Braaten J T, Greider M H, McGuigan J E, Mintz D H
Endocrinology. 1976 Sep;99(3):684-91. doi: 10.1210/endo-99-3-684.
The presence and development of immunoreactive gastrin (IRGa) in the fetal and neonatal pancreas and pyloric antrum of the rat were studied. IRGa appeared in both organs at least as early as the 16th day of fetal life. Antral IRGa increased rapidly and continuously in the neonatal period, while pancreatic IRGa concentration increased and was maintained at a relatively constant level from days 5 to 35. Monolayer cell cultures of the neonatal rat pancreas were used to evaluate the role of cyclic AMP mediated release of gastrin. The addition of N6,O2'-dibutyryl cyclic AMP (4 mM) or theophylline (4 mM) to the culture medium induced significant release of gastrin. The stimulation of adenylate cyclase with cholera toxin (10 ng/ml) also resulted in significant gastrin release. Long-term cultures (18-24 days) were shown to release gastrin continuously at a relatively constant rate. The cellular localization of pancreatic gastrin in 7-day-old cultures was performed by immunological techniques, using fluorescein-labeled antibodies to gastrin. The gastrin-containing cells were located at the periphery of most of the endocrine cell clusters. Immunofluorescence techniques for insulin and glucagon also showed that the alpha cells had a similar peripheral distribution, although they were more frequent in number. In contrast, insulin-containing cells were numerous and were present in all areas of the endocrine cell clusters. The studies support the following conclusions: a) Gastrin is present in the rat pancreas, even as early as late fetal life; b) Gastrin-producing cells are present and functionally competent in monolayer cell cultures of the neonatal rat pancreas for prolonged periods of time (24 days); c) Gastrin is released from these cells when intracellular levels of cyclic AMP are increased; d) By immunofluorescence methods, the gastrin-producing cells in pancreatic cell cultures are found to be located at the periphery of the endocrine cell clusters.
对大鼠胎儿及新生期胰腺和幽门窦中免疫反应性胃泌素（IRGa）的存在及发育情况进行了研究。IRGa至少在胎儿期第16天就已在这两个器官中出现。幽门窦IRGa在新生期迅速且持续增加，而胰腺IRGa浓度在第5天至35天期间升高并维持在相对恒定水平。利用新生大鼠胰腺的单层细胞培养来评估环磷酸腺苷介导的胃泌素释放的作用。向培养基中添加N6,O2'-二丁酰环磷酸腺苷（4 mM）或茶碱（4 mM）可诱导胃泌素的显著释放。用霍乱毒素（10 ng/ml）刺激腺苷酸环化酶也会导致胃泌素的显著释放。长期培养（18 - 24天）显示胃泌素以相对恒定的速率持续释放。采用免疫技术，使用荧光素标记的抗胃泌素抗体，对7日龄培养物中的胰腺胃泌素进行细胞定位。含胃泌素的细胞位于大多数内分泌细胞簇的周边。胰岛素和胰高血糖素的免疫荧光技术也显示，α细胞虽数量更多但也有类似的周边分布。相比之下，含胰岛素的细胞数量众多且存在于内分泌细胞簇的所有区域。这些研究支持以下结论：a）胃泌素存在于大鼠胰腺中，甚至早在胎儿晚期就已存在；b）在新生大鼠胰腺的单层细胞培养物中，产生胃泌素的细胞长期存在且功能正常（24天）；c）当细胞内环磷酸腺苷水平升高时，胃泌素从这些细胞中释放；d）通过免疫荧光方法发现，胰腺细胞培养物中产生胃泌素的细胞位于内分泌细胞簇的周边。
