naltrexazone and Pruritus
naltrexazone has been researched along with Pruritus* in 1 studies
Other Studies
1 other study(ies) available for naltrexazone and Pruritus
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Scratching behavior and Fos expression in superficial dorsal horn elicited by protease-activated receptor agonists and other itch mediators in mice.
Protease-activated receptor (PAR)-2 and PAR-4 are implicated in nonhistaminergic itch. We investigated dose dependence, tachyphylaxis, and cross-tachyphylaxis of itch-associated scratching elicited by intradermal injections of PAR-2 and PAR-4 agonists, serotonin (5-hydroxytryptamine, 5-HT), and histamine in ICR mice, as well as mu-opioid modulation of PAR-2 agonist-evoked scratching. Each agent elicited dose-related increases in scratch bouts. Scratching elicited by the PAR-4 agonist and histamine both exhibited significant tachyphylaxis but no cross-tachyphylaxis with each other. Scratching evoked by 5-HT did not exhibit significant tachyphylaxis but did exhibit significant cross-tachyphylaxis to scratching evoked by the PAR-2 and PAR-4 agonists and histamine. Naltrexone and high-dose morphine (10 mg/kg) attenuated PAR-2 agonist-evoked scratching, whereas lower dose morphine (1 mg/kg) had no effect. High-dose morphine also significantly increased circling behavior, which may have interfered with scratching. The PAR-2 agonist and 5-HT produced overlapping distributions of Fos-like immunoreactivity in the superficial dorsal horn. These results indicate that PAR-2 and PAR-4 agonists, histamine, and 5-HT elicit itch-related scratching and activate superficial dorsal horn neurons that may participate in scratch reflex and ascending itch signaling pathways. Topics: Animals; Behavior, Animal; Capsaicin; Histamine; Injections, Intradermal; Mice; Morphine; Naltrexone; Oligopeptides; Posterior Horn Cells; Proto-Oncogene Proteins c-fos; Pruritus; Receptor, PAR-2; Receptors, Opioid, mu; Receptors, Proteinase-Activated; Serotonin; Spinal Cord; Tachyphylaxis | 2009 |