Park H S, Lee Y L, Kwon H Y, Chey W Y, Park H J
Department of Physiology, College of Medicine, Hallym University, Chunchon, Korea.
Am J Physiol. 1998 Feb;274(2):G413-8. doi: 10.1152/ajpgi.1998.274.2.G413.
Effects of intrapancreatic cholinergic activation by electrical field stimulation (EFS) on secretin-stimulated pancreatic exocrine secretion were investigated in the totally isolated perfused rat pancreas. EFS at 15 V, 2 ms, and 8 Hz for 45 min markedly increased spontaneous pancreatic secretion. This increase was completely inhibited by tetrodotoxin (1 microM) but not by hexamethonium (100 microM). Atropine (2 microM) significantly reduced the EFS-evoked volume flow and amylase output by 52% and 80%, respectively. EFS further increased the secretin (12 pM)-stimulated pancreatic secretion of fluid and amylase. The increases of the two parameters were significantly suppressed by atropine by 28% and 72%, respectively. Interestingly, EFS significantly increased concentrations of somatostatin-like immunoreactivity in portal venous effluents. When pertussis toxin (200 ng/ml) or rabbit antisomatostatin serum (0.1 ml/10 ml; titer of 1:50,000) was intra-arterially administered, EFS further increased the secretin-stimulated pancreatic secretion. In conclusion, the activation of intrapancreatic cholinergic neurons potentiated the secretin action on pancreatic exocrine secretion in the rat. This potentiating effect was significantly reduced by local somatostatin released during EFS that activated intrapancreatic cholinergic tone.
在完全分离灌注的大鼠胰腺中，研究了电场刺激（EFS）激活胰腺内胆碱能对促胰液素刺激的胰腺外分泌的影响。15V、2ms、8Hz的EFS持续45分钟可显著增加胰腺自发分泌。这种增加被河豚毒素（1μM）完全抑制，但未被六甲铵（100μM）抑制。阿托品（2μM）可使EFS诱发的体积流量和淀粉酶分泌量分别显著降低52%和80%。EFS进一步增加了促胰液素（12pM）刺激的胰腺液体和淀粉酶分泌。阿托品分别使这两个参数的增加显著抑制了28%和72%。有趣的是，EFS显著增加了门静脉流出液中生长抑素样免疫反应性的浓度。当动脉内注射百日咳毒素（200ng/ml）或兔抗生长抑素血清（0.1ml/10ml；效价为1:50,000）时，EFS进一步增加了促胰液素刺激的胰腺分泌。总之，胰腺内胆碱能神经元的激活增强了促胰液素对大鼠胰腺外分泌的作用。这种增强作用在EFS期间局部释放的生长抑素激活胰腺内胆碱能张力时显著降低。
