Introduction: The relation between morphine and nitric oxide release has been shown. Due to important role of nitric oxide in regulation of skin blood flow, the aim of this study was to investigate the effect of nitric oxide synthase inhibitor (L-NAME) and nitric oxide synthesis precursor (L-arginine) on skin blood flow of intact and morphine-dependent rats. Methods: Skin blood flow of hind pa...

Background: Role of nitric oxide (NO) in morphine-induced conditioned place preference (CPP) has already been proposed in the rat medial septum (MS), but no molecular evidence has been provided to clear this fact. Methods: Effects of intraseptal injections of L-arginine and/or NG-nitro-L-arginine methyl ester (L-NAME) on morphine place conditioning in Wistar rats were examined. Morphine (2.5-7....

Human plasma contains low, but physiologically significant, concentrations of morphine that can increase following trauma or exercise. We now demonstrate that normal, human white blood cells (WBC), specifically polymorphonuclear cells, contain and have the ability to synthesize morphine. We also show that WBC express CYP2D6, an enzyme capable of synthesizing morphine from tyramine, norlaudanoso...

Heroin is an illegal drug and monitoring heroin use is important in rehabilitation, pain management services, and workplace employment testing. In humans, heroin is rapidly converted to 6-acetylmorphine (6AM), which is quickly hydrolyzed to morphine. Morphine glucuronide is the major metabolite of heroin in urine (1 ). However, 6AM is a unique metabolite of heroin and is considered the definiti...

introduction: drugs of abuse such as nicotine and morphine used systemically by addicts produce their effects via the mesolimbic dopaminergic pathway. furthermore, evidence indicates that some behavioral effects of nicotine and morphine are mediated by nitric oxide (no). based on these observations, the aim of the present study was to investigate the effects of intra-nucleus accumbens (nac) inj...

Key pecking by 3 pigeons was maintained by a multiple fixed-ratio 10, fixed-ratio 30, fixed-ratio 90 schedule of food presentation. Components differed with respect to amount of reinforcement, such that the unit price was 10 responses per 1-s access to food. Acute administration of morphine, l-methadone, and cocaine dose-dependently decreased overall response rates in each of the components. Wh...

objective(s):dependence and tolerance to opioid analgesics are major problems limiting their clinical application. a-terpineol is a monoterpenoid alcohol with neuroprotective effects which is found in several medicinal plants such as myrtus communis, laurus nobilis, and stachys byzantina. it has been shown that some of these medicinal plants such as s. byzantina attenuate dependence and toleran...

The ability of pretreatment by the selective cholecystokinin-B (CCK(B)) receptor antagonist L-365,260 (0.2 mg/kg s.c.) to prevent the development of tolerance to the antinociceptive action of morphine was evaluated by a well-established rat model of unilateral peripheral mononeuropathy. The 4-day pretreatment regimens (saline, L-365,260 or morphine alone, or with the combination of L-365,260 an...