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Harri MN. Temperature-dependent sensitivity of adrenoreceptors in the toad's heart. ACTA PHARMACOLOGICA ET TOXICOLOGICA 2009; 33:273-9. [PMID: 4800673 DOI: 10.1111/j.1600-0773.1973.tb01527.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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On the fundamental difference in the thermodynamics of agonist and antagonist interactions with beta-adrenergic receptors and the mechanism of entropy-driven binding. Biochem Pharmacol 1990; 40:663-9. [PMID: 1974762 DOI: 10.1016/0006-2952(90)90299-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Gurden JM, Apperley GH, Drew GM. A comparison of the properties of prenalterol and corwin at beta 1- and beta 2-adrenoreceptors in vitro. JOURNAL OF AUTONOMIC PHARMACOLOGY 1989; 9:79-91. [PMID: 2565903 DOI: 10.1111/j.1474-8673.1989.tb00199.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. The affinities and efficacies (relative to isoprenaline) of prenalterol and corwin at beta 1- and beta 2-adrenoreceptors, have been determined in isolated cardiac and vascular tissues respectively. 2. Prenalterol and corwin have similar affinities for cardiac beta 1-adrenoreceptors. The affinity of prenalterol for beta 2-adrenoreceptors is approximately 10 times lower than for beta 1-adrenoreceptors; that for corwin is approximately 100 times lower than for beta 1-adrenoreceptors. 3. The efficacies of prenalterol and corwin, relative to isoprenaline, at beta 1 and beta 2-adrenoreceptors, are similar. 4. The greater selectivity of corwin compared with prenalterol, as an agonist at beta 1-adrenoreceptors, is a reflection of its lower affinity for beta 2-adrenoreceptors.
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Affiliation(s)
- J M Gurden
- Department of Cardiovascular Pharmacology, Glaxo Group Research Ltd, Hertfordshire, UK
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Zorbas M, Kennedy RH, Seifen E. Myocardial responsiveness to isoproterenol and calcium: a comparison of SD and F344 rats. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY 1988; 89:333-6. [PMID: 2899008 DOI: 10.1016/0742-8413(88)90233-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. Inotropic effects of isoproterenol and extracellular Ca2+ were compared in left atrial muscle isolated from F344 and SD rats. Preparations from the F344 strain were more sensitive to the actions of both agents. 2. The chronotropic action of isoproterenol was not different in right atria isolated from the two strains. 3. This suggests that the strain-related difference in responsiveness to the inotropic effect of isoproterenol is not caused by heterogeneity in the beta-adrenoceptor/adenylate cyclase system but rather by variations in excitation-contraction coupling.
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Affiliation(s)
- M Zorbas
- Department of Pharmacology and Interdisciplinary Toxicology, University of Arkansas for Medical Sciences, Little Rock 72205
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Hawthorn MH, Chess-Williams RG, Grassby PF, Broadley KJ. The use of forskolin to investigate the site of cardiac beta-adrenoreceptor supersensitivity. JOURNAL OF AUTONOMIC PHARMACOLOGY 1985; 5:231-9. [PMID: 2997230 DOI: 10.1111/j.1474-8673.1985.tb00124.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The positive inotropic responses of left atria and papillary muscles and the positive chronotropic responses of right atria of guinea-pigs to isoprenaline and forskolin were examined. An increase in sensitivity of the three preparations to isoprenaline was observed by lowering the bath temperature from 38 to 30 degrees C as demonstrated by a leftwards shift of the concentration-response curves. A similar degree of supersensitivity was observed for forskolin. Since forskolin is reputed to stimulate adenylate cyclase directly, whereas isoprenaline stimulates via the regulatory nucleotide Ns protein, this would suggest a common site for the supersensitivity at adenylate cyclase. However, the possibility that forskolin also stimulates via the Ns protein in producing cardiac stimulation and that this is the site of hypothermia-induced supersensitivity is discussed. Supersensitivity to isoprenaline was also observed in left atria and papillary muscles from guinea-pigs chronically pretreated with reserpine for 3 days (5 mg/kg at 72 h, 3 mg/kg at 48 and 24 h) or 7 days (0.1 mg/kg daily). In the same tissues, there was no change in the sensitivity to forskolin. The site of the supersensitivity can therefore be concluded to occur before the level of adenylate cyclase activation either directly or via the regulatory Ns protein; possibly at the beta-adrenoreceptor itself.
