The Role of Opioid Receptor on the Analgesic Action of Intrathecal Sildenafil in Rats / 대한통증학회지

BACKGROUND: Intrathecal sildenafil has produced antinociception by increasing the cGMP through inhibition of phosphodiesterase 5. Spinal opioid receptor has been reported to be involved in the modulation of nociceptive transmission. The aim of this study was to examine the role of opioid receptor in the effect of sildenafil on the nociception evoked by formalin injection. METHODS: Rats were implanted with lumbar intrathecal catheters. Formalin testing was used as a nociceptive model. Formalin-induced nociceptive behavior (flinching response) was observed. To clarify the role of the opioid receptor for the analgesic action of sildenafil, naloxone was administered intrathecally 10 min before sildenafil delivery, and formalin was then injected 10 min later. RESULTS: Intrathecal sildenafil produced dose-dependent suppression of flinches in both phases during the formalin test. Intrathecal naloxone reversed the analgesic effect of sildenafil in both phases. CONCLUSIONS: Sildenafil is active against the nociceptive state that's evoked by a formalin stimulus, and the opioid receptor is involved in the analgesic action of sildenafil at thespinal level.

Effect of fetal transplants on functional recovery after spinal cord transecti on in newborn and adult rats / 中华创伤骨科杂志

Objective To study the effect of fetal transplants on the fu nctional recovery after spinal cord transection in new born and adult rats. Meth ods The spinal cord tissue at E14 of a rat fetal was transferred into the hemise ction cavity at lumbar spinal cord in the newborn and adult rats. 4, 8, 12 weeks after the operation, spinal cord tissue morphology, combined behavioral score ( CBS), somatosensory evoked potentials (SEP), and motor evoked potentials (MEP) w ere examined. Results The transplanted tissue survived in the host spinal cord. There was a statistical difference in CBS between the newborn graft group and th e adult graft group. The peak latencies of early waves in SEPs and MEPs of the n ewborn graft group were superior to those of the adult graft group (P