The Novel Role of Opioid μ-receptors in Gastroenterology

Constipation and gastrointestinal dysmotility are common problems in critical care patients. The cancer patients often suffer from pain and are alleviated with opioid analgesics, which attenuate gastrointestinal (GI) motility and result in adverse outcomes. Although opioid μ-receptors have critical influence on gastroenterology, the novel role of opioid μ-receptors in opiate-induced constipation (OIC) remains obscure. Thus, some peripheral opiate agonists are applied to investigate the involvement of opioid μ-receptors in OIC and their possible mechanism(s). The activation of opioid μ-2 receptors seems associated with OIC induced by opioid analgesics. It is meaningful that a novel target is provided for handling of OIC in cancer patients receiving chronic opioid therapy.