The Β‐ADRENOCEPTOR STIMULANT PROPERTIES OF OPC‐2009 ON GUINEA‐PIG ISOLATED TRACHEAL, RIGHT ATRIAL AND LEFT ATRIAL PREPARATIONS

Yabuuchi, Youichi

doi:10.1111/j.1476-5381.1977.tb07543.x

Cited by 71 publications

(38 citation statements)

References 20 publications

(32 reference statements)

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“…It was less than those of procaterol and formoterol. Positive chronotropic effects and the selectivity ratio for isoproterenol and salbutamol in this study were practically com patible with those reported previously (6,16). The maximum positive chronotropic response to TA-2005 was about 80% of that of iso proterenol, and it was larger than those of procaterol and salbutamol.…”

Section: Selectivity For Tracheal Musclesupporting

confidence: 76%

“…Although the reason for this disagreement is not clear, possibilities are as follows: potent activity of TA-2005 on /Q2-adrenoceptor caused a positive chronotropic effect on the right atria which contains a significant popula tion (23%) of 82-adrenoceptors in contrast of the left ventricle (24). Secondly, antagonistic activities of salbutamol (17) and procaterol (6) …”

Section: Selectivity For Tracheal Musclementioning

confidence: 99%

“…In 1967, Lands et al (1,2) proposed a classification of /3-adrenoceptors into two subtypes, (mediating the cardiac stimulation) and 82 (mediating the bronchial and vascular relaxation). Since then, many bronchodilators such as trimetoquinol (3,4), salbutamol (5), procaterol (6) and formoterol …”

mentioning

confidence: 99%

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Tracheal Relaxing Effects and β2-Selectivity of TA-2005, a Newly Developed Bronchodilating Agent, in Isolated Guinea Pig Tissues

Kikkawa¹,

Naito²,

Ikezawa³

1991

Japanese Journal of Pharmacology

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ABSTRACT-Tracheal relaxing effects and /32-selectivity of TA-2005 were investi gated by functional experiments and radioligand binding assay in guinea pigs in com parison with those of other ,Q-agonists, isoproterenol, procaterol, formoterol and sal butamol. The relaxing activity of TA-2005 on histamine-induced contraction in the isolated trachea was most potent among the five agonists, and it was blocked by a 82 selective antagonist (ICI 118,551) but not by a /3,-selective antagonist (bisoprolol). The potency of the relaxing effect was in the order of TA-2005 (pD-, = 9.79) > for moterol > procaterol > isoproterenol > salbutamol. The positive chronotropic effect of TA-2005 was similar to that of isoproterenol; and it was more potent than those of formoterol, procaterol and salbutamol in the isolated atria. The selectivity for tracheal muscle to atria of these agonists were in the order of procaterol > formoterol > TA 2005 > salbutamol >> isoproterenol. A radioligand binding experiment using guinea pig lung and cardiac ventricle as ,82 and 81-adrenoceptor sources, respectively, has also demonstrated that TA-2005 possesses extremely high affinity (IC50 = 1.04 nM) and selectivity (38-fold) to X32-adrenoceptors. By addition of GTP, the competition curve of [1251 ]iodocyanopindolol shifted rightward, indicating the agonist property. These results confirmed that TA-2005 is a highly 82-selective agonist that exerts a po tent tracheal relaxing effect.

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Section: Selectivity For Tracheal Musclesupporting

confidence: 76%

Section: Selectivity For Tracheal Musclementioning

confidence: 99%

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Tracheal Relaxing Effects and β2-Selectivity of TA-2005, a Newly Developed Bronchodilating Agent, in Isolated Guinea Pig Tissues

Kikkawa¹,

Naito²,

Ikezawa³

1991

Japanese Journal of Pharmacology

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“…However, there are several examples in the literature of agonists having selectivity for either the rate or force of cardiac contractions. Salbutamol and soterenol (Farmer, Kennedy, Levy & Marshall, 1970) and OPC-2009 (Yabuuchi, 1977) have been shown to exert preferential chronotropic activity in guinea-pig atria. In contrast, dopamine (Goldberg, 1972), dobutamine (Tuttle & Mills, 1975) and thyronamine (Boissier, Giudicelli, Larno & Advenier, 1973) have been found to exhibit inotropic selectivity.…”

Section: Introductionmentioning

confidence: 99%

Dissociation Constants of Isoprenaline and Orciprenaline and Their Relative Efficacies on Guinea‐pig Isolated Atria Determined by Use of an Irreversible Β‐adrenoceptor Antagonist