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Chess-Williams RG, Broadley KJ. Temperature dependence of beta 1-adrenoceptor-mediated responses examined by use of partial agonists. Eur J Pharmacol 1985; 108:25-32. [PMID: 2858394 DOI: 10.1016/0014-2999(85)90279-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The inotropic and chronotropic responses of guinea pig atria, and the relaxation responses of guinea pig intestine, trachea, lung, uterus and vas deferens to catecholamines have been examined at bath temperatures of 38 degrees C and 30 degrees C. Hypothermia resulted in a supersensitivity of cardiac tissues with a decrease in isoprenaline EC50 and an increase in the maximum response to the partial agonist, salbutamol. Ileum responses to isoprenaline were potentiated at 30 degrees C but no partial agonist could be found on this tissue. Responses of the lung and vas deferens to partial agonists were not affected by temperature, while uterine responses were inhibited by hypothermia. The trachea was supersensitive to isoprenaline at 30 degrees C, however this was not due to a change in beta-adrenoceptor sensitivity but an inhibition of COMT. Partial agonist responses of trachea were similar at both temperatures. beta-Adrenoceptor supersensitivity was therefore observed only where responses are mediated primarily by beta 1-adrenoceptors and supports the concept that beta 1- but not beta 2-adrenoceptors exhibit hypothermia-induced supersensitivity.
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Chess-Williams RG, Broadley KJ, Duncan C. A fundamental temperature-dependent difference between beta-adrenoceptor agonists and antagonists. Life Sci 1984; 35:1091-9. [PMID: 6090830 DOI: 10.1016/0024-3205(84)90074-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Positive inotropic and chronotropic responses of guinea-pig isolated left and right atria to sympathomimetic amines were examined at bath temperatures of 38, 30 or 25 degrees C. The concentration-response curves to isoproterenol and orciprenaline were displaced to the left by cooling, indicating hypothermia-induced supersensitivity. The affinities of isoproterenol and orciprenaline were determined as their dissociation constants (pKA) from antagonism of their responses by either the functional antagonist carbachol or Ro 03-7894 which is reported to be an irreversible beta-adrenoceptor antagonist. By both methods of calculation, the affinities of isoproterenol and orciprenaline for the beta-adrenoceptors mediating inotropic and chronotropic responses were increased by lowering the temperature. In contrast, the affinity of practolol, measured as the pA2 for competitive antagonism of the isoproterenol- and orciprenaline-induced inotropic and chronotropic responses, did not increase with cooling. Thus hypothermia-induced supersensitivity is associated with an increase in agonist affinity only, which indicates a fundamental temperature-dependent difference between agonist and antagonist interactions with the beta-adrenoceptor.
