODS: Sixty patients with breast cancer scheduled to receive mastectomy were numbered according to their sequence of hospitalization, patients of odd number were assigned to the control group and those of even number to the treated group, 30 in each group. They were anesthetized by the same anesthesia approach, but TCEA was applied on patients in the treated group in the narcotic process by stimulating at Hegu (LI4) and Neiguan (PC6) of the diseased side for 20 min before induction; then on bilateral points of Hegu, Neiguan, Chize (LU5) and Lieque (LU7) all through the whole course of operation, but at time of 30 min before ending operation, stimulus at Chize and Lieque points stopped and turned to bilateral Shuitu (ST10) and Qishe (ST11) points. No management other than conventional anesthesia was applied on patients in the control group. Changes of blood pressure (MAP), heart rate (HR), plasma catecholamine and cortisol as well as the respiratory tract response occurred after extubation were observed and compared. RESULTS: HR, MAP, plasma levels of catecholamine and cortisol increased after extubation in both groups (P < 0.05), but the changes were more obvious in the control group than in the treated group (P < 0.05). Besides, the adverse reaction of respiratory tract occurred in the treated group was milder (P < 0.05). CONCLUSIONS: TCEA can alleviate the IESR to attenuate the adverse reaction of respiratory tract. It is definitely valuable in clinical practice.