title: Activation of Peripheral κ-Opioid Receptors Normalizes Caffeine Effects Modified in Nicotine-Dependent Rats during Nicotine Withdrawal.
abstract: The study examined the effect of peripheral (intragastric) ICI-204,448, an agonist of gastric κ-opioid receptors, on the psychostimulating and anxiolytic effects of caffeine in nicotinedependent rats at the stage of nicotine withdrawal. In these rats, the effects of caffeine (10 mg/kg) were perverted. In nicotine-dependent rats, caffeine produced an anxiolytic effect accompanied by pronounced stimulation of motor activity, in contrast to anxiogenic effect induced by caffeine in intact rats without nicotine dependence. During nicotine withdrawal, nicotine-dependent rats demonstrated enhanced sensitivity to nicotine. Intragastric administration of κ-opioid receptor agonist ICI-204,448 normalized the effect of caffeine in nicotinedependent rats. We have previously demonstrated that activation of peripheral κ-opioid receptors inhibited central κ-opioid activity and eliminated manifestations of nicotine withdrawal syndrome in nicotine-dependent rats, e.g. metabolism activation, stimulation of motor activity, and enhancement of food consumption. In its turn, inhibition of central κ-opioid structures activates the brain adenosine system, which can attenuate the caffeine-induced effects in nicotine-dependent rats.
authors: P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia. s-sudakov@nphys.ru.
authors: S K
authors: SK
authors: Sudakov
authors: P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia.
authors: N G
authors: NG
authors: Bogdanova
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D065570:Gastric Absorption / Q000502:physiology; D005753:Gastric Mucosa / Q000378:metabolism; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009538:Nicotine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017473:Receptors, Opioid, kappa / Q000819:agonists* / Q000378:metabolism; D013375:Substance Withdrawal Syndrome / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D014029:Tobacco Use Disorder / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology
chemical_list: D014151:Anti-Anxiety Agents; D000697:Central Nervous System Stimulants; D011759:Pyrrolidines; D017473:Receptors, Opioid, kappa; C060223:ICI 204448; D002110:Caffeine; D009538:Nicotine
keywords: caffeine; elevated plus-maze; endogenous opioid system; motor activity; nicotine