Upp J R, Poston G J, MacLellan D G, Townsend C M, Barranco S C, Thompson J C
Department of Surgery, University of Texas Medical Branch, Galveston 77550.
Pancreas. 1988;3(2):193-8. doi: 10.1097/00006676-198804000-00014.
Bombesin has both direct and indirect effects [mediated through release of cholecystokinin (CCK)] on pancreatic secretion. Polyamine biosynthesis, essential for DNA synthesis, is increased in the pancreas after CCK stimulation. The purpose of this study was to examine the trophic effects of bombesin and to determine whether the mechanism of bombesin-induced pancreatic growth is mediated through synthesis of polyamines. The time course of bombesin-stimulated polyamine biosynthesis was defined. Rats were studied in groups of six and received intraperitoneal (i.p.) injections every 8 h of either saline, bombesin (10 micrograms/kg), CR1409 (2.5 mg/kg) (a CCK-receptor antagonist), or both to define the effects on pancreatic growth and polyamine biosynthesis. Rats were killed at 14 days and the pancreas was excised, weighed, and analyzed for protein, RNA, and DNA content. We found that bombesin produced significant pancreatic hyperplasia (increased pancreatic weight, protein, and DNA content) after 14 days. CR1409 inhibited only bombesin-stimulated DNA content. Bombesin stimulated polyamine biosynthesis as early as 2 h after administration of bombesin, but CR1409 had no effect. The trophic actions of bombesin are both direct and indirect (mediated through CCK), and the direct effects of bombesin are mediated by polyamine biosynthesis.
蛙皮素对胰腺分泌有直接和间接作用[通过胆囊收缩素（CCK）的释放介导]。多胺生物合成是DNA合成所必需的，在CCK刺激后胰腺中多胺生物合成增加。本研究的目的是研究蛙皮素的营养作用，并确定蛙皮素诱导胰腺生长的机制是否通过多胺合成介导。确定了蛙皮素刺激多胺生物合成的时间进程。将大鼠分成每组6只的小组，每8小时腹腔内（i.p.）注射生理盐水、蛙皮素（10微克/千克）、CR1409（2.5毫克/千克）（一种CCK受体拮抗剂）或两者，以确定对胰腺生长和多胺生物合成的影响。14天后处死大鼠，切除胰腺，称重，并分析蛋白质、RNA和DNA含量。我们发现，14天后蛙皮素导致显著的胰腺增生（胰腺重量、蛋白质和DNA含量增加）。CR1409仅抑制蛙皮素刺激的DNA含量。蛙皮素在给药后2小时就刺激多胺生物合成，但CR1409没有作用。蛙皮素的营养作用既有直接的也有间接的（通过CCK介导），蛙皮素的直接作用由多胺生物合成介导。
