Melanocortin-4 receptor expression in autonomic circuitry involved in gastric function.

Several studies have shown that CNS provides the regulation of gastric functions. Recent evidence indicated that the activation of melanocortin 4 receptors (MC4R) in brain nuclei played an important role in modulating gastric activity. This study was designed to assess whether MC4R signaling existed in autonomic circuitry modulated the activity of stomach by a virally mediated transsynaptic tracing study. Pseudorabies virus (PRV)-614 was injected into the ventral stomach wall in adult male MC4R-green fluorescent protein (GFP) transgenic mice (n = 5). After a survival time of 5 days, the mice were assigned to humanely sacrifice, and spinal cords and caudal brainstem were removed and sectioned, and processed for PRV-614 visualization. Neurons involved in the efferent control of the stomach were identified following visualization of PRV-614 retrograde tracing. The neurochemical phenotype of MC4R-GFP-positive neurons was identified using fluorescence immunocytochemical labeling. PRV-614/MC4R-GFP dual labeled neurons were detected in spinal IML and the dorsal motor nucleus of the vagus nerve (DMV). Our findings support the hypothesis that MC4R signaling in autonomic circuitry may participate in the modulation of gastric activity by the melanocortinergic-sympathetic pathway or melanocortinergic-parasympathetic pathway.

[Hemodynamic variations during tracheal intubation with intubating laryngeal mask airway versus direct laryngoscope in hypertensive patients].

OBJECTIVE: To compare the variations of cardiovascular responses and vascular angiotensin II (AngII) in hypertensive patients during tracheal intubation with intubating laryngeal mask airway (ILMA) versus direct laryngoscope (DLS). METHODS: A total of 120 hypertensive patients undergoing abdominal surgery were randomly divided into 2 groups, i.e.intubating laryngeal mask airway (Group I) and direct laryngoscope (Group D).Variations of invasive arterial blood pressure and angiotensin II were compared between two groups before and after intubation. RESULTS: The variations of cardiovascular responses and vascular angiotensin II (AngII) during tracheal intubation used of ILMA (T4) and DLS (T4) in an instant, tracheal intubation were immediately accomplished in two groups (T5). The variations of group I were significantly lower than those of group D (P < 0.05). And statistical significance existed between two groups. CONCLUSION: Tracheal intubation with intubating laryngeal mask airway (ILMA) can significantly reduce violent cardiovascular reactions and avoid cardiovascular accidents.