Facilitation of opiate-and enkephalin-induced motor activity in the mouse by phenytoin sodium and carbamazepine

In the first experiment, adult male Swiss-Webster mice were systemically injected with a standard dose of morphine. Compared to the influence of vehicle, the motor activity of morphine-injected mice was increased. Neither phenytoin sodium nor carbamazepine alone facilitated motor activity, but pretreatment with both drugs further facilitated the increased motor activity produced by morphine. In a second experiment, mice were injected centrally with a long-acting analog of leu-enkephalin. It also increased motor activity in comparison with vehicle. Again, both phenytoin sodium and carbamazepine further facilitated this response. Both experiments suggest a facilitatory interaction between some aspects of these anticonvulsants and opiate-induced motor activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46410/1/213_2004_Article_BF00491980.pd

Effects of selected opioid agonists and antagonists on DMT-and LSD-25-induced disruption of food-rewarded bar pressing behavior in the rat

Several opioid agonists and antagonists interact with N,N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) in adult male Holtzman rats trained on a positive reinforcement, fixed ratio 4 (FR 4 ) behavioral schedule, i.e., a reward of 0.01 ml sugar-sweetened milk was earned on every fourth bar press. DMT (3.2 and 10.0 mg/kg) and LSD (0.1 mg/kg) given IP with 0.9% NaCl pretreatment, disrupted food-rewarded FR4 bar pressing. Animals were pretreated IP (10–15 min) with predetermined, behaviorally noneffective doses of morphine, methadone, naltrexone, and the (+)-and (-)-enantiomers of naloxone prior to receiving DMT or LSD. Dose-dependent effects were shown with opioid agonist pretreatment. Morphine (0.32–1.0 mg/kg) and methadone (0.32 mg/kg) significantly antagonized the bar pressing disruption induced by DMT and LSD. Larger doses of morphine (3.2 mg/kg) and methadone (1.0–3.2 mg/kg) potentiated only LSD-induced effects, with no effect on DMT-treated groups. The opioid antagonists (-)-naloxone and naltrexone potentiated the disruption of bar pressing induced by DMT and LSD. Failure of (+)-naloxone to potentiate the DMT effects was attributed to a stereospecific opioid antagonist effect of (-)-naloxone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46425/1/213_2004_Article_BF00432428.pd

Valor prognostico dos teores de potassio e sodio no liquido cefalorraquiano e no sangue de doentes em coma: estudo de 55 casos

Trata-se de um estudo prospective) com 55 doentes, tomados ao acaso, independentemente da idade, sexo, grau de coma ou da sua etiologia. Foi medida a concentração do potássio e do sódio no LCR e no soro sangüíneo destes doentes, visando a um critério auxiliar de avaliação prognostica. Os resultados mostraram que as taxas elevadas de potássio no LCR são indicativo de mau prognóstico. No texto são abordados os aspectos fisiopatológicos dos achados