Abstract
In isolated guinea-pig intestine 5-hydroxytryptamine increased the longitudinal muscle contractions in response to acetylcholine while the ganglionic action of nicotine was first facilitated and then blocked. Phenyldiguanide, veratrine, veratridine and protoveratrine, like 5-hydroxytryptamine, depressed the response to nicotine, leaving that to acetylcholine unaffected.
The sensory stimulants, like 5-hydroxytryptamine, facilitated the peristaltic reflex when applied to the mucosa, and abolished it when applied to the serosa. Preceding the block, the initial effect of low concentrations of 5-hydroxytryptamine applied to the serosa was a short stimulation of peristalsis.
Concentrations of 5-hydroxytryptamine which had an approximately equal stimulant action (mucosal 1 to 4 × 10-6, serosal 2 to 8 × 10-8) were tested when various parts of the reflex arc were blocked. During block by procaine introduced into the lumen, mucosal application of 5-hydroxytryptamine re-established peristalsis, but serosal application of 5-hydroxytryptamine had no effect. During block by hexamethonium or atropine present in the bath, 5-hydroxytryptamine restored peristalsis more effectively by serosal application than by mucosal application. During block by serosal application of 5-hydroxytryptamine, morphine, phenoxybenzamine or dihydroergotamine, mucosal application of 5-hydroxytryptamine restored the peristaltic reflex while serosal application had no effect. During block by 2-bromo-lysergic acid diethylamide or lysergic acid diethylamide acting from the serosal surface, 5-hydroxytryptamine had no effect whether acting on the mucosal or on the serosal surface.
It is concluded that 5-hydroxytryptamine facilitates the peristaltic reflex at two sites: when introduced into the lumen it stimulates mucosal sensory receptors; when acting from the serosal surface it sensitizes the muscle to the transmitter acetylcholine. There is also a transient stimulant action on the ganglia which is soon followed by inhibition; this indicates that 5-hydroxytryptamine applied to the serosa abolishes peristalsis by ganglion block.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BELESLIN D., VARAGIC V. The effect of cooling and of 5-hydroxytryptamine on the peristaltic reflex of the isolated guinea-pig ileum. Br J Pharmacol Chemother. 1958 Sep;13(3):266–270. doi: 10.1111/j.1476-5381.1958.tb00901.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BULBRING E., LIN R. C. The effect of intraluminal application of 5-hydroxytryptamine and 5-hydroxytryptophan on peristalsis; the local production of 5-HT and its release in relation to intraluminal pressure and propulsive activity. J Physiol. 1958 Mar 11;140(3):381–407. [PMC free article] [PubMed] [Google Scholar]
- DAWES G. S., COMROE J. H., Jr Chemoreflexes from the heart and lungs. Physiol Rev. 1954 Apr;34(2):167–201. doi: 10.1152/physrev.1954.34.2.167. [DOI] [PubMed] [Google Scholar]
- GADDUM J. H., PICARELLI Z. P. Two kinds of tryptamine receptor. Br J Pharmacol Chemother. 1957 Sep;12(3):323–328. doi: 10.1111/j.1476-5381.1957.tb00142.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GINZEL K. H. The action of lysergic acid diethylamide (LSD 25), its 2-brom derivative (BOL 148) and of 5-hydroxytryptamine (5-HT) on the peristaltic reflex of the guinea-pig ileum. J Physiol. 1957 Jul 11;137(2):62P–623. [PubMed] [Google Scholar]
- IGGO A. Gastro-intestinal tension receptors with unmyelinated afferent fibres in the vagus of the cat. Q J Exp Physiol Cogn Med Sci. 1957 Jan;42(1):130–143. doi: 10.1113/expphysiol.1957.sp001228. [DOI] [PubMed] [Google Scholar]
- LEMBECK F. Die Beeinflussung der Darmmotilität durch Hydroxytryptamin. Pflugers Arch. 1958;265(6):567–574. doi: 10.1007/BF00416582. [DOI] [PubMed] [Google Scholar]
- MARRAZZI A. S. Some indications of cerebral humoral mechanisms. Science. 1953 Oct 2;118(3066):367–370. doi: 10.1126/science.118.3066.367. [DOI] [PubMed] [Google Scholar]
- PAINTAL A. S. The response of gastric stretch receptors and certain other abdominal and thoracic vagal receptors to some drugs. J Physiol. 1954 Nov 29;126(2):271–285. doi: 10.1113/jphysiol.1954.sp005208. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCHAUMANN W. The paralysing action of morphine on the guinea-pig ileum. Br J Pharmacol Chemother. 1955 Dec;10(4):456–461. doi: 10.1111/j.1476-5381.1955.tb00105.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WILLAMS E. M. V., STREETEN D. H. P. The action of morphine, pethidine, and amidone upon the intestinal motility of conscious dogs. Br J Pharmacol Chemother. 1950 Dec;5(4):584–603. doi: 10.1111/j.1476-5381.1950.tb00609.x. [DOI] [PMC free article] [PubMed] [Google Scholar]