Werlin S L, Grand R J
Am J Physiol. 1979 Apr;236(4):E446-50. doi: 10.1152/ajpendo.1979.236.4.E446.
Mechanisms and development of secretory function were studied in rat pancreas in vitro. Amylase release from term fetal pancreas was refractory to stimulation by carbamylcholine chloride (carbachol) and cholecystokinin-octapeptide (CCK-OP), but was significantly augmented by calcium ionophore (A23187), DBcAMP, 8-Br-cGMP, and theophylline. The latter agent when combined with either cyclic nucleotide analogue further increased secretory responses. At 1 day and 8 days postnatally, responsiveness to carbachol and CCK-OP had been acquired because amylase secretion stimulated by these agents was brisk and at a level comparable to that found in mature tissue. Increasing extracellular calcium concentrations from 1.23 to 5.28 mM had no effect on basal amylase release in either the fetal or 8-day pancreas. No changes in intracellular cAMP concentrations were found at any age under experimental conditions used. Similarily, in fetal tissue, no changes in cGMP concentrations were found in response to carbachol or A23187. However, at 8 days of age, both agents produced two- to four-fold increases in tissue cGMP levels at 1, 2, and 5 min of incubation. These studies confirm that responsiveness to carbachol and CCK-OP is a maturational process in the pancreas that lags behind the development of intracellular processes involved in stimulus-secretion coupling.
在体外对大鼠胰腺的分泌功能机制及发育进行了研究。足月胎儿胰腺释放淀粉酶对氯化氨甲酰胆碱（卡巴胆碱）和八肽胆囊收缩素（CCK-OP）的刺激无反应，但钙离子载体（A23187）、二丁酰环磷腺苷（DBcAMP）、8-溴环磷鸟苷（8-Br-cGMP）和茶碱可显著增强其释放。后一种药物与任何一种环核苷酸类似物联合使用时，可进一步增强分泌反应。出生后1天和8天，对卡巴胆碱和CCK-OP的反应性已获得，因为这些药物刺激的淀粉酶分泌活跃，且水平与成熟组织中的相当。将细胞外钙浓度从1.23 mM提高到5.28 mM对胎儿或8日龄胰腺的基础淀粉酶释放均无影响。在所使用的实验条件下，任何年龄的细胞内环磷腺苷浓度均未发现变化。同样，在胎儿组织中，对卡巴胆碱或A23187的反应未发现环磷鸟苷浓度有变化。然而，在8日龄时，这两种药物在孵育1、2和5分钟时均使组织中环磷鸟苷水平增加了2至4倍。这些研究证实，对卡巴胆碱和CCK-OP的反应性是胰腺中的一个成熟过程，其落后于刺激-分泌偶联所涉及的细胞内过程的发育。
