缰核内注射Ca^(2+)拮抗电针镇痛的作用可被三碘季铵酚翻转

ANTAGONISTIC EFFECT OF ELECTRO-ACUPUNCTURE ANALGESIA WITH Ca^(2+) INJECTION INTO HABENULA COULD BE REVERSED BY GALLAMINE TRIETHIODIDE

通过埋植套管向大鼠双侧缰核分别注射0.1mol/L CaCl_2 0.5μl,0.06mol/L ACh0.5μl,5.4×10^(-3)mol/L三碘季铵酚0.5μl和14.4×10^(-3)mol/L阿托品0.5μl后观察到,Ca^(2+)降低基础痛阈并拮抗电针镇痛效应;ACh拮抗电针镇痛;Ca^(2+)拮抗电针镇痛的作用可被胆碱能N受体阻断剂三碘季铵酚完全翻转。提示缰核内的Ca^(2+)可能通过ACh实现其拮抗电针镇痛的效应。

0.1 mol/L CaCl_2 0.5 μl, 0.06 mol/L ACh 0.5 μl, 5.4×10^(-3) mol/L gal-lamine triethiodide (cholinergic nicotinic receptor blocker) 0.5 μl and 14.4×10^(-3)mol/L atropine (cholinergic muscarinic receptor blocker) 0.5 μl were injectedthrough bilateral intracranial cannulae in rat habenula. Pain threshold wasmeasured by the latency of tail-flick reflex elicited by radiant heat exposure beforeand after intracerebral injection. CaCl_2 significantly reduced the basic painthreshold and weakened the effect of the acupuncture analgesia. ACh apparentlyantagonized the effect of acupuncture analgesia. Gallamine triethiodide couldrecover the pain threshold almost to the raised level by acupuncture, butatropine only strengthened the effect on pain threshold weakly and briefly.The results suggest that the antagonistic effect of Ca^(2+) may be mediated via AChin habenula.