King J N, Gerring E L
Department of Surgery & Obstetrics, Royal Veterinary College, North Mymms, Herts, U.K.
J Vet Pharmacol Ther. 1988 Dec;11(4):354-61. doi: 10.1111/j.1365-2885.1988.tb00195.x.
Dopamine was infused intravenously (1, 5 and 10 micrograms/kg/min) for 60 min in three fasted ponies. A dose-dependent increase in heart rate occurred that was rapid in onset and termination at the start and end of the infusions, respectively. Dose-dependent changes in gastric and small intestinal motility were observed. An initial marked inhibition of gastric contraction amplitude was followed by a secondary prolonged period of activity. At the same time the small intestine showed a prolonged period of irregular activity (phase II) and a marked increase in the interval between successive phase IIIs. The left dorsal colon and small colon exhibited variable responses. The normal fasting motility pattern was therefore disrupted by dopamine biphasically, an initial inhibition of the stomach being followed by a period of increased activity in the stomach and small intestine which resembled the postprandial motility pattern. Although the cardiovascular effects of dopamine were transient, the increases in gastrointestinal motility persisted long after the infusion was terminated.
对3匹禁食的小马静脉输注多巴胺（1、5和10微克/千克/分钟），持续60分钟。心率出现剂量依赖性增加，分别在输注开始和结束时起效迅速且终止迅速。观察到胃和小肠蠕动的剂量依赖性变化。最初胃收缩幅度明显受到抑制，随后是继发性的长时间活动期。与此同时，小肠出现长时间的不规则活动期（II期），且连续III期之间的间隔明显增加。左背结肠和小结肠表现出不同的反应。因此，多巴胺双相性地破坏了正常的禁食蠕动模式，最初胃受到抑制，随后胃和小肠出现一段类似于餐后蠕动模式的活动增加期。虽然多巴胺对心血管的影响是短暂的，但在输注终止后很长时间，胃肠蠕动的增加仍持续存在。
