Nakagawa A, Stagner J I, Samols E
Department of Medicine, University of Louisville, Kentucky.
Gastroenterology. 1993 Sep;105(3):868-75. doi: 10.1016/0016-5085(93)90907-t.
The stimulating effects of insulin on the exocrine pancreas are well known. The effects of other islet hormones, however, are controversial. The aim of the present study was to determine whether the islet-acinar axis, as a whole, is stimulatory or inhibitory. Because we have shown that retrograde perfusion reverses the islet-acinar directed microcirculation, retrograde perfusion was expected to remove the overall effects of islet hormones from the acinar tissue.
Rat pancreata were perfused (7 mmol/L glucose plus 3 mmol/L mixed amino acids) either anterogradely or retrogradely. Pancreatic juice flow, protein output, and amylase output were measured.
When perfusion was switched from anterograde to retrograde, juice flow increased threefold without changes in protein and amylase output. When cerulein (10(-10) mol/L) was infused, retrograde protein and amylase responses were larger than anterograde responses (each, n = 7; 2.71 +/- 0.23 vs. 1.71 +/- 0.11 mg/40 minutes; 173 +/- 17 vs. 98 +/- 8 U/40 minutes; mean +/- SE; both, P < 0.01). Somatostatin-14 and rat pancreatic polypeptide (each, 10(-9) mol/L) reduced the retrograde protein and amylase responses, but not juice flow, to the anterograde response levels. Conversely, these peptides did not affect exocrine function during anterograde perfusion.
A suppressive role of the islet-acinar axis via endogenous somatostatin and/or pancreatic polypeptide is suggested.
胰岛素对外分泌胰腺的刺激作用已广为人知。然而，其他胰岛激素的作用却存在争议。本研究的目的是确定胰岛 - 腺泡轴整体上是起刺激作用还是抑制作用。因为我们已经表明逆行灌注可逆转胰岛 - 腺泡方向的微循环，所以预期逆行灌注可消除腺泡组织中胰岛激素的总体影响。
对大鼠胰腺进行顺行或逆行灌注（7 mmol/L葡萄糖加3 mmol/L混合氨基酸）。测量胰液流量、蛋白质输出量和淀粉酶输出量。
当灌注从顺行转为逆行时，胰液流量增加了两倍，而蛋白质和淀粉酶输出量没有变化。当注入蛙皮素（10⁻¹⁰ mol/L）时，逆行时蛋白质和淀粉酶的反应大于顺行反应（每组n = 7；分别为2.71±0.23对1.71±0.11 mg/40分钟；173±17对98±8 U/40分钟；平均值±标准误；两者，P < 0.01）。生长抑素 - 14和大鼠胰多肽（均为10⁻⁹ mol/L）将逆行时蛋白质和淀粉酶的反应降低至顺行反应水平，但不影响胰液流量。相反，这些肽在顺行灌注期间不影响外分泌功能。
提示内源性生长抑素和/或胰多肽在胰岛 - 腺泡轴中起抑制作用。
