Ketamine-induced peripheral analgesia in rats
Abstract
AIM: To examine whether ketamine may directly act at peripheral nociceptors to
produce analgesia.
METHODS: Wistar rats were anesthetized with urethane. As a nociceptive flexion
reflex (FR), C responses from the posterior biceps semitendinosus (PBST) muscle
was evoked by electrical stimulation (2 ms, 80 V, 2-3 pulses, 0.5 Hz) via a pair
of stainless steel needles inserted subcutaneously applied to the two toes of
ipsilateral hindpw.
RESULTS: Subcutaneous injection of ketamine (36 mmol.L-1, 5 microL) into the
ipsilateral hindpaw produced an inhibition of C responses. At 9 min after
application of ketamine, injection of naloxone (1%, 5 microL) into the same area
annulled ketamine-induced inhibition.
CONCLUSION: Ketamine as a dissociate anesthetic acts on peripheral nociceptors to
produce analgesia, which is related to activity of peripheral opioid receptors.
Keywords:
produce analgesia.
METHODS: Wistar rats were anesthetized with urethane. As a nociceptive flexion
reflex (FR), C responses from the posterior biceps semitendinosus (PBST) muscle
was evoked by electrical stimulation (2 ms, 80 V, 2-3 pulses, 0.5 Hz) via a pair
of stainless steel needles inserted subcutaneously applied to the two toes of
ipsilateral hindpw.
RESULTS: Subcutaneous injection of ketamine (36 mmol.L-1, 5 microL) into the
ipsilateral hindpaw produced an inhibition of C responses. At 9 min after
application of ketamine, injection of naloxone (1%, 5 microL) into the same area
annulled ketamine-induced inhibition.
CONCLUSION: Ketamine as a dissociate anesthetic acts on peripheral nociceptors to
produce analgesia, which is related to activity of peripheral opioid receptors.