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Broadley KJ, Williams RG. Temperature-induced changes in dissociation constants (KA) of agonists at cardiac beta-adrenoceptors determined by use of the irreversible antagonist Ro 03-7894. Br J Pharmacol 1983; 79:517-24. [PMID: 6140043 PMCID: PMC2044879 DOI: 10.1111/j.1476-5381.1983.tb11026.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The positive inotropic responses of guinea-pig left atria and papillary muscles and positive chronotropic responses of right atria to sympathomimetic amines were examined at 38 degrees and 30 degrees C. At the lower temperature, supersensitivity to orciprenaline and isoprenaline was exhibited as shifts of the dose-response curves to the left and significant reductions in EC50 values. This supersensitivity could not be attributed to reduced metabolism since the experiments were performed in the presence of metanephrine (10(-5)M) and U-0521 (3',4'-dihydroxy-2-methylpropiophenone) (10(-4)M) as inhibitors of extraneuronal uptake and catechol-O-methyltransferase (COMT) respectively, and the agonists are not susceptible to neuronal uptake. After incubation of the tissues with Ro 03-7894 (1-(5-chloracetylaminobenzfuran-2-yl)-2-isopropylaminoethanol), followed by its prolonged washout (greater than 2h), the maximum responses to isoprenaline and orciprenaline were depressed, confirming the apparently irreversible beta-adrenoceptor antagonism. Dissociation constants (KA) for isoprenaline and orciprenaline were determined from the equiactive concentrations obtained before (A) and after (A') incubation with Ro 03-7894, plotted as 1/A against 1/A' (KA = (slope-1)/intercept). KA values were the same for orciprenaline in the three cardiac preparations and for isoprenaline in the atria. This applied at 38 degrees and 30 degrees C and indicates that the beta-adrenoceptors mediating the inotropic and chronotropic responses of the guinea-pig heart do not differ. The KA values of both agonists were, however, consistently and significantly lower at 30 degrees than at 38 degrees C, indicating an increase in affinity. 8 It is concluded that hypothermia-induced supersensitivity of cardiac tissue to sympathomimetic amines is associated with an increase in their affinity for the B-adrenoceptors.
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Longhurst PA, McNeill JH. Guinea-pig and rabbit papillary muscles differ in their response to histamine. GENERAL PHARMACOLOGY 1983; 14:239-45. [PMID: 6301930 DOI: 10.1016/0306-3623(83)90003-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Guinea-pig and rabbit papillary muscles differ in their response to histamine. 1. Basal developed force (BDF) and maximal developed force (MDF) following isoproterenol and histamine were determined in rabbit and guinea-pig papillary muscles under a variety of experimental conditions. Hypothermia and an increase in the calcium concentration increased the BDF in both tissues. 2. In the guinea-pig MDF increased to a similar extent following both agonists. In the rabbit the MDF response to histamine was much less than the response to isoproterenol. 3. In the guinea-pig papillary muscle, stimulation of both beta- and H2-receptors produces an increase in cyclic AMP. The rabbit papillary muscle contains H1-receptors, stimulation of which has no effect on cyclic AMP. The reduced MDF effect of histamine compared to isoproterenol in the rabbit may be due to the differing biochemical events following beta- or H1-stimulation.
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Stene-Larsen G. Comparative aspects of cardiac adrenoceptors: characterization of the beta 2-adrenoceptor as a common "adrenaline"-receptor in vertebrate hearts. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C: COMPARATIVE PHARMACOLOGY 1981; 70:1-12. [PMID: 6117399 DOI: 10.1016/0306-4492(81)90071-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Broadley KJ, Nicholson CD. The use of an irreversible beta-adrenoreceptor antagonist to examine reserpine- and hypothermia-induced supersensitivity of guinea-pig atria. JOURNAL OF AUTONOMIC PHARMACOLOGY 1980; 1:27-35. [PMID: 6122688 DOI: 10.1111/j.1474-8673.1980.tb00438.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
1 Positive inotropic and chronotropic responses to guinea-pig isolated left and right atria respectively to the sympathomimetic amine orciprenaline were recorded. 2 Pretreatment of animals with reserpine for 3 days produced supersensitivity of both the inotropic and chronotropic responses. Lowering the bath temperature from 38 degrees to 30 degrees C produced supersensitivity of untreated atria to the inotropic responses only. 3 Irreversible beta-adrenoreceptor antagonism of orciprenaline by Ro 03-7894 was demonstrated by a persistent depression of the maximum inotropic and chronotropic responses after a prolonged washout from the bath (3 h). 4 The depression of the maximum rate and tension responses by Ro 03-7894 was less in atria from reserpine-pretreated animals. 5 The maxima were also depressed less at the lower bath temperature of 30 degrees C. However, when atria were cooled during the incubation with Ro 30-7894, the maxima were still depressed to the 38 degrees C level. 6 That these results suggest either a receptor proliferation or change in efficacy as possible mechanisms for reserpine- and hypothermia-induced supersensitivity is discussed.
