Garry D J, Garry M G, Williams J A, Mahoney W C, Sorenson R L
Department of Cell Biology and Neuroanatomy, University of Minnesota Medical School, Minneapolis 55455.
Am J Physiol. 1989 May;256(5 Pt 1):G897-904. doi: 10.1152/ajpgi.1989.256.5.G897.
The interaction of insulin and somatostatin on amylase secretion was examined in the isolated perfused rat pancreas. Exogenous insulin (10 mU/ml) significantly potentiated cholecystokinin- (CCK; 0.5 mU/ml) stimulated amylase secretion (12.47 +/- 2.9 micrograms/ml, n = 7). Glucose (16.7 mM) stimulated endogenous insulin secretion (523 +/- 66 microU/ml) and also significantly enhanced CCK-stimulated amylase secretion (13.41 +/- 2.8 micrograms/ml, n = 11). When somatostatin was included in the perfusion media, containing insulin and CCK, amylase secretion was reduced to 3.17 +/- 0.83 micrograms/ml (n = 7), a level comparable to that of CCK-stimulated amylase secretion alone. Similarly, addition of exogenous somatostatin to perfusion media, containing 16.7 mM glucose and CCK, reduced amylase secretion to 4.29 +/- 1.09 micrograms/ml (n = 9). The effect of somatostatin and insulin on carbamylcholine-stimulated amylase secretion was also examined. Exogenous insulin (50 mU/ml) potentiated carbamylcholine- (10(-8) M) stimulated amylase secretion, and addition of exogenous somatostatin to the media containing both insulin and carbamylcholine suppressed the insulin potentiation. Uptake of 125I-[Tyr11]somatostatin in the perfused pancreas was saturable as it decreased significantly with the addition of excess unlabeled somatostatin. Autoradiograms revealed uptake of the ligand by both the endocrine islets and the exocrine pancreas with the highest density of grains observed over the acini. These results support the hypothesis that islet peptides modulate the exocrine pancreas, that somatostatin inhibits amylase secretion by inhibiting the action of insulin, and that somatostatin may act directly on the exocrine pancreas via specific receptors on acinar cells.
在离体灌注大鼠胰腺中研究了胰岛素和生长抑素对淀粉酶分泌的相互作用。外源性胰岛素（10 mU/ml）显著增强胆囊收缩素（CCK；0.5 mU/ml）刺激的淀粉酶分泌（12.47±2.9微克/毫升，n = 7）。葡萄糖（16.7 mM）刺激内源性胰岛素分泌（523±66微单位/毫升），也显著增强CCK刺激的淀粉酶分泌（13.41±2.8微克/毫升，n = 11）。当生长抑素包含在含有胰岛素和CCK的灌注培养基中时，淀粉酶分泌降至3.17±0.83微克/毫升（n = 7），这一水平与单独CCK刺激的淀粉酶分泌水平相当。同样，向含有16.7 mM葡萄糖和CCK的灌注培养基中添加外源性生长抑素，可使淀粉酶分泌降至4.29±1.09微克/毫升（n = 9）。还研究了生长抑素和胰岛素对氨甲酰胆碱刺激的淀粉酶分泌的影响。外源性胰岛素（50 mU/ml）增强氨甲酰胆碱（10⁻⁸ M）刺激的淀粉酶分泌，向含有胰岛素和氨甲酰胆碱的培养基中添加外源性生长抑素可抑制胰岛素的增强作用。灌注胰腺中125I-[酪氨酸¹¹]生长抑素的摄取是可饱和的，因为随着过量未标记生长抑素的添加，摄取量显著降低。放射自显影片显示内分泌胰岛和外分泌胰腺均摄取了该配体，在腺泡上观察到的银粒密度最高。这些结果支持以下假设：胰岛肽调节外分泌胰腺，生长抑素通过抑制胰岛素的作用来抑制淀粉酶分泌，并且生长抑素可能通过腺泡细胞上的特异性受体直接作用于外分泌胰腺。
