Rhodes R A, Tai H H, Chey W Y
Am J Dig Dis. 1976 Oct;21(10):873-9. doi: 10.1007/BF01072080.
The endogenous release of secretin in healthy human subjects was studied by measuring plasma secretin levels by radioimmunoassay (RIA) before, during, and following duodenal acidification and eating a meal. The sensitivity of our RIA was assessed by measuring plasma secretin levels during constant intravenous infusions of 4 graded doses of secretin. Our RIA detected significant increases (P less than 0.001) in plasma secretin with each dose, including a low dose of 0.125 U (41.3 ng)/kg hr. Intraduodenal infusion of 0.1 N HCl resulted in marked increases (P less than 0.001) in plasma secretin levels whenever pH in the second portion of the duodenum was reduced to less than 3.5. In contrast, following a meal, pH in the second portion of the duodenum remained consistently greater than 4.5 and plasma secretin levels showed no changes from basal levels. These studies confirm that endogenous release of secretin depends on an acidic pH of the duodenum, and insigificant changes in the plasma secretin level following ingestion of a meal suggest that endogenous release of secretin in the postprandial period is probably to small in quantity to be detected by the present radioimmunoassay method.
通过放射免疫分析法（RIA）在十二指肠酸化前、酸化期间及酸化后，以及进餐前、进餐期间和进餐后测量血浆促胰液素水平，对健康人体受试者促胰液素的内源性释放进行了研究。通过在持续静脉输注4个梯度剂量的促胰液素期间测量血浆促胰液素水平，评估了我们的放射免疫分析法的灵敏度。我们的放射免疫分析法检测到，随着每个剂量的增加，血浆促胰液素均显著升高（P<0.001），包括低剂量0.125 U（41.3 ng）/kg·小时。每当十二指肠第二段的pH值降至低于3.5时，十二指肠内注入0.1 N HCl会导致血浆促胰液素水平显著升高（P<0.001）。相比之下，进餐后，十二指肠第二段的pH值始终保持在大于4.5，血浆促胰液素水平与基础水平相比无变化。这些研究证实，促胰液素的内源性释放取决于十二指肠的酸性pH值，而进餐摄入后血浆促胰液素水平变化不显著表明，餐后促胰液素的内源性释放量可能太小，无法通过目前的放射免疫分析方法检测到。
