Iovanna J, Giorgi D, Dagorn J C
Unité de Recherches de Pathologie Digestive U 31 INSERM, Marseille, France.
Pancreas. 1987;2(5):578-83. doi: 10.1097/00006676-198709000-00014.
To investigate the origin of nonparallel secretion, pancreatic juice was collected in the anesthetized rat, during infusion of [3H]phenylalanine. In the basal state, the amylase to chymotrypsinogen ratios of activities and of [3H] incorporations were 3.5 and 2.5 times higher than in the homogenate, respectively. Both ratios decreased to the value in the homogenate upon caerulein stimulation (600 ng/kg). Inhibition of protein synthesis by cycloheximide (15 ng/kg) did not alter enzyme secretion ratios, and depressed basal protein output only partly, suggesting similar secretory pathways for basal and stimulated secretion. Finally, when [3H]phenylalanine was given before anesthesia, the amylase to chymotrypsinogen ratio of incorporations was again higher in basal secretion than in homogenate, even when further protein synthesis was blocked by cycloheximide before urethane injection. Hence, basal secretion comes from a pancreatic compartment which is functional, although minor, in the conscious animal, and shows a higher rate of amylase synthesis, compared to chymotrypsinogen, than the rest of the gland. It could consist of a subpopulation of acinar cells.
为研究非平行分泌的起源，在麻醉大鼠输注[³H]苯丙氨酸期间收集胰液。在基础状态下，淀粉酶与糜蛋白酶原的活性比和[³H]掺入比分别比匀浆中的高3.5倍和2.5倍。在蛙皮素刺激（600 ng/kg）后，这两个比值均降至匀浆中的水平。用放线菌酮（15 ng/kg）抑制蛋白质合成并未改变酶分泌比值，且仅部分降低基础蛋白输出，提示基础分泌和刺激分泌具有相似的分泌途径。最后，当在麻醉前给予[³H]苯丙氨酸时，即使在注射乌拉坦前用放线菌酮进一步阻断蛋白质合成，基础分泌中[³H]掺入的淀粉酶与糜蛋白酶原比值仍高于匀浆中的比值。因此，基础分泌来自胰腺的一个在清醒动物中虽功能较弱但仍起作用的部分，与腺泡的其他部分相比，该部分淀粉酶合成速率高于糜蛋白酶原。它可能由腺泡细胞的一个亚群组成。
