Pharmacol Rep
-
Prolonged morphine treatment leads to antinociceptive tolerance. Suppression of spinal astrocytes or d-amino acid oxidase (DAAO), an astroglial enzyme catalyzing oxidation of d-amino acids, has reversed morphine antinociceptive tolerance. Since the astrocyte-DAAO pathway generates hydrogen peroxide, an agonist of the TRPA1 channel expressed spinally on nociceptive nerve terminals and astrocytes, we tested a hypothesis that the spinal TRPA1 contributes to antinociceptive tolerance to prolonged spinal morphine treatment. ⋯ Antinociceptive morphine tolerance and up-regulation of spinal DAAO were attenuated in morphine-treated animals by blocking the spinal TRPA1. This finding suggests that spinal TRPA1 may contribute, at least partly, to facilitation of morphine antinociceptive tolerance through mechanisms that possibly involve TRPA1-mediated up-regulation of the astroglial DAAO, a generator of hydrogen peroxide, a pronociceptive compound acting also on TRPA1.
-
The purpose of the experiment was to assess interactions of dopamine with propranolol as an infiltrative anesthetic. ⋯ The preclinical data showed that dopamine produced a lesser potency but a comparable duration of cutaneous analgesia compared to propranolol. Adding dopamine to propranolol potentiated and prolonged propranolol's cutaneous analgesic effect.
-
The purposes of this study were to evaluate the co-administration of clonidine with memantine and to determine whether it has a peripheral action in intensifying cutaneous analgesia. ⋯ Our resulting data showed that memantine displayed more potent cutaneous analgesia than lidocaine. Co-administration of memantine or lidocaine with clonidine increased the potency and duration of the cutaneous analgesia. Clonidine intensified the effects of lidocaine promoting cutaneous analgesia than added to memantine.
-
Opioid-induced cough during induction of general anesthesia is a common phenomenon. Dezocine, a partial μ-receptors agonist and κ-receptors antagonist, has been documented effectively suppressing fentanyl-induced cough in general anesthesia induction. However, the effect of dezocine on sufentanil-induced cough is still unknown. ⋯ The results of current study suggest that administration of Dezocine 0.1mg/kg may effectively prevent the occurrence and reflex degree of sufentanil-induced irritating cough in general anesthesia induction in patients.
-
In the present study we determined the role of transient receptor potential V1 channel (TRPV1) and acid-sensing ion channel 3 (ASIC3) in chronic nociception. ⋯ Data suggest that TRPV1 and ASIC3 participate in the development and maintenance of long-lasting secondary allodynia and hyperalgesia induced by formalin in rats. The use of TRPV1 and ASIC3 antagonists by peripheral administration could prove useful to treat chronic pain.