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Medical AI Inquiry: You were 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.
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Tone of LES is maintained by
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The correct answer is  Acetylcholine and tachykinins are involved in the LOS contraction acting through acetylcholine M3 and tachykinin NK2 receptors. Nitric oxide can also be involved in the regulation of LOS contraction. Ref: guyton and hall textbook of medical physiology 12 edition page number:443,444,445