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Weiland GA, Minneman KP, Molinoff PB. Fundamental difference between the molecular interactions of agonists and antagonists with the beta-adrenergic receptor. Nature 1979; 281:114-7. [PMID: 38405 DOI: 10.1038/281114a0] [Citation(s) in RCA: 233] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antagonist binding to the beta-adrenergic receptor is largely entropy driven, with only a small enthalpy component. The binding of agonists, on the other hand, is associated with a large decrease in enthalpy which permits a highly unfavourable decrease in entropy. The thermodynamic differences between the binding of agonists and antagonists may provide new insights into the molecular basis for hormone stimulation of adenylate cyclase activity.
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Mori K, Hashimoto H, Hasegawa H, Nakashima M. Influence of temperature on the sensitivity of the adrenoceptors in the isolated atria of guinea pigs and rats. Eur J Pharmacol 1979; 55:189-97. [PMID: 456416 DOI: 10.1016/0014-2999(79)90391-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The influence of the bath temperature on the responsiveness to sympathomimetic amines was studied with isolated guinea pig and rat atria. In electrically driven guinea pig left atria, the dose-response curve for the positive inotropic effect of isoproterenol (ISO) was shifted to the left by lowering the temperature from 36 to 24 degrees C. The positive inotropic effect of phenylephrine (PHE) in lower concentrations was attenuated by lowering the temperature. Phentolamine markedly inhibited the PHE response at 36 and 32 degrees C, whereas it produced no inhibition at 24 degrees C. Similar changes were observed with rat left atria. In guinea pig left atria, propranolol inhibited the response to PHE more effectively at 24 degrees C than 32 degrees C. With guinea pig and rat atria the dose--response curve for the positive inotropic effect of PHE in the presence of phentolamine was shifted to the left by lowering the temperature. The results suggest that lowering the temperature of the bath solution diminished the positive inotropic effect of PHE mediated by alpha-adrenoceptors and potentiated that mediated by beta-adrenoceptors.
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Reinhardt D, Ritter E. Hypothermia-induced potentiation of histamine H2-receptor-mediated relaxation and cyclic AMP increase in the isolated mesenteric artery of the rabbit. AGENTS AND ACTIONS 1979; 9:9-14. [PMID: 223421 DOI: 10.1007/bf02024089] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
On helically cut strips of the rabbit's mesenteric artery, a temperature decrease from 42 degrees C to 25 degrees C reduced the contractile responses to histamine. Metiamide shifted the dose-response curve of the histamine-induced contraction towards higher values at 25 degrees C, but not at 42 degrees C. Furthermore, on arterial strips contracted by phenylephrine histamine evoked a dose-dependent relaxation at 25 degrees C whereas at 42 degrees C only slight relaxing responses to histamine occurred. Metiamide was capable of preventing the relaxation induced by histamine in a competitive manner. At 25 degrees C the relaxation as produced by histamine was accompanied by increases in cyclic AMP which occurred prior to the relaxing effects. Metiamide abolished the cyclic AMP increase in response to histamine. At 42 degrees C histamine was unable to elevate the cyclic AMP content. Thus, it is concluded that a cyclic AMP-mediated relaxation due to stimulation of H2-receptors counteracts the histamine-induced contraction and reduces the contractile responses to histamine at low temperatures. In addition, clear-cut evidence exists from the present study that also on artery smooth muscle the H2-receptor-mediated responses are closely associated to cyclic AMP.
