Effects of methoxamine and alpha-adrenoceptor antagonists, prazosin and yohimbine, on the sleep-wake cycle of the rat.

A study was carried out on the effects of methoxamine, prazosin, and yohimbine on the sleep-wake cycle in rats prepared for chronic sleep recordings. Methoxamine (4-8 mg/kg), an alpha 1-adrenoceptor agonist, induced a dose-related increase in wakefulness (W) and a decrease in slow-wave sleep (SWS) and REM sleep (REMS). Prazosin (0.125-1 mg/kg), which selectively blocks alpha 1-adrenoceptors, modified only slightly the amount of time spent in W and SWS, and consistently decreased REMS values. Prazosin (0.5 mg/kg) reversed the effects of methoxamine, decreasing W and increasing sleep. Yohimbine (3 mg/kg), which blocks alpha 2-adrenoceptors, augmented W and diminished sleep. Methoxamine (4 mg/kg) in animals pretreated with yohimbine (3 mg/kg) induced a further decrease of SWS and REMS and an increase of W. Thus, pharmacological activation of alpha 1- or blocking of alpha 2-adrenoceptors appears to decrease sleep and increase W. Further, blocking of alpha 1-adrenoceptors decreases REMS. Rapid eye movement sleep depression by the alpha 1-agonist or the alpha 1-antagonist is tentatively ascribed to a critical change in noradrenergic transmission in the brain.

Primer premolar maxilar con tres conductos. A propósito de un caso / Maxillary first premolar with three canals. A case report

El éxito en el tratamiento de conductos radiculares va a depender entre otras cosas, del conocimiento de la morfología interna y externa de los dientes. Los primeros premolares maxilares presentan una amplia variación en la configuración de las raíces y los conductos radiculares, que debemos estudiar para el correcto diagnóstico y plan de tratamiento. Presentamos un caso clínico de un primer premolar superior con dos raíces y tres conductos

The success of root canal treatment depends on the knowledge of the internal and external tooth morphology among other things. Maxillary first premolars are said to exhibit large variation in root canal morphology we must know to make a proper diagnosis and treatment plan. This article reports a case of an upper left first premolar with two roots and three Canals

Effects of a-fluoromethylhistidine on sleep and wakefulness in the rat. Short note.

The histamine synthesis inhibitor a-fluoromethylhistidine (a-FMH, 50 mg/kg, i.p.) significantly reduced wakefulness (W) and light sleep and increased slow wave sleep (SWS) and REM sleep during the light period in rats housed under 12 h light/12 h dark conditions (12L/12D). When animals were housed under 16 h light/8 h dark (16L/8D) they remained awake for a longer period of time during the dark as compared to the 12L/12D lighting cycle. Under this condition a-FMH 50 mg/kg significantly decreased W and increased SWS. Our results tend to indicate that histamine intervenes in sleep-wakefulness regulation. In addition, histamine could be partly involved in the abnormally increased incidence of W observed during the dark in rats housed under 16L/8D conditions.

Programa de apoyo y asesoramiento para familias con enfermo crónico y su repercusión en la gestión del proceso de hemodiálisis / No disponible

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