Bardram L, Hilsted L, Rehfeld J F
University Department of Surgical Gastroenterology, Rigshospitalet, Copenhagen, Denmark.
Proc Natl Acad Sci U S A. 1990 Jan;87(1):298-302. doi: 10.1073/pnas.87.1.298.
Expression and processing of progastrin were examined in fetal, neonatal, and adult pancreatic tissue from five mammalian species (cat, dog, man, pig, and rat). A library of sensitive, sequence-specific immunoassays for progastrin and its products was used to monitor extractions and chromatography before and after cleavage with processing-like enzymes. The results showed that progastrin and its products are expressed in the pancreas of all species in total concentrations varying from 0.3 to 58.9 pmol/g of tissue (medians). The degree of processing was age- and species-dependent. In comparison with adult pancreatic tissue the fetal or neonatal pancreas processed a higher fraction to bioactive, C-terminally amidated gastrin. Nevertheless, the pancreatic processing was always less complete than that of the adult antral mucosa. The moderate level of expression and the attenuated processing in the adult pancreas contribute to explain previous failures to detect gastrin in normal pancreatic tissue. Our results indicate that gastrin-producing tumors in the pancreas are not ectopic, but arise from cells that normally express the gastrin gene.
在来自五个哺乳动物物种（猫、狗、人、猪和大鼠）的胎儿、新生儿和成年胰腺组织中，对前胃泌素的表达和加工过程进行了研究。使用了一组针对前胃泌素及其产物的灵敏、序列特异性免疫测定法，来监测在类似加工酶切割前后的提取物和色谱情况。结果显示，前胃泌素及其产物在所有物种的胰腺中均有表达，总浓度在0.3至58.9 pmol/g组织（中位数）之间变化。加工程度取决于年龄和物种。与成年胰腺组织相比，胎儿或新生儿胰腺将更高比例的前胃泌素加工成具有生物活性的、C末端酰胺化的胃泌素。然而，胰腺的加工过程始终不如成年胃窦黏膜的加工过程完整。成年胰腺中适度的表达水平和减弱的加工过程，有助于解释先前在正常胰腺组织中未能检测到胃泌素的原因。我们的结果表明，胰腺中产生胃泌素的肿瘤并非异位性的，而是源自正常表达胃泌素基因的细胞。
