Stewart J J
Pharmacology. 1984;29(1):47-55. doi: 10.1159/000137991.
Rat intestinal transit was determined 30, 60, 150 and 270 min after morphine sulfate or saline given either subcutaneously (s.c.), intraduodenally (i.d.) or intracerebroventricularly (i.c.v.). In addition, two popular methods of quantifying the progression of a radioactive marker along the bowel, the intercept and geometric center methods, were compared. Morphine (5 mg/kg) given s.c. and i.d. produced two distinct periods of reduced intestinal transit, an early phase at 30 min and a late phase at 150 min. Neither phase of the response was influenced by transection of the vagus nerve. The late phase was not affected by cannulation of the bile duct but was completely extinguished when animals were treated with saline instead of the ricinoleic acid, a cathartic agent used in the original experimental protocol. Given i.c.v., morphine (30 micrograms, total dose) inhibited intestinal transit 30 and 60 min after administration. The results indicate that the temporal effects of morphine on rat intestinal transit differ after central and peripheral administration, and in animals treated and not treated with a cathartic agent. Both methods of calculating intestinal transit produced similar statistical results.
在皮下注射（s.c.）、十二指肠内注射（i.d.）或脑室内注射（i.c.v.）硫酸吗啡或生理盐水后30、60、150和270分钟测定大鼠肠道转运情况。此外，还比较了两种常用的量化放射性标记物在肠道中移动进程的方法，即截距法和几何中心法。皮下注射和十二指肠内注射吗啡（5毫克/千克）产生了两个不同的肠道转运减慢期，一个是30分钟时的早期阶段，另一个是150分钟时的晚期阶段。迷走神经切断术对这两个反应阶段均无影响。晚期阶段不受胆管插管的影响，但当动物用生理盐水而非蓖麻油酸（原始实验方案中使用的一种泻药）处理时，该阶段完全消失。脑室内注射吗啡（总剂量30微克）在给药后30和60分钟抑制肠道转运。结果表明，吗啡对大鼠肠道转运的时间效应在中枢和外周给药后以及在使用和未使用泻药处理的动物中有所不同。两种计算肠道转运的方法产生了相似的统计结果。
