Beta sympathetic inhibitory receptors in the small intestine of the guinea-pig

Wilson, A

doi:10.1111/j.2042-7158.1964.tb07421.x

Cited by 15 publications

(10 citation statements)

References 3 publications

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“…9). The number of experiments was insufficient to determine the relative potencies, but the results agree with the findings of Wilson (1964), namely, that isoprenaline had the highest activity and adrenaline the lowest.…”

Section: Combined Ejffects Of Phenoxybenzamine and Propranololsupporting

confidence: 78%

The effects of adrenaline, noradrenaline and isoprenaline on inhibitory α‐ and β‐adrenoceptors in the longitudinal muscle of the guinea‐pig ileum

Kosterlitz

Lydon

Watt

1970

British J Pharmacology

351

105

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Summary1. Two preparations, a segment of the ileum and the myenteric plexuslongitudinal muscle preparation, have been used for an analysis of the inhibitory effects of adrenaline, noradrenaline and isoprenaline on the contractor responses of the longitudinal muscle to acetylcholine or to electrical, coaxial or field, stimulation. 2. Since the inhibitory effects of adrenaline, noradrenaline and isoprenaline on the acetylcholine-induced contractions were not affected by phenoxybenzamine but were antagonized by propranolol, it is concluded that 3-adrenoceptors are present on the muscle cells. 3. The responses to electrical stimulation were suppressed by adrenaline or noradrenaline but only partly inhibited by isoprenaline. Propranolol antagonized the effect of isoprenaline and, to some extent, that of noradrenaline, but scarcely affected the action of adrenaline. Phenoxybenzamine, on the other hand, antagonized most of the effect of adrenaline and, to some extent, that of noradrenaline; it usually potentiated the effect of isoprenaline. 4. The output of acetylcholine evoked by electrical stimulation was diminished by adrenaline or noradrenaline but was not affected by isoprenaline. The depressant effect on acetylcholine release was antagonized by phenoxybenzamine but not affected by propranolol ; therefore these effects of adrenaline and noradrenaline are mediated by a-adrenoceptors. 5. It may be assumed that a-adrenoceptors in situ are stimulated mainly by circulating adrenaline and possibly noradrenaline and thus cause a prejunctional inhibition at the nerve-smooth muscle junction.

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Section: Combined Ejffects Of Phenoxybenzamine and Propranololsupporting

confidence: 78%

The effects of adrenaline, noradrenaline and isoprenaline on inhibitory α‐ and β‐adrenoceptors in the longitudinal muscle of the guinea‐pig ileum

Kosterlitz

Lydon

Watt

1970

British J Pharmacology

351

105

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“…Wilson [22] found the order of potency of inhibition of the guinea pig proximal small intestine in vitro to be isoprenaline ) nor adrenaline ~ adrenaline » phenylephrine.…”

Section: Discussionmentioning

confidence: 99%

Pharmacology of the Human Fetus: Adrenergic Receptor Function in the Small Intestine

McMurphy¹,

Boréus²

1968

Neonatology

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“…Previously, Wilson (1964) found that catecholamines showed a more pronounced inhibition of histamine than of methacholine in the guineapig ileum. In preliminary experiments, however, we found that catecholamine-induced relaxations were of similar magnitude irrespective of whether the preparation had been contracted by carbachol or by histamine (Kamikawa & Shimo, 1979).…”

Section: Discussionmentioning

confidence: 94%

“…In longitudinal smooth muscles of the guinea-pig ileum, it is well known that catecholamines produce a P-adrenoceptor-mediated relaxation but the twitch inhibitory actions of NA and Adr are almost completely antagonized by ablockers, and only partly by P-blockers, and the Isop-induced maximum twitch inhibition was only about 40% (Munro, 1951;Wilson, 1964;Kosterlitz et al, 1970;Wikberg, 1977;Bauer, 1981). Furthermore, Isop 0.16 pM inhibited the submaximal contraction to ACh by about 84% (Kosterlitz, et al, 1970), and Isop 4 pM relaxed by about 60% the contraction induced by carbachol (3 MM) (Wikberg, 1977).…”

Section: Discussionmentioning

confidence: 99%

Inhibitory Actions of Catecholamines on Electrically Induced Contractions of the Submucous Plexus‐longitudinal Muscularis Mucosae Preparation of the Guinea‐pig Oesophagus

Kamikawa

Shimo

Uchida

1982

British J Pharmacology

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1 The submucous plexus-longitudinal muscularis mucosae preparation of the guinea-pig oesophagus was used to study the actions of catecholamines on the twitch responses to electrical stimulation. 2 When the preparation was stimulated coaxially (0.1 Hz, 0.5 ms, supramaximal voltage), stable twitch-like contractions were obtained. These were abolished by tetrodotoxin (0.1 )M) and atropine (0.1 pM), potentiated by physostigmine (0.1 pM), and were mediated presumably by stimulation of intramural cholinergic nerves. 3 The twitch contractions of the muscularis mucosae were inhibited by catecholamines, in a concentration-dependent manner. The order of potency was isoprenaline> adrenaline> noradrenaline > dopamine.4 The inhibitory actions of noradrenaline (1 1pM) and adrenaline (1 pM) were partly reversed by phentolamine (1 pM) or by propranolol (1 pM), and completely abolished by both antagonists together. The inhibitory effect of dopamine (300 pM) was largely reversed by phentolamine (1 pM), but not by propranolol (1 pM), while the inhibitory action of isoprenaline was competitively antagonized only by propranolol (pA2 of 7.6). 5 The contraction of the muscularis mucosae to exogenously applied acetylcholine (ACh, 20 nM) which was comparable in magnitude with that to electrical stimulation was also inhibited by isoprenaline (0.1 pM), adrenaline (1 pM) and noradrenaline (1 pM), but not by dopamine (300 pAM). In the presence of propranolol (1 pM), noradrenaline, adrenaline and dopamine potentiated the ACh-induced contraction, while the effect of isoprenaline was mainly antagonized. The potentiating effects were antagonized by further treatment with phentolamine (1 pM). 6 Adrenaline, noradrenaline and dopamine but not isoprenaline, produced a weak contraction of the longitudinal muscularis mucosae in the presence of propranolol (3 pM). The contractile responses were completely inhibited by phentolamine (3 pM). Tone in the muscularis mucosae induced by carbachol (3 pM) in the presence of phentolamine (10 piM) was inhibited by catecholamines, in a concentration-dependent manner, an effect that was competitively antagonized by propranolol. 7 In the submucous plexus-longitudinal muscularis mucosae preparation of the guinea-pig oesophagus there are three types of adrenoceptor, inhibitory prejunctional a-adrenoceptors, excitatory postjunctional a-adrenoceptors and inhibitory postjunctional 3-adrenoceptors, and cholinergic neurotransmission is inhibited by catecholamines acting at both prejunctional a-and postjunctional P-adrenoceptors.

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Beta sympathetic inhibitory receptors in the small intestine of the guinea-pig

Cited by 15 publications

References 3 publications

The effects of adrenaline, noradrenaline and isoprenaline on inhibitory α‐ and β‐adrenoceptors in the longitudinal muscle of the guinea‐pig ileum

The effects of adrenaline, noradrenaline and isoprenaline on inhibitory α‐ and β‐adrenoceptors in the longitudinal muscle of the guinea‐pig ileum

Pharmacology of the Human Fetus: Adrenergic Receptor Function in the Small Intestine

Inhibitory Actions of Catecholamines on Electrically Induced Contractions of the Submucous Plexus‐longitudinal Muscularis Mucosae Preparation of the Guinea‐pig Oesophagus

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