Chronic methamphetamine administration reduces histamine-stimulated phosphoinositide hydrolysis in mouse frontal cortex.
In the present study, it was hypothesized that in vivo pretreatment with repeated methamphetamine would alter the agonist-stimulated phosphoinositide hydrolysis in mouse frontal cortical slices. Male ICR mice that received the methamphetamine injection (1.0mg/kg, intraperitoneally) once a day for five consecutive days showed behavioral sensitization to the same dose of methamphetamine 5 days after the last injection of the initial chronic treatment regimen (test day 10). On test day 10, the reduction of histamine (0.1-1.0mM)-stimulated phosphoinositide hydrolysis in the mouse frontal cortex was observed. The reduction was specific to histamine, but not to norepinephrine (10 microM-0.1mM) or L-glutamate (0.1-0.5mM). The reduction occurred without any change in the expression level of histamine H(1) receptor mRNA. The reduction recovered 25 days after the last injection of the initial chronic treatment regimen (test day 30). The direct application to the slices of a pharmacologically effective concentration of methamphetamine in vitro (10 microM) did not alter the histamine signal transduction. The present results suggest that the reduction is probably one of neuroadaptations in the frontal cortex contributing to behavioral sensitization.
Kitanaka
Junichi
J
Department of Pharmacology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan. kitanaka-hyg@umin.ac.jp
Kitanaka
Nobue
N
Takemura
Motohiko
M
D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000494:pharmacology; D005625:Frontal Lobe / Q000187:drug effects* / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology*; D006868:Hydrolysis; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage* / Q000494:pharmacology; D051379:Mice; D009043:Motor Activity; D009638:Norepinephrine / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism*; D011897:Random Allocation; D011969:Receptors, Histamine H1 / Q000235:genetics / Q000378:metabolism
D000697:Central Nervous System Stimulants; D010716:Phosphatidylinositols; D011969:Receptors, Histamine H1; D008694:Methamphetamine; D006632:Histamine; D009638:Norepinephrine