Onaga T, Okamoto K, Harada Y, Mineo H, Kato S
Veterinary Physiology, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
Regul Pept. 1997 Oct 31;72(2-3):147-53. doi: 10.1016/s0167-0115(97)01055-0.
The present study evaluates the possible role of the vagus nerves in mediating the stimulatory effect of PACAP-27, PACAP-38 and VIP on the exocrine pancreas, especially on enzyme secretion which is atropine sensitive in sheep. The animals were equipped with two cannulae into the common bile duct, a duodenal cannula, and a ruminal cannula under anesthesia. The bilateral cervical vagus nerves were coiled with a cooling device. In conscious animals, the peptides were infused intravenously for 10 min at 10 pmol kg(-1)min(-1) in phase II of the duodenal migrating motor complexes and the same peptide infusion was repeated in the reversible cooling blockade of the vagus nerves. Increment in fluid secretion was not significantly altered by the vagal blockade in all the peptide infusions, while increment in bicarbonate ion by only PACAP-27 was inhibited by the vagal blockade. Increments in protein and amylase output decreased significantly to 32.0+/-5.0 and 23.2+/-2.6% in PACAP27, and to 26.1+/-7.7 and 20.8+/-6.4% in PACAP-38 in the vagal blockade, but the increments by VIP did not decrease. These results demonstrate that circulating PACAP stimulates pancreatic enzyme secretion via the vagal cholinergic preganglionic neurons in sheep, suggesting the central action of PACAP.
本研究评估了迷走神经在介导垂体腺苷酸环化酶激活肽-27（PACAP-27）、垂体腺苷酸环化酶激活肽-38（PACAP-38）和血管活性肠肽（VIP）对绵羊外分泌胰腺，特别是对阿托品敏感的酶分泌的刺激作用中可能发挥的作用。在麻醉状态下，给动物在胆总管插入两根套管、在十二指肠插入一根套管以及在瘤胃插入一根套管。双侧颈迷走神经用冷却装置缠绕。在清醒动物中，在十二指肠移行性运动复合波的第二阶段，以10 pmol kg⁻¹ min⁻¹的剂量静脉输注这些肽10分钟，并在迷走神经可逆性冷却阻断时重复相同的肽输注。在所有肽输注中，液体分泌的增加并未因迷走神经阻断而显著改变，而仅垂体腺苷酸环化酶激活肽-27引起的碳酸氢根离子增加被迷走神经阻断所抑制。在迷走神经阻断时，垂体腺苷酸环化酶激活肽-27组中蛋白质和淀粉酶输出的增加显著降至32.0±5.0%和23.2±2.6%，垂体腺苷酸环化酶激活肽-38组中分别降至26.1±7.7%和20.8±6.4%，但血管活性肠肽引起的增加并未减少。这些结果表明，循环中的垂体腺苷酸环化酶激活肽通过绵羊迷走神经胆碱能节前神经元刺激胰腺酶分泌，提示垂体腺苷酸环化酶激活肽的中枢作用。
