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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Adrenergic alpha-Antagonists, Animals, Dose-Response Relationship, Drug, Down-Regulation, Drug Evaluation, Preclinical, Endotoxemia, Gastric Emptying, Gastrointestinal Motility, Gastrointestinal Transit, Intestine, Small, Lipopolysaccharides, Male, Mice, Mice, Inbred BALB C, Nitric Oxide Synthase Type II, Yohimbine.
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Does the alpha2-adrenergic receptor antagonist yohimbine improve endotoxin-induced inhibition of gastrointestinal motility in mice? Context: Sepsis inhibits gastrointestinal motility. Although the exact mechanism of this is unclear, lipopolysaccharide is known to activate macrophages in the gastrointestinal wall, which upregulate their expression of inducible nitric oxide synthase (iNOS). This leads to an increased production of nitric oxide, which relaxes the gastrointestinal muscles. We studied endotoxaemic mice to determine whether yohimbine improved delayed gastric emptying and gastrointestinal transit. Male Balb/c mice (n = 49) were randomly allocated to two groups, and either yohimbine 25 microg or saline was injected s.c. Four hours later, mice in each group were further randomly allocated to two groups, and either lipopolysaccharide 100 microg or saline was injected intraperitoneally. Eight hours later, liquid containing fluorescent microbeads was infused into the stomach, and 30 min later, gastric emptying and gastrointestinal transit were measured using flow cytometry. We also studied whether yohimbine given after injection of lipopolysaccharide was effective (n = 22). In another group of mice (n = 32), iNOS in the gastrointestinal tract was measured using western blotting. Lipopolysaccharide significantly inhibited gastric emptying and gastrointestinal transit. Yohimbine, given before or after lipopolysaccharide, significantly attenuated the inhibitory effects of lipopolysaccharide. Lipopolysaccharide increased the expression of iNOS in the small intestine and yohimbine suppressed the effects of lipopolysaccharide.
assistant
In endotoxaemic mice, yohimbine improved delayed gastric emptying and gastrointestinal transit, possibly by downregulating lipopolysaccharide-induced increased expression of iNOS. Final Decision: yes