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Tenner TE, McNeill JH, Carrier O. The role of calcium in supersensitivity to the inotropic effects of norepinephrine. Eur J Pharmacol 1978; 50:359-67. [PMID: 699962 DOI: 10.1016/0014-2999(78)90141-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Experiments using electrically stimulated rabbit left atria have demonstrated that supersensitivity to the inotropic effects of norepinephrine can be induced by either chronic reserpine pretreatment or hypothermia (lowering the temperature of the bathing medium). These two experimental conditions for inducing supersensitivity were not additive implying that they shared a common mechanism of action. Norepinephrine had no significant effect on the amplitude of a potentiated contraction of the rabbit atrium when the temperature was reduced from 37 to 30 degrees C or following pretreatment with reserpine (30 or 37 degrees C). Under these same conditions the ED50 of norepinephrine on the normal contraction was reduced. It is concluded that both reserpine pretreatment and hypothermia induce supersensitivity to the inotropic effects of norepinephrine by enhancing the cellular store of activator calcium while not affecting the ability of norepinephrine to release activator calcium.
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Li CK, Mitchelson F. Effect of variations in temperature on antimuscarinic activity in guinea-pig atria. EXPERIENTIA 1978; 34:641-3. [PMID: 658257 DOI: 10.1007/bf01937009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The characteristics of the antimuscarinic activity of homatropine, gallamine and stercuronium in guinea-pig atria remained constant over the temperature range 22--37 degrees C in that a linear Arunlakshana-Schild plot was obtained with homatropine and nonlinear plots occurred with gallamine or stercuronium. A trend towards higher dose-ratios with reduction in temperature was only significant for gallamine.
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Reinhardt D, Butzheinen R, Brodde OE, Schümann HJ. The role of cyclic AMP in temperature-dependent changes of contractile force and sensitivity ot isoprenaline and papaverine in guinea-pig atria. Eur J Pharmacol 1978; 48:107-16. [PMID: 205421 DOI: 10.1016/0014-2999(78)90048-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Right and left guinea-pig atria responded to decreasing temperatures (42-27 degrees C) with elevation for force of contraction and concomitant increases in cAMP. When atria were rapidly cooled from 42 to 27 degrees C the increase in cAMP occurred prior to the onset of the inotropic responses. Papaverine (3 X 10(-5) M) potentiated the effects of temperature on cAMP and force of contraction on left atria driven at 0.5 Hz. On right atria beating spontaneously at frequencies above 2 Hz papaverine only potentiated the effect of decreasing temperatures on the response of cAMP but not on that of force of contraction. Time course studies of the effects of isoprenaline (3 X 10(-8) M) on right atria at 27 degrees C showed large inotropic responses to isoprenaline which were accompanied by increases in cAMP. At 42 degrees C the responses of force of contraction and cAMP to isoprenaline occurred faster and were only short-lasting. As with the time courses for isoprenaline, dose-response curves for the effect of isoprenaline and papaverine on cAMP content and force of contraction also appeared to be shifted towards higher levels at hypothemia. However, pD2 values reflected increases in affinity for inotropic, but not for the cAMP responses to isoprenaline and papaverine at hypothermia. These results show that cyclic AMP is involved in the inotropic responses to hypothermia, but not in the supersensitivity of heart to isoprenaline and papaverine as observed at low temperatures.
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Duncan C, Broadley KJ. The influence of temperature upon reserpine-induced supersensitivity of guinea-pig isolated atria to isoprenaline and salbutamol. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1977; 297:163-70. [PMID: 857168 DOI: 10.1007/bf00499926] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
1. The aim of this investigation was to determine whether supersensitivity of isolated atria to sympathomimetic amines following pretreatment with reserpine was evident at low temperatures, which alone induced supersensitivity. 2. Cumulative dose-response curves for the positive inotropic and chronotropic responses of isolated guinea-pig atria to isoprenaline and the partial agonist salbutamol were plotted as a percentage of the maximum response to isoprenaline. 3. In atria from reserpine-pretreated guinea-pigs set up at 38 degrees C, supersensitivity of both rate and tension responses was observed as a shift of the curves to the left and an increase of the maximum responses to salbutamol. Tension responses were potentiated more than rate responses. At 30 degrees C the supersensitivity became less apparent and at 25 degrees C was virtually absent. 4. The dose-response curves in untreated atria at low temperatures revealed that hypothermia itself produced supersensitivity of rate and tension responses. The dose-response curves were displaced to the left and the salbutamol maxima were raised so that at 25 degrees C it became almost a full agonist. The hypothermia-induced supersensitivity was therefore sufficient to mask any supersensitivity resulting from pretreatment with reserpine. 5. The hypothermia-induced supersensitivity of the rate response was dependent upon the method of plotting. When plotted in absolute units of beats per min no supersensitivity of the rate response was evident. Supersensitivity of the tension response at the lower temperatures and of both rate and tension responses following pretreatment with reserpine were independent of the plotting method.
