| First Author | Mobarakeh JI | Year | 2002 |
| Journal | Neuropharmacology | Volume | 42 |
| Issue | 8 | Pages | 1079-88 |
| PubMed ID | 12128009 | Mgi Jnum | J:179575 |
| Mgi Id | MGI:5302657 | Doi | 10.1016/s0028-3908(02)00058-8 |
| Citation | Mobarakeh JI, et al. (2002) Enhanced antinociception by intrathecally-administered morphine in histamine H1 receptor gene knockout mice. Neuropharmacology 42(8):1079-88 |
| abstractText | We previously reported that histamine H(1) receptor gene knockout mice (H1KO) showed lower spontaneous nociceptive threshold to pain stimuli when compared to wild-type mice. The objective of the present study was to examine the antinociceptive effect of intrathecally-administered morphine in H1KO mice. The antinociceptive effects of morphine were examined using assays for thermal (tail-flick, hot-plate, paw-withdrawal), mechanical (tail-pressure) and chemical nociception (formalin and capsaicin tests) using H1KO and wild-type mice. In these nociceptive assays, intrathecally-administered morphine produced significant antinociceptive effects in wild-type mice. The antinociceptive effect produced by intrathecally administered morphine was enhanced in the knockout mice. We also examined the effect of an histamine H(1) receptor antagonist, an active (d-) isomer of chlorpheniramine, on morphine-induced antinociception in ICR mice. The intrathecal co-administration of d-chlorpheniramine enhanced the effect of morphine in all nociceptive assays examined. The pharmacological experiments using d-chlorpheniramine further substantiate the evidence for the histamine H(1) receptor-mediated suppression of morphine-induced antinociception. These results suggest that existing H(1) receptors play an inhibitory role in morphine-induced antinociception at the spinal cord level. |
