Vagal control of lower oesophageal sphincter motility in the cat

Gonella, J; Niel, J.P.; Roman, C

doi:10.1113/jphysiol.1977.sp012115

Cited by 48 publications

(24 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the basis of the fluctuation in the amplitude of e.j.ps and i.j.ps observed in the colon and the lower oesophagus of the cat, the existence of crossconnections between the intramural excitatory and inhibitory nerve pathways has been proposed (Gonella & Gardette, 1974;Gonella, Niel & Roman, 1977). Enkephalins may act as neurotransmitters in the rabbit small intestine (Oka, 1980); therefore the enkephalinergic intramural neurones might control impulse traffic passing through either one or other pathway.…”

Section: Action Of Opiates On Junction Potentialsmentioning

confidence: 99%

Effects of Enkephalins and Morphine on Spontaneous Electrical Activity and on Junction Potentials Elicited by Parasympathetic Nerve Stimulation in Cat and Rabbit Colon

Bouvier

Gonella

1982

British J Pharmacology

View full text Add to dashboard Cite

The effects of Leu‐enkephalin, Met‐enkephalin and morphine on excitatory junction potentials (e.j.ps) and inhibitory junction potentials (i.j.ps) elicited by stimulation of efferent parasympathetic nerves were studied in cats and rabbits, anaesthetized and in vitro. Enkephalins (0.008 mg/kg in vivo and 10−6m in vitro) enhanced e.j.p. amplitude in rabbit proximal colon and decreased it in rabbit distal colon and in cat colon. Enkephalins decreased i.j.p. amplitude in all the three models. Morphine (0.2 mg/kg in vivo and 10−6m in vitro) had the same effects as enkephalins on e.j.ps. In contrast, morphine decreased i.j.p. amplitude in rabbit proximal and distal colon and increased it in cat colon. Enkephalins and morphine induced (especially in the cat) spike activity which was potentiated by atropine (0.1 mg/kg in vivo or 10−6m in vitro). All the effects of enkephalins and morphine were antagonized by naloxone (0.2 mg/kg in vivo or 10−6m in vitro). These results suggest that the facilitatory effects of enkephalins and morphine on e.j.ps of rabbit proximal colon are due to the absence of opiate receptors on the excitatory nerve pathway and to a removal of inhibition by blockade of the non‐adrenergic, non‐cholinergic inhibitory pathway. Enkephalinergic intramural neurones may modulate the activation of either excitatory or inhibitory pathways in intramural reflexes.

show abstract

Section: Action Of Opiates On Junction Potentialsmentioning

confidence: 99%

Effects of Enkephalins and Morphine on Spontaneous Electrical Activity and on Junction Potentials Elicited by Parasympathetic Nerve Stimulation in Cat and Rabbit Colon

Bouvier

Gonella

1982

British J Pharmacology

View full text Add to dashboard Cite

show abstract

“…Anaesthesia and surgical procedure were identical to those previously described (Gonella et al 1977). The l.o.s.…”

Section: Methodsmentioning

confidence: 99%

“…The surgical procedure was identical to that described in a previous paper (Gonella et al 1977). Helical strips of circular muscle (with attached longitudinal muscle) of 0*8-1 mm width and 40 mm long were used.…”

Section: Sucrose Gap Experimentsmentioning

confidence: 99%

“…which is abolished by 0022-3751/80/1650-0498 $07.50 © 1980 The Physiological Society J. GONELLA, J. P. NIEL AND C. ROMAN a noradrenergic blockers. In previous papers (Gonella et al 1977(Gonella et al , 1979, it was shown that atropine suppressed l.o.s. excitation evoked by the stimulation of both parasympathetic and sympathetic fibres.…”

Section: Introductionmentioning

confidence: 99%

“…has a double extrinsic innervation (parasympathetic and sympathetic). The parasympathetic innervation is achieved by the vagus nerves and consists of two populations of cholinergic preganglionic nerve fibres (Gonella, Niel & Roman, 1977) connected with excitatory cholinergic intramural neurones and with inhibitory non-cholinergic non-adrenergic (purinergic) neurones respectively. The sympathetic innervation consists of post-ganglionic noradrenergic fibres reaching the l.o.s.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mechanism of the noradrenergic motor control on the lower oesophageal sphincter in the cat.

Gonella¹,

Niel²,

Roman³

1980

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. The release of labelled acetylcholine has been measured on lower oesophageal sphincter (1o.s.) muscular strips previously loaded with tritiated choline.2. This release was greatly increased by noradrenaline 10-5 g/ml. and unaffected by atropine 10-6 g/ml., but it was practically abolished if hemicholinium 5-2 x 10-6 M was added to the incubating bath containing the tritiated choline.3. A radioautographic study of sections of l.o.s. strips loaded with tritiated choline showed that the radioactivity was mainly located in the nervous cells of the enteric plexuses and that the muscular cells were very poorly labelled.4. The increased release of acetylcholine induced by noradrenaline did not occur in a Ca2+-free or in a hypermagnesic Tyrode (12 mM).5. Tetrodotoxin 10-6 g/ml. had no effect on the increased release of acetylcholine induced by noradrenaline. In addition, sucrose gap recordings showed that the depolarizing effect of noradrenaline on l.o.s. muscular strips was unaffected by tetrodotoxin 10-6 g/ml.6. It is concluded that acetylcholine released in the l.o.s. under the action of noradrenaline originated from the synaptic endings of the cholinergic intramural neurones.

show abstract