The use of rat EMG to quantify vascular pain

<p>Objective: Anticancer drugs are often administered intravenously. The vascular pain caused by this administration can be said to be side effects of anticancer drugs, and in consideration of the QOL of patients, treatment that “reduce pain” is required. However, it has not been easy to predict and evaluate pain due to intravenous administration using animal model. Therefore, we tried to quantify the pain using the electromyogram generated during vascular pain in rats.</p><p>Methods: Rats (Slc: SD, male, aged 10 to 12) were anesthetized with Secobarbital Sodium (50 mg/kg, ip) and a bipolar stainless electrode was inserted into the semitendinosus muscle, ground electrode was placed subcutis of head region of rat, and the EMG signals were recorded. An indwelling catheter for drug administration was anterogradely cannulated into the femoral circumflex artery. After inserting bipolar electrode, the toes of the rat hind limbs were strongly pinched, and it was confirmed that the EMG increased. After confirming that the EMG was stable, administration of the test solution to the femoral circumflex artery was started.</p><p>Results and discussions: No increase in EMG amplitude was observed during saline administration. On the other hand, administration of gemcitabine increased the EMG amplitude. In addition, pretreatment with fentanyl suppressed the increase in the EMG amplitude after administration of gemcitabine. The results of this study greatly suggested the possibility of quantifying vascular pain, and that the method was useful assessment system.</p>