In vitro and in vivo characterization of the bifunctional μ and δ opioid receptor ligand UFP-505.

Background And Purpose: Targeting more than one opioid receptor type simultaneously may have analgesic advantages in reducing side-effects. We have evaluated the mixed μ opioid receptor agonist/ δ opioid receptor antagonist UFP-505 in vitro and in vivo.

Experimental Approach: We measured receptor density and function in single μ, δ and μ /δ receptor double expression systems.

Nitrous oxide and xenon increase noradrenaline release in the cerebral cortex in vivo and in vitro.

Noradrenaline in the central nervous system plays an important role in regulating physiological functions, and is a key mechanistic component of general anesthesia. The purpose of this present study was to determine if nitrous oxide and xenon modulate noradrenaline release in the cerebral cortex. We performed a series of in vivo and in vitro experiments in rats.

[A case of unanticipated postoperative respiratory distress from cancerous pleural effusion].

A 63-year-old woman with a 2-month history of abdominal distension received diagnostic laparotomy under general anesthesia. The chest X-ray one week preoperatively demonstrated slight left pleural effusion, but she did not show any dyspnea on preanesthetic interview. General anesthesia was induced with propofol, ketamine and fentanyl.

Orexin A decreases ketamine-induced anesthesia time in the rat: the relevance to brain noradrenergic neuronal activity.

Background: Orexins (OXs) regulate wakefulness, and a lack of OX Type-I receptors cause narcolepsy. OX selectively increases norepinephrine (NE) release from rat cerebral cortical slices, and brain noradrenergic neurons are involved in the sleep-wakefulness cycle. Ketamine increases NE release from the rat cerebral cortex.

Interaction between orexinergic neurons and NMDA receptors in the control of locus coeruleus-cerebrocortical noradrenergic activity of the rat.

Several studies suggest that NMDA glutamate receptors may play an important role in the activation of a number of brain regions by orexin (OX). We hypothesized that OX and NMDA receptors may interact with cerebrocortical noradrenergic neuron originating from the locus coeruleus (LC). To test this hypothesis, using rats as experimental animals, we examined (i) in vitro effects of MK801 on OXA-evoked norepinephrine release from rat cerebrocortical slices, (ii) in vivo interaction between OXA and the NMDA receptor antagonist, MK801 on norepinephrine release from the prefrontal cortex assessed using microdialysis and (iii) MK801 and OXA-modulation of the electroencephalogram (EEG).