The effect of stimulation of extrinsic nerves on peristalsis and on the release of 5‐hydroxytryptamine in the large intestine of the guinea‐pig and of the rabbit

Abstract

Since the classical work by Trendelenburg (1917), many studies have been published on the peristaltic activity of the small intestine (for references see Builbring & Lin, 1958). In a recent investigation Biilbring & Lin (1958) found that small amounts of 5-hydroxytryptamine (5-HT) were continuously released into the lumen of an isolated loop of ileum and that 5-HT, if applied intraluminally, stimulated peristalsis by its action on sensory receptors deeply seated in the intestinal mucosa. These findings have been extended by experiments on small intestine in situ (Bulbring & Crema, 1958, 1959a, but little is known about the effect of 5-HT on, and the release of 5-HT from, the large intestine. Moreover it is not known whether the release of 5-HT from the intestine is controlled by the extrinsic nerves. Bayliss & Starling (1900) have described the movements of the large intestine in situ and the effects of stimulating its sympathetic and parasympathetic nerve supply. Since the distal colon can be excised with both the lumbar sympathetic outflow and the pelvic nerve attached (Garry & Gillespie, 1954, 1955, it seemed of interest to study the action of 5-HT on the peristalsis of the isolated colon and to investigate the effect of extrinsic nerve stimulation on 5-HT release.The effects of atropine, of hexamethonium and of nicotine on the peristaltic reflex as well as on the extrinsic nerve stimulation were also investigated, in the hope of throwing some light on the relationship between the nervous pathways of the peristaltic reflex arc and those of the extrinsic innervation.A preliminary account of some of the results has been given in a communication to the Physiological Society (Lee, 1959).

Role of α2‐adrenoceptors in the sympathetic inhibition of motility reflexes of guinea‐pig ileum

“…There is some evidence that this may be via an effect on a 2 -adrenoceptors (Mizutani et al 1990). Studies of the responses of the guinea-pig small intestine to sustained liquid distensions also indicate that MN stimulation inhibits propulsive contractions of the circular muscle (Lee, 1960;Kreulen et al 1983). This idea is supported by a recent study of the distal colon, which concluded that sympathetic nerves inhibit interneurons that carry reflex activity along the intestine (Spencer et al 1999a).…”

Neurogenic and myogenic motor patterns of rabbit proximal, mid, and distal colon

“…8), indicating that they are propulsive. Interestingly, although these contractions were found to be dependent on enteric neural circuits [as they were TTX-sensitive (29)], to our surprise fast nicotinic transmission was not required, since hexamethonium did not inhibit them nor their change their speed of propagation (27,29). Also, mecamylamine (100 M) failed to block the antegrade or retrograde peristaltic contractions, suggesting that the nicotinic transmission is unlikely to be involved in these peristaltic contractions.…”

An improved method for studying the peristaltic reflex in the isolated colon

“…In the colon, propulsive activity was investigated in situ by Bayliss & Starling (1900), Elliott & Barclay-Smith (1904), Raiford & Mulinos (1934a, b), Auer & Krueger (1947), Bozler (1949b), Hukuhara & Miyake (1959) and in the isolated organ by Langley & Magnus (1905), Tyrode (1910), Currie & Henderson (1926), Lembeck (1958), Lee (1960), Hulkuhara, Nakayama & Nanba (1961), Hukuhara & Neya (1968), and MacKenna & McKirdy (1969).…”