The aim of this paper is to study the synergistic anti-analgesic effect of angiotensin II (Ang II) plus cholecystokinin octapeptide (CCK-8). Our previous studies have shown that both CCK-8 and Ang II are potent anti-opioid substances. Intracerebroventricular (i.c.v.) injection of CCK-8 or Ang II dose-dependently antagonizes morphine-induced analgesia (MIA). In the present study, we observed the combined effect of CCK-8 and Ang II in antagonizing MIA. CCK-8 and Ang II were injected intracerebroventricularly to rats in various proportions and doses. The results were analyzed with isobolographic analysis. Combined injection of CCK-8 and Ang II in a ratio of 1 ng: 2.5 microg or 1 ng: 5 microg produced significantly greater effect in antagonizing MIA. The ED(50) of the two ratios are only 18.5% and 27.5%, respectively, of the theoretical dose of simple addition. We conclude that CCK-8 and Ang II used in such dose ratios may antagonize MIA synergistically.

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Objective — To design a detection instrument for detecting the quality of radiofrequency ablation electrode, which can quickly detect the physical properties of radiofrequency ablation electrode. Methods — The DC constant current source is introduced to measure the small resistance, test whether the thermocouple is well connected, and measure the resistance between the positive and negative wires of the thermocouple at the plug (1-core and 2-core) to determine whether the thermocouple is well connected. The resistance of the good product is about 40Ω. Detect whether the inner tube and outer tube of RF ablation are in good physical contact through resistance, and judge whether there is physical contact between the inner tube and outer tube by detecting the resistance between the positive conductor of thermocouple (2 cores) and RF connecting wire (3 cores). When in good contact, the resistance is about 0.5 Ω; Measure the short circuit between 4~8 cores of the plug and judge whether the code is correct. The measurement method of pipeline absolute tightness is adopted to detect the change of pipeline pressure. Results — The developed radiofrequency ablation electrode detector can accurately measure the resistance, circuit and pipeline tightness of radiofrequency ablation, and can meet the requirements of detection accuracy. Conclusion — The quality of the prototype is stable and can meet the needs of users.