PT  - JOURNAL ARTICLE
AU  - T. F. Burks
AU  - J. P. Long
TI  - RELEASE OF INTESTINAL 5-HYDROXYTRYPTAMINE BY MORPHINE AND RELATED AGENTS
DP  - 1967 May 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 267--276
VI  - 156
IP  - 2
4099  - http://jpet.aspetjournals.org/content/156/2/267.short
4100  - http://jpet.aspetjournals.org/content/156/2/267.full
SO  - J Pharmacol Exp Ther1967 May 01; 156
AB  - Release of 5-hydroxytryptamine (5-HT) into the perfused vasculature of isolated dog intestinal segments has been found to occur after intraarterial administration of morphine, meperidine, levorphanol, methadone, nalorphine, codeine or apomorphine. The duration of 5-HT release approximately corresponded with the increased intestinal tone produced. Morphine and codeine were shown to be less potent spasmogens of dog intestine during periods of 5-HT tachyphylaxis than during control periods. Perfusion of isolated dog intestinal segments with calcium iondeficient solutions reversibly decreased intestinal responses to morphine, codeine, levorphanol, 5-HT, nicotine and acetylcholine. Potassium ion deficiency had no significant effects. The in situ intestinal responses to morphine were decreased in reserpine-pretreated dogs. It is suggested that 5-HT participates in dog intestine responses to morphine and related agents. © 1967 by The Williams & Wilkins Company