Nylander A G, Chen D, Ding X Q, Norlén P, Håkanson R
Department of Pharmacology, University of Lund, Sweden.
Pharmacol Toxicol. 1997 Mar;80(3):142-6. doi: 10.1111/j.1600-0773.1997.tb00387.x.
Cholecystokinin (CCK) stimulates pancreatic enzyme secretion and growth. This study establishes the dose/plasma concentration--and time--response relationships for the trophic effect of CCK on the rat pancreas and evaluates the importance of vagal innervation and muscarinic receptors for the trophic effect. Rats received sulfated CCK-8 (CCK-8s) by continuous subcutaneous infusion. Different doses and different times of treatment were tested. The trophic effect was determined as wet weight and DNA content of the pancreas. The pancreatic weight and DNA content were found to depend not only on the plasma concentration of CCK-8s but also on the duration of treatment. The EC50 value was 40 pmoles CCK-8s per liter. This value should be compared with plasma CCK-8s concentrations of 2-4 pmol/l in intact fed rats. Maximum trophic effect was observed after 7-14 days of infusion. We conclude that although physiologically relevant concentrations of CCK-8s may be important for the maintenance of the pancreas they do not induce growth. In another experiment atropinized, vagally denervated and intact rats were treated with a maximally effective dose of CCK for four days. The trophic effect of CCK-8s was unaffected by vagotomy or atropinization.
胆囊收缩素（CCK）可刺激胰腺酶的分泌和生长。本研究确定了CCK对大鼠胰腺营养作用的剂量/血浆浓度及时间反应关系，并评估了迷走神经支配和毒蕈碱受体对营养作用的重要性。大鼠通过连续皮下输注接受硫酸化CCK-8（CCK-8s）。测试了不同剂量和不同治疗时间。营养作用通过胰腺的湿重和DNA含量来确定。发现胰腺重量和DNA含量不仅取决于CCK-8s的血浆浓度，还取决于治疗持续时间。半数有效浓度（EC50）值为每升40皮摩尔CCK-8s。该值应与正常进食大鼠血浆中2-4皮摩尔/升的CCK-8s浓度进行比较。输注7-14天后观察到最大营养作用。我们得出结论，虽然生理相关浓度的CCK-8s对胰腺的维持可能很重要，但它们不会诱导生长。在另一项实验中，对阿托品化、迷走神经切断和完整的大鼠用最大有效剂量的CCK治疗四天。CCK-8s的营养作用不受迷走神经切断或阿托品化的影响。
