Actions of natural gastric inhibitory peptide on pancreatic acinar cells: due to contamination with cholecystokinin.
Actions of natural gastric inhibitory peptide on pancreatic acinar cells: due to contamination with cholecystokinin.
复制标题
天然胃抑制肽对胰腺腺泡细胞的作用：由于胆囊收缩素的污染。
DOI：
10.1016/0016-5085(82)90117-2
复制
发表时间：
1982
期刊：
影响因子：
29.4
通讯作者：
J. Gardner
中科院分区：
文献类型：
--
作者：
R. Jensen;G. Lemp;M. Beinfeld;J. Gardner
在豚鼠胰腺分散的腺泡中，纯化的天然猪抑胃肽刺激淀粉酶分泌，并增强由促胰液素、血管活性肠肽和8-溴环腺苷5′-单磷酸引起的淀粉酶分泌增加，但不改变由铃蟾肽、卡巴胆碱或缩胆囊素引起的酶分泌增加。胃抑制肽还增加胰腺腺泡中 45Ca 的流出，但不改变细胞环腺苷 5'-单磷酸。这些作用似乎是由于该肽占据胰腺腺泡上的胆囊收缩素受体的能力所致，因为该肽对腺泡细胞功能的影响与其抑制 125 I-胆囊收缩素与胰腺腺泡结合的能力密切相关，并且因为二丁酰环鸟苷 5'-单磷酸（一种特异性胆囊收缩素受体拮抗剂）消除了胃抑制肽引起的酶分泌刺激。此外，抑胃肽和胆囊收缩素抑制 125 I-胆囊收缩素与腺泡细胞受体结合的相对效力与其抑制 125 I-胆囊收缩素与胆囊收缩素特异性抗血清结合的相对效力相同。最后，天然抑胃肽制剂的色谱分析显示出两个蛋白峰，它们都不具有缩胆囊素样免疫反应性或改变的胰腺腺泡细胞功能，加上与天然缩胆囊素在相同位置洗脱的第三个峰，含有缩胆囊素样免疫反应性，并刺激胰腺腺泡的淀粉酶分泌。这些结果表明天然猪抑胃肽被缩胆囊素污染，并且正是这种污染性缩胆囊素解释了天然抑胃肽改变腺泡细胞功能的能力。
In dispersed acini from guinea pig pancreas, purified natural porcine gastric inhibitory peptide stimulated amylase secretion and potentiated the increase in amylase secretion caused by secretin, vasoactive intestinal peptide, and 8-bromo-cyclic adenosine 5′-monophosphate, but did not alter the increase in enzyme secretion caused by bombesin, carbachol, or cholecystokinin. Gastric inhibitory peptide also increased outflux of45Ca from pancreatic acini but did not alter cellular cyclic adenosine 5′-monophosphate. These effects appeared to result from the ability of the peptide to occupy cholecystokinin receptors on pancreatic acini because the peptide's effects on acinar cell function correlated closely with its ability to inhibit binding of125I-cholecystokinin to pancreatic acini and because dibutyryl cyclic guanosine 5′-monophosphate, a specific cholecystokinin-receptor antagonist, abolished the stimulation of enzyme secretion caused by gastric inhibitory peptide. Moreover, the relative potencies with which gastric inhibitory peptide and cholecystokinin inhibited binding of125I-cholecystokinin to acinar cell receptors were the same as their relative potencies for inhibiting binding of125I-cholecystokinin to cholecystokinin-specific antiserum. Finally, chromatography of the preparation of natural gastric inhibitory peptide revealed two protein peaks, neither of which contained cholecystokininlike immunoreactivity or altered pancreatic acinar cell function, plus a third peak that eluted in the same position as native cholecystokinin, contained cholecystokininlike immunoreactivity, and stimulated amylase secretion from pancreatic acini. These results indicate that natural porcine gastric inhibitory peptide is contaminated by cholecystokinin and that it is this contaminating cholecystokinin that accounts for the ability of natural gastric inhibitory peptide to alter acinar cell function.