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Vogel WH, Trendelenburg U. Alpha-and- beta-activity of O-methylated derivatives of norepinephrine and epinephrine. EXPERIENTIA 1977; 33:260-1. [PMID: 844582 DOI: 10.1007/bf02124099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metanephrine, iso-metanephrine, normetanephrine and isonormetaephrine were tested for alpha- and beta-activity on various tissues obtained from rats, guinea-pigs and cats. It was found that methylation of the hydroxyl groups of norepinephrine or epinephrine in either the 3- or 4-position markedly reduces or abolishes alpha- and beta-activity with the exception of the nictitating membrane of the cat. This receptor seems to show a tissue difference.
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Reinhardt D, Roggenbach W, Schmidt U, Schümann HJ. Effect of papaverine on the frequency-force relationship in guinea-pig left atria. Eur J Pharmacol 1977; 41:123-32. [PMID: 832671 DOI: 10.1016/0014-2999(77)90201-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Contractile responses of guinea-pig atria to papaverine were analyzed under different stimulation frequencies. Atria, driven at 2 Hz, showed positive inotropic responses to papaverine which were maximal within 10-15 min. These responses were maintained for 60 min in the presence of low concentrations of papaverine (up to 10(-5) M), but reversed into marked negative inotropic effects under the influence of higher concentrations. The well-known frequency-force relationship was reversed by papaverine. At low stimulation rates papaverine elicited positive inotropic responses, which gradually decreased with increasing frequencies until strong cardiodepression occurred. A frequency-force curve obtained in the presence of both the Ca2+-antagonistic drug D 600 and the inhibitor of the phosphodiesterase theophylline was similar to that obtained under the influence of papaverine. Theophylline alone evoked positive inotropic effects at all frequencies studied and left the character of the ascending staircase unchanged. In contrast, D 600 was ineffective at low, but cardiodepressive at high stimulation frequencies. In the presence of D 600 or papaverine high external Ca2+ could not restore a normal frequency-force relationship. The reversal of the frequency-force relationship as produced by D 600 and papaverine could not be obtained by lowering of the external Ca2+. The present results show that papaverine is able to evoke marked positive inotropic effects at low stimulation frequencies by inhibition of phosphodiesterase. At high frequencies, however, these effects are masked by negative inotropic responses due to the inhibitory action of papaverine on Ca2+-exchange of the cardiac muscle cell.
