足底注射吗啡可阻止谷氨酸和天然辣椒碱引起的动物对放射热的逃避行为

目的探讨足底注射吗啡对由谷氨酸和天然辣椒碱引起的动物对放射热的逃避行为的影响，从而了解阿片和谷氨酸受体在末梢神经痛觉传递中的相互作用。方法120只健康SD雄性大鼠随机分为12组，每组10只。在大鼠后肢左侧足底分别注射（正常对照组不用药）、生理盐水组（saline组）、谷氨酸组（Glu组）、天然辣椒碱组（Cap组）、吗啡组（Mor组）、盐酸纳洛酮组（NLX组）、谷氨酸牟吗啡组（Glu＋Mor组）、谷氨酸＋盐酸纳洛酮组（Glu＋NLX组）、谷氨酸＋盐酸纳洛酮＋吗啡组（Glu＋NLX＋Mor组）、天然辣椒碱＋吗啡组（Cap＋Mor组）、天然辣椒碱＋盐酸纳洛酮组（Cap＋NLX组）、天然辣椒碱＋盐酸纳洛酮＋吗啡组（Cap＋NLX＋Mor组）；注射药物15min，1、2、3、4、5、6h后分别观察SD雄性大鼠双足温度逃避域值的变化。结果大鼠双足逃避域值的变化，正常对照组左足的温度逃避域值为（11．7±0．29）s，右足的温度逃避域值为（11．5±0．4）s，两者的比为100％；saline组、Mor组、NLX组左右足的温度逃避域值比均为100％，3组比较差异无统计学意义（P〉0．05）；Cap组最大减少幅度发生在15～180min之间150nmol为（66．4±3．9）％；300nmol为（70±4．3）％]，与saline组比较差异有统计学意义（P〈0．05）；Glu组最大减少幅度发生在15～120min之间1．5μmol为（85．9±1.3）％，5±mol为（78．7±2．7）％]，与saline组比较差异有统计学意义（P〈0．05）；Glu＋Mor组逃避域值比最大值为（130±4）％，显著高于G1u组（P〈0．05）；Glu＋NLX＋Mor组最大值为（81±6）％，低于Glu＋Mor组（P〈0．05）；Cap＋Mot最大值为（203±10）％，显著高于Cap组（P〈0．05）；Cap＋NLX＋Mor组最大值为（89±9）％，低于Cap＋Mor组（P〈0．05）。结论谷氨酸受体参与末梢神经痛觉传递，激活阿片受体可以阻止外源性和内

Intraplantar Morphine Prevents the Decrease of the Rate of Thermal Withdrawal Latencies Evoked by Glutamate and Capsaicin

Objective To explore the effects of intraplantar administration of morphine on the decrease of the rate of thermal withdrawal latencies of paws induced by intraplantar glutamate and capsaicin, and the interaction between glutamate receptors and opioid receptors in pain transmission in peripheral afferents. Methods One hundred and twenty-two SD rats were divided at random into twelve groups, and each group consisted of ten animals. Behavioral assessments were used to detect the thermal withdrawal latencies of paws in Sprague-Dawley rats. 15 min, 1 h,2 h, 3 h,4 h,5 h,6 h after some drugs injection into the normal control group （no drug used）,saline （saline group）, glutamate（Glu group）, eapsaicin （Cap group）, morphine（Mot group）, naloxone （NLX group）, glutamate ＋ morphine （Glu ＋ Mor group）, glutamate ＋ naloxone （Glu ＋ NLX group）, glutamate＋ naloxone＋ morphine （ Glu ＋ NLX ＋Mor group）, capsaicin ＋ morphine （Cap ＋ Mor group）, capsaicin ＋ naloxone （Cap ＋ NLX group）, capsaicin ＋ naloxone ＋ morphine （ Cap ＋ NLX＋Mor group）. The thermal withdrawal latencies of paws were tested. Results The thermal withdrawal latencies of left paw was（11. 7±0.29）s for the normal control group, which of right paw was（11. 5±0.4）s and the rate of these was 100% ;the rate of left-right paws was 100% for saline group,Mor group,NLX group,respectively. There were no statistic significant among the three groups（P〉0.05）;the greatest decreases happened to 15-180 min in Cap group （66.4± 3.9）% for 150 nmol;（70±4.3）% for 300 nmol. pared with saline group（P〈0. 05） ;the greatest There were remarkable statistic significant comdecreases occurred to 15-120 min in Glu group （85.9±1.3） % for 1.5μmol; （78.7±2.7）% for 5μmol. There were remarkable statistic significant compared with saline group（P〈0.05） ; the greatest value in Glu＋ Mor group was （130± 4）% ,which was higher than that in Glu group （P〈0.05）;the greatest value