These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Role of nitric oxide in the rat hippocampal CA1 in morphine antinociception.
    Author: Hashemi M, Karami M, Zarrindast MR, Sahebgharani M.
    Journal: Brain Res; 2010 Feb 08; 1313():79-88. PubMed ID: 19931515.
    Abstract:
    In the present study, the effects of intra-hippocampal CA1 injections of l-arginine, a nitric oxide (NO) precursor and N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, on morphine-induced antinociception in rat formalin test were investigated. To induce inflammation pain, formalin (50 microl at 2.5%) was injected into the right hind-paw of male Wistar rats prior to testing. Morphine (3-9 mg/kg) was injected intraperitoneally (i.p.) 10 min before injection of formalin. The present study shows that administration of L-arginine (0.08, 0.15, 0.3, 1.0 and 3.0 microg/rat), but not L-NAME (0.15, 0.3 and 1.0 microg/rat), 5 min before formalin injection reversed morphine-induced antinociception at the early phase of formalin test. However, both drugs blocked morphine antinociception at the late phase of the test, but none of these drugs elicited any response by themselves at the tonic phase when injected alone. Moreover, the response to l-arginine was potentiated by L-NAME pre-treatment. It should be noted that a single injection of both L-arginine and L-NAME showed nociceptive effect at the early phase of the test. The present study reveals an expression of NADPH-diaphorase in the rat brain samples administered by L-arginine. Expression of NADPH-d is decreased in the samples which were pre-injected with L-NAME. This study suggests NO participation in the rat hippocampal CA1 area in morphine-induced antinociception.
    [Abstract] [Full Text] [Related] [New Search]