Broadley

Nicholson

1981

British J Pharmacology

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I Dissociation constants (KA) of isoprenaline and orciprenaline were determined for the positive inotropic and chronotropic responses of guinea-pig isolated atria. Cumulative dose-response curves to the agonists were constructed before and after incubation with and washout of the irreversible ,3-adrenoceptor antagonist, Ro 03-7894 1-(5-chloracetylaminobenzfuran-2-yl)-2-isopropylaminoethanol). 2 After 20 min washout, the curves were displaced to the right with depression of the maxima. After 3 h washout, there was only depression of the maxima. 3 Dissociation constants were determined by plotting reciprocals of molar concentrations before Ro 03-7894 (1/A) against reciprocals of the equiactive concentrations after Ro 03-7894 (1/A'). KA = (slope -1)/intercept. 4 Isoprenaline had a greater affinity (KA) than orciprenaline on both rate and tension. The affinity for rate and tension was identical for both agonists, indicating that the ,B-adrenoceptors were identical. 5 Isoprenaline and orciprenaline produced identical rate response maxima when compared in the same preparation but the orciprenaline tension maximum was only 92.0 + 0.3% that of isoprenaline. 6 These dose-response curves were replotted as response against -log RA/Rt (fraction of receptors occupied) for each agonist concentration, calculated from the equation RA/Rt = (A)/(KA + (A)).

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“…Firstly, to explore the presence of f2-adrenoceptor subtypes in dog fat cells and to establish the validity of the model. Secondly, to compare in vivo the relative potencies of yohimbine, an O2-antagonist and procaterol, a highly selective f2-agonist (Yabuuchi, 1977;O'Donnell & Wanstall, 1985) with special attention being paid to their side-effects on the cardiovascular system and to various endocrinological and metabolic indices such as plasma glucose, insulin and catecholamines.…”

Section: Introductionmentioning

confidence: 99%

Lipomobilizing effects of procaterol and yohimbine in the conscious dog: comparison of endocrinological, metabolic and cardiovascular effects

Valet¹,

Taouis²,

Tran³

et al. 1989

British J Pharmacology

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provoked an equivalent increase in plasma non-esterified fatty acids (+ 100%). Procaterol, but not yohimbine, induced hyperglycaemia (+ 120%). Plasma insulin was weakly enhanced by yohimbine (+ 120%) as compared to the increase given by procaterol (+ 500%). 4 Both drugs stimulated sympathetic nervous system activity, as indicated by the increased plasma noradrenaline concentration, but only yohimbine increased the plasma adrenaline level. 5 Cardiovascular measurements indicated that procaterol strongly enhances heart rate and transiently decreases mean blood pressure. Yohimbine exhibits a weaker effect on heart rate and slightly increases mean blood pressure. 6 The present work clearly indicates that lipid mobilization is enhanced during fasting in the dog by selective fl2-adrenoceptor stimulation or by Cc2-adrenoceptor blockade. This enhanced lipolytic effect may result either from a direct action of the drugs on the adrenoceptors of fat cells or from an activation of the sympathetic nervous system. Procaterol suffers major limitations since it strongly increases heart rate, immunoreactive insulin and glycaemia. On the other hand, yohimbine induces only minor modifications both in cardiovascular and endocrinological parameters.

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The Β‐ADRENOCEPTOR STIMULANT PROPERTIES OF OPC‐2009 ON GUINEA‐PIG ISOLATED TRACHEAL, RIGHT ATRIAL AND LEFT ATRIAL PREPARATIONS

Abstract: I The f,-adrenoceptor stimulant properties of 5-(1-hydroxy-2-isopropylaminobutyl)-8-hydroxy-

Cited by 71 publications

References 20 publications

Tracheal Relaxing Effects and β2-Selectivity of TA-2005, a Newly Developed Bronchodilating Agent, in Isolated Guinea Pig Tissues

Tracheal Relaxing Effects and β2-Selectivity of TA-2005, a Newly Developed Bronchodilating Agent, in Isolated Guinea Pig Tissues

Dissociation Constants of Isoprenaline and Orciprenaline and Their Relative Efficacies on Guinea‐pig Isolated Atria Determined by Use of an Irreversible Β‐adrenoceptor Antagonist

Lipomobilizing effects of procaterol and yohimbine in the conscious dog: comparison of endocrinological, metabolic and cardiovascular effects

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