Naunyn-Schmiedeberg's archives of pharmacology
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Naunyn Schmiedebergs Arch. Pharmacol. · Aug 2009
Effects of a single postnatal methamphetamine administration on NMDA-induced seizures are sex- and prenatal exposure-specific.
The aim of our study was to reveal whether acute methamphetamine (MA) administration changes the sensitivity to seizures induced by N-methyl-D-aspartate (NMDA) in prenatally MA-exposed adult rats. Adult rats with respect to sex and female estrous cycle (prenatally MA-exposed, prenatally saline-exposed, and controls) were divided into groups with acute MA (1 mg/kg) or without acute drug administration (saline injection). Intraperitoneal administration of 250 mg/kg of NMDA was used as a seizure model. ⋯ In addition, males displayed decreased susceptibility to NMDA-induced seizures relative to females regardless of their estrous cycle. Our study suggests that acute MA exposure changes susceptibility to NMDA-induced seizures in respect of prenatal exposure and sex. However, it seems that the effect of prenatal exposure is not induced by the drug per se but rather by the repeated injection exposure that causes prenatal stress.
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Naunyn Schmiedebergs Arch. Pharmacol. · Aug 2009
Comparative StudyTopical antiseptics for the treatment of sore throat block voltage-gated neuronal sodium channels in a local anaesthetic-like manner.
Lozenges for the treatment of sore throat provide relief of discomfort in cases of oral inflammation. This effect has not been fully explained so far. Here, we have examined the proposition that key components of pharmaceutical preparations for the treatment of sore throat which are routinely regarded antiseptics might have sodium channel-blocking, i.e. local anaesthetic-like effects. ⋯ Estimates for the inactivated state affinity were 1.88 and 35 microM for hexylresorcinol and amylmetacresol, respectively. Hexylresorcinol and amylmetacresol are 10-20 fold more potent than the local anaesthetic lidocaine in blocking sodium inward current. Both drugs show an increased effect at depolarised membrane potentials or in conditions of high-frequency discharges.