Eysselein V E, Maxwell V, Reedy T, Wünsch E, Walsh J H
J Clin Invest. 1984 May;73(5):1284-90. doi: 10.1172/JCI111330.
A newly synthesized human big gastrin (G34) that was prepared according to the revised structure and that contained less than 3% oxidized methionine residues was compared with synthetic human little gastrin (G17) for acid-stimulating activity and clearance in human subjects. Prolonged infusions of each type of gastrin revealed that the time required to approach stable plasma concentrations was much longer for G34 than for G17. The time course of plasma gastrin concentration could be described by one-compartment models with half-lives of 44 min for G34 and 8 min for G17. After rapid intravenous infusion, G34 produced a much larger total acid response than did an equimolar dose of G17, and the responses were directly proportional to the integrated plasma gastrin increments. During the third hour of prolonged intravenous infusions of G34 and G17, the exogenous dosage of G34 required to produce the same blood concentration of gastrin was only one-fourth that of G17. Equivalent blood concentrations of G34 and G17 were associated with similar rates of acid secretion. These results suggest that G34 is more potent than has been thought, that it has an activity similar to that of G17 and that it must not be ignored in estimating total acid-stimulating activity of circulating gastrins. The measurement of total carboxyl-terminal immunoreactive gastrin can produce a good estimate of total acid-stimulating activity.
将按照修订结构制备且氧化甲硫氨酸残基含量低于3%的新合成人 big 胃泌素（G34）与合成人 little 胃泌素（G17）进行比较，观察其在人体中的酸刺激活性和清除情况。对每种胃泌素进行长时间输注发现，G34达到稳定血浆浓度所需的时间比G17长得多。血浆胃泌素浓度的时间进程可用一室模型描述，G34的半衰期为44分钟，G17为8分钟。快速静脉输注后，G34产生的总酸反应比等摩尔剂量的G17大得多，且反应与血浆胃泌素增量积分成正比。在对G34和G17进行长时间静脉输注的第三小时，产生相同胃泌素血浓度所需的G34外源性剂量仅为G17的四分之一。G34和G17的等效血浓度与相似的酸分泌速率相关。这些结果表明，G34比之前认为的更具效力，其活性与G17相似，在评估循环胃泌素的总酸刺激活性时不容忽视。总羧基末端免疫反应性胃泌素的测量可以很好地估计总酸刺激活性。
