RESUMEN
OBJECTIVE: In this study, we aimed to study the effects of ICI204,448, naloxone methiodide and levocetirizine on the scratching behavior induced by intradermal injection of a ?-opioid antagonist, nor-binaltorphimine (nor-BNI), into the rostral back of ICR mice were investigated. MATERIALS AND METHODS: Male ICR mice weighing 30?35 g were used. The number of scratching episodes were counted for 60 min after i.d. injection of nor-BNI. RESULTS: nor-BNI dose dependently increased in the number of scratching episodes in ICR mice. nor-BNI-induced scratching behavior was inhibited by not only nalfurafine but also ICI204,448, a peripherally selective ?-opioid agonist. Naloxone and naloxone methiodide, a peripherally restricted ?-opioid antagonist, also inhibited nor-BNI-induced scratching behavior. Scratching behavior induced by nor-BNI was inhibited by chlorpheniramine as well as levocetirizine, a third-generation H1 antagonist that does not cross into the CNS. CONCLUSION: These results suggest that scratching behavior induced by this ?-opioid antagonist, nor-BNI, is related to not only central but also peripheral opioid and H1 receptors.
Asunto(s)
Conducta Animal/efectos de los fármacos , Cetirizina/farmacología , Naloxona/análogos & derivados , Naltrexona/análogos & derivados , Antagonistas de Narcóticos/farmacología , Pirrolidinas/farmacología , Animales , Masculino , Ratones , Ratones Endogámicos ICR , Naloxona/farmacología , Naltrexona/farmacología , Compuestos de Amonio Cuaternario/farmacologíaRESUMEN
In this study, we examined the interaction between histamine H1 receptor and µ-opioid receptor in scratching behavior in ICR mice. Both histamine and morphine caused scratching and simultaneous injection of histamine and morphine had an additive effect. Chlorpheniramine and naloxone inhibited histamine-induced scratching behavior. These two drugs also inhibited morphine-induced scratching behavior. Simultaneous injection of chlorpheniramine and naloxone caused a significant inhibition of histamine-induced scratching compared with separate injections. The same findings were also noted for morphine-induced scratching. These results strongly indicate a close relationship between histamine H1 receptor and µ-opioid receptor in scratching behavior in ICR mice.
Asunto(s)
Conducta Animal/efectos de los fármacos , Receptores Histamínicos H1/metabolismo , Receptores Opioides mu/metabolismo , Animales , Clorfeniramina/farmacología , Clorfeniramina/uso terapéutico , Histamina/farmacología , Masculino , Ratones , Ratones Endogámicos ICR , Morfina/farmacología , Naloxona/farmacología , Naloxona/uso terapéutico , Unión Proteica , Prurito/tratamiento farmacológico , Prurito/metabolismoRESUMEN
In order to elucidate the characteristics of scratching behavior in atopic dermatitis from Japanese mice (ADJM) mice, the effects of some antagonists of pruritogens on this behavior were studied. Both male and female ADJM mice showed frequent scratching behavior around the face, abdomen and back. The number of scratching behavior around the face was greater than on the abdomen and back, and scratching behavior in female mice was significantly more frequent than in male mice. Histamine H1 antagonist, chlorpheniramine, p.o., inhibited this behavior potently and dose-dependently. Histamine H1 antagonist with serotonin 5-TH(5-hydroxytryptamine)2 antagonist, cyproheptadine, also inhibited this behavior. However, NK1 antagonist, aprepitant, p.o., had no significant inhibitory effect even at a dose of 100 mg/kg, p.o., Mu antagonist, naloxone, and kappa agonist, nalfurafine, significantly inhibited this behavior at doses of 0.3 mg/kg, s.c., and 0.01 mg/kg, p.o., respectively. Histamine contents in the skin of ADJM mice were significantly higher than in BALB/c mice. These results strongly indicate that scratching behavior in ADJM mice is related with histamine H1, opioid mu and opioid kappa receptors.