Izumi H, Hayashi S, Karita K
Department of Physiology, Tohoku University School of Dentistry, Sendai, Japan.
Life Sci. 1988;42(16):1529-35. doi: 10.1016/0024-3205(88)90010-0.
The effects of subcutaneous (s.c.) administration of compound 48/80 (a well known histamine liberator) on latency to thermoalgesic stimulus, hematocrit (Hct) and plasma levels of beta-endorphin-like immunoreactivity (beta-END-LI) were investigated in male rats. The s.c. administration of compound 48/80 in doses ranging from 0.5 to 5.0 mg/kg into the rats produced significant analgesia in the hot plate test and increased Hct in a dose-dependent manner. Concomitant variation was observed between the analgesia and the increase of Hct. This analgesic effect, but not the increase of Hct, was diminished by pretreatment with the opiate receptor antagonist, naloxone (5 mg/kg, s.c.). A significant increase of plasma beta-END-LI was observed by s.c. injection of compound 48/80. Together with a previous finding that compound 48/80 induced-hypovolemia increases the renin release from kidney and then causes water intake in the rats, it is suggested that s.c. administration of compound 48/80 induced analgesia mediated through stimulation of an opioid system, may be closely related to stimulation of the renin-angiotensin system.
在雄性大鼠中，研究了皮下注射化合物48/80（一种著名的组胺释放剂）对热痛觉刺激潜伏期、血细胞比容（Hct）以及β-内啡肽样免疫反应性（β-END-LI）血浆水平的影响。给大鼠皮下注射剂量范围为0.5至5.0毫克/千克的化合物48/80，在热板试验中产生了显著的镇痛作用，并以剂量依赖的方式增加了Hct。在镇痛作用和Hct增加之间观察到了伴随变化。用阿片受体拮抗剂纳洛酮（5毫克/千克，皮下注射）预处理可减弱这种镇痛作用，但不会减弱Hct的增加。皮下注射化合物48/80后，观察到血浆β-END-LI显著增加。结合之前的一项发现，即化合物48/80诱导的血容量减少会增加大鼠肾脏中的肾素释放，进而导致大鼠饮水，提示皮下注射化合物48/80诱导的通过刺激阿片系统介导的镇痛作用，可能与肾素-血管紧张素系统的刺激密切相关。
