Kleveland P M, Waldum H L, Bjerve K S, Fjøsne H E
Scand J Gastroenterol. 1986 Oct;21(8):945-50. doi: 10.3109/00365528608996400.
A bioassay sensitive to gastrin (G 1-17) in physiological concentrations and suitable for testing of biological activity of minor amounts of radioiodinated gastrin is reported. G 1-17 was iodinated by a gentle Iodo-gen method and purified to high specific activity (1900 Ci/mmol). Totally isolated vascularly perfused rat stomachs were prepared and stimulated by graded amounts of G 1-17. Gastrin 'dose'-dependently increased the acid output from 5.7 +/- 1.0 mueq/40 min (basal) to a maximum of 58.8 +/- 10.0 mueq/40 min at a concentration of 520 pmol/l in the vascular perfusate. The lowest G 1-17 concentration that significantly increased the acid output from the basal value was 65 pmol/l, corresponding to a dose of 17.5 ng/stomach-hour. 125I-G 1-17 also increased the acid output significantly at this threshold dose. The amount of lactic acid enzymatically determined in the luminal perfusate was negligible, indicating a true parietal cell stimulation. Accordingly, a very sensitive bioassay for gastrin, suitable for testing of biological activity of G 1-17 and 125I-G, is described. Significant acid responses were obtained with physiological concentrations of gastrin, requiring less than 100 ng of hormone and labelled hormone, respectively, to show biological activity.
报道了一种对生理浓度胃泌素（G 1-17）敏感且适用于检测少量放射性碘标记胃泌素生物活性的生物测定法。G 1-17通过温和的碘甘氨酸法进行碘化，并纯化至高比活性（1900 Ci/mmol）。制备完全分离的血管灌注大鼠胃，并使用不同剂量的G 1-17进行刺激。胃泌素“剂量”依赖性地将酸分泌量从5.7±1.0微当量/40分钟（基础值）增加到血管灌注液中浓度为520 pmol/l时的最大值58.8±10.0微当量/40分钟。能使酸分泌量从基础值显著增加的最低G 1-17浓度为65 pmol/l，相当于17.5 ng/胃-小时的剂量。125I-G 1-17在该阈值剂量下也显著增加了酸分泌量。通过酶法测定的腔内灌注液中乳酸量可忽略不计，表明是真正的壁细胞刺激。因此，描述了一种非常敏感的胃泌素生物测定法，适用于检测G 1-17和125I-G的生物活性。用生理浓度的胃泌素可获得显著的酸反应，分别需要少于100 ng的激素和标记激素来显示生物活性。