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Broadley KJ, Duncan C. The contribution of metabolism to the hypothermia-induced supersensitivity of guinea-pig isolated atria; selective supersensitivity for beta-adrenoceptor agonists and their positive inotropic responses. GENERAL PHARMACOLOGY 1977; 8:305-10. [PMID: 23978 DOI: 10.1016/0306-3623(77)90004-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Rosen G, Rauckman EJ. Effect of temperature upon the conformation of acetylcholine receptors. Biochem Pharmacol 1976; 25:1329-32. [PMID: 938555 DOI: 10.1016/0006-2952(76)90098-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Bassett AL, Wiggins JR. The effect of temperature on potassium chloride contracture in cat myocardium. J Physiol 1976; 258:357-75. [PMID: 957161 PMCID: PMC1308980 DOI: 10.1113/jphysiol.1976.sp011424] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
1. Contracture was induced in cat myocardium by exposure to 140 mM-KC1 In isotonic Tyrode solution. Force of contracture expressed as mg/mm2 (muscle cross-sectional area) falls with increasing cross-sectional area. 2. The effect of temperature on isometric force developed during contracture was evaluated both in normal (untreated) atrial and ventricular muscle and following treatment with sympatholytic drugs. 3. The force of contracture was not significantly affected by sympatholytic drugs at 36 degrees C. 4. In normal atrial and ventricular muscle, force of contracture decreased when the muscle was cooled from 36 to either 29 or 20 degrees C. 5. In atrial muscle, the effect of temperature was not changed by sympatholytic drugs. In contrast, exposure to sympatholytic drugs increased contracture force developed by ventricular muscle at 20 degrees C. Also, contracture force was significantly greater at 20 than at 36 degrees C in ventricular muscle from reserpine-pretreated cats. 6. It is suggested that ventricular muscle becomes more sensitive to the relaxing effects of endogenous catecholamines at temperature is lowered. 7. The differences shown between atrial and ventricular muscle with respect to the effect of temperature and sympatholytic drugs on contracture force may result from the differing amounts of sarcoplasmic reticulum found in these types of cardiac muscle and also from different mechanisms of "excitation-contracture" coupling in atrial and ventricular muscle.
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Bellemann P, Scholz H. Dissociation of theophylline uptake and inotropic effect in myocardial tissue: influence of temperature, pH and calcium. Br J Pharmacol 1975; 54:75-81. [PMID: 237594 PMCID: PMC1666387 DOI: 10.1111/j.1476-5381.1975.tb07412.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
1. The myocardial uptake and the positive inotropic effect of theophylline (100 mug/ml; 0.56 mM) were studied in isolated electrically driven guinea-pig hearts perfused by the Langendorff technique under various extracellular conditions. [3H]-theophylline was used. 2. Variations in temperature, hydrogen ion and calcium ion concentrations of the perfusion media changed the time course and magnitude of the effect of theophylline on myocardial twitch tension but did not affect the time course and amount of theophylline uptake. 3. Under all conditions, the build-up of the positive inotropic effect of theophylline was about three times faster than the uptake of the drug into the heart. 4. Since no relationship could be found between theophylline uptake and inotropic effect, the cardiac positive inotropic response to theophylline is thought unlikely to be due mainly to an interaction of the drug with intracellular receptor sites but is assumed to occur via an effect of the drug on the sarcolemma, that is at a site which the drug reaches before it enters the intracellular space.
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Endoh M, Wagner J, Schümann HJ. Influence of temperature on the positive inotropic effects mediated by α- and β-adrenoceptors in the isolated rabbit papillary muscle. Naunyn Schmiedebergs Arch Pharmacol 1975. [DOI: 10.1007/bf00632638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Muñoz-Ramírez H, Ryan CF, Buckner CK. Studies on the temperature-dependent sensitivity of mouse atria to adrenergic drugs. Eur J Pharmacol 1975; 30:73-8. [PMID: 235439 DOI: 10.1016/0014-2999(75)90205-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The sensitivity of mouse atria (chronotropic response) to beta-adrenergic receptor antagonists was examined at 37 and 26 degrees C under various experimental conditions. When isoproterenol was used as agonist, at 37 degrees C, the pA2 value (from pA2 plots) for propranolol was 8.86 and the slope of the regression line was 0.54. At 26 degrees C, the pA2 value for propranolol was 9.2 and the slope was 0.7. In the presence of tropolone, 10-5 M, the values for pA2 and slope of the regression lines were, respectively, 9.0 and 0.90 at 37 degrees C and 9.17 and 0.98 at 26 degrees C. In other words, decreasing antagonism was prevented by low temperature and tropolone. Isoproterenol was potentiated by tropolone and low temperature, but the effects of low temperature were reduced by tropolone. With sotalol as antagonist, there was greated blockade (dose ratios) of the effects of isoproterenol at 26 than at 37 degrees C. When nylidrin, a non-catecholamine, was used as