Swain M G, Vergalla J, Jones E A
Liver Diseases Section, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Hepatology. 1993 Sep;18(3):556-8.
Endopeptidase 24.11 (enkephalinase), an enzyme known to be present in plasma and liver, is capable of metabolizing a substantial number of bioactive peptides. We measured plasma endopeptidase 24.11 activity in normal subjects and in patients with chronic hepatocellular disease or chronic cholestatic liver disease. The mean level of plasma endopeptidase 24.11 activity was 13 times higher in cholestatic patients than in controls or patients with hepatocellular disease (p < 0.01). Plasma endopeptidase 24.11 activity in patients correlated closely with traditional serum markers of cholestasis, including levels of alkaline phosphatase, gamma-glutamyltranspeptidase and aminopeptidase (p < 0.01 for all). However, plasma endopeptidase 24.11 activity correlated poorly with serum ALT aminotransferase level (p = NS), indicating that it is not a marker of hepatocellular disease. The lack of overlap between plasma endopeptidase 24.11 activity in cholestatic patients and noncholestatic liver disease controls suggests that this enzyme activity is a useful biochemical marker of cholestasis. In addition, because of the broad spectrum of peptides metabolized by endopeptidase 24.11, increased plasma endopeptidase 24.11 activity may contribute to the pathophysiology of the syndrome of cholestasis.
内肽酶24.11（脑啡肽酶）是一种已知存在于血浆和肝脏中的酶，能够代谢大量生物活性肽。我们测定了正常受试者以及患有慢性肝细胞疾病或慢性胆汁淤积性肝病患者的血浆内肽酶24.11活性。胆汁淤积患者的血浆内肽酶24.11活性平均水平比对照组或肝细胞疾病患者高13倍（p < 0.01）。患者的血浆内肽酶24.11活性与胆汁淤积的传统血清标志物密切相关，包括碱性磷酸酶、γ-谷氨酰转肽酶和氨肽酶水平（所有p值均 < 0.01）。然而，血浆内肽酶24.11活性与血清ALT转氨酶水平相关性较差（p = 无显著性差异），表明它不是肝细胞疾病的标志物。胆汁淤积患者与非胆汁淤积性肝病对照组的血浆内肽酶24.11活性缺乏重叠，提示该酶活性是胆汁淤积的一个有用生化标志物。此外，由于内肽酶24.11可代谢的肽类范围广泛，血浆内肽酶24.11活性增加可能有助于胆汁淤积综合征的病理生理学过程。
