阿片类药物对胃肠道功能的作用-抑制消化腺分泌导致便秘 Action of opiates on gastroinstestinal function-reduces grand secretions causes constipation

摘要
阿片类肽和阿片类受体分布在胃肠道(GI)，表明内源性阿片类物质外周释放可能调节胃肠道运动和分泌功能。

动物研究表明，阿片类药物对肠道运动的影响取决于所涉及的受体亚纲的性质、种类和肠部。

大多数阿片类药物具有选择性或显著的mu激动剂活性，通过中枢作用抑制胃动力和延缓胃排空;系统注射时，delta和kappa激动剂无活性。

阿片类药物延迟人类、大鼠和其他物种肠道运输的效果与抑制(大鼠)或刺激(狗和人)肠道收缩作为早产儿iii型序列有关。

吗啡的便秘效应可能主要是由于其对结肠运动的作用。吗啡通过中枢和外周部位的作用刺激人体结肠运动。结肠运动的增加和结肠运输的延迟与加强紧张收缩和减少推进波有关。

delta和mu受体都参与阿片类物质对结肠运动的刺激作用，而kappa受体主要通过中枢作用抑制结肠收缩。

阿片类药物对胃酸分泌的影响仍有争议，但已证实阿片类药物在降低大鼠胰腺分泌方面具有中枢作用。阿片类药物还通过对肠神经系统和中枢神经系统的作用抑制肠道分泌物。

所有这些结果都证实了阿片类肽在控制肠道蠕动和分泌物方面具有重要的生理作用的假设，这些作用解释了阿片类物质对消化道的大部分药理作用。

Action of opiates on gastrointestinal function.

Abstract

Opioid peptides and opioid receptors are distributed along the gastrointestinal (GI) tract, indicating endogenous opiates released peripherally may modulate GI motor and secretory functions.

Animal studies have revealed that the effects of opiates on gut motility depend on the nature of the subclasses of receptor involved, the species and the part of bowel.

Most opiates that have a selective or predominant mu agonist activity inhibit gastric motility and delay gastric emptying by acting centrally; delta and kappa agonist are inactive when injected systemically.

The effect of opiates in delaying intestinal transit observed in man, rat and other species is related to an inhibition (rat) or a stimulation (dog and man) of intestinal contractions as premature phase III-like sequences.

The constipating effects of morphine probably result mainly from its action on colonic motility. Morphine stimulates colonic motility in humans by action on both central and peripheral sites.

This increase in colonic motility and the delay in colonic transit is associated with a reinforcement of tonic contractions and reduced propulsive waves.

Opioid peptides have been shown to participate in the colonic motor response to eating in man and animals.

Both delta and mu receptors are involved in the stimulatory effects of opiates on colonic motility, while kappa receptors inhibit colonic contractions, mainly by acting centrally.

The effects of opiates on gastric acid secretion are still controversial but it has been well demonstrated that opiates act centrally to reduce pancreatic secretion in rats.

opiates also inhibit intestinal secretions via an action on the enteric nervous system as well as in the CNS.

All these results reinforce the hypothesis that opioid peptides have a major physiological role in the control of gut motility and secretions, and these actions explain most of the pharmacological effects of opiate substances on the digestive tract.