Onaga T, Onodera T, Mineo H, Kato S
Department of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, Japan.
Comp Biochem Physiol A Physiol. 1995 May;111(1):51-8. doi: 10.1016/0300-9629(95)98519-m.
The effect of exogenous cholecystokinin-octapeptide (CCK-8) on ruminal contractions and the role of efferent pathways of cholinergic and adrenergic nerves on the effect were studied in sheep. Intravenous infusion of CCK-8 at 11.4 and 45.6 pmol/kg/min significantly inhibited the frequency and amplitude of ruminal contractions in conscious sheep. After bilateral cervical vagotomy, intravenous infusion of CCK-8 at 45.6 mol/kg/min had no detectable effect on amplitude of ruminal contractions induced by electric stimulation to the cervical vagus nerve (1 msec, 20 Hz, 5 mA, for 10 sec at 1-min intervals) in anesthetized sheep. The amplitude of contractile responses of ovine ruminal muscle strips to acetylcholine at 5 x 10(-5) M was not inhibited by CCK-8 applied simultaneously at 1 x 10(-9) M. Intravenous infusion of phentolamine at 53.0 nmol/kg/min, propranolol at 101.4 nmol/kg/min, or their combined infusion did not alter the inhibitory action of CCK-8 at either dose on ruminal contractions in conscious sheep. These results suggest that CCK-8, which does not act on the efferent pathway of cholinergic and adrenergic nerves, may reflexively inhibit reticuloruminal contractions via vagal afferent fibers in sheep.
在绵羊中研究了外源性胆囊收缩素八肽（CCK-8）对瘤胃收缩的影响以及胆碱能和肾上腺素能神经传出通路在该效应中的作用。以11.4和45.6 pmol/kg/min的速度静脉输注CCK-8可显著抑制清醒绵羊瘤胃收缩的频率和幅度。双侧颈迷走神经切断术后，以45.6 mol/kg/min的速度静脉输注CCK-8对麻醉绵羊颈迷走神经电刺激（1毫秒，20赫兹，5毫安，每隔1分钟刺激10秒）诱导的瘤胃收缩幅度没有可检测到的影响。在5×10（-5）M时，绵羊瘤胃肌条对乙酰胆碱的收缩反应幅度不会被同时施加的1×10（-9）M的CCK-8抑制。以53.0 nmol/kg/min的速度静脉输注酚妥拉明、101.4 nmol/kg/min的普萘洛尔或它们的联合输注都不会改变任一剂量的CCK-8对清醒绵羊瘤胃收缩的抑制作用。这些结果表明，CCK-8不作用于胆碱能和肾上腺素能神经的传出通路，可能通过绵羊的迷走传入纤维反射性地抑制网瘤胃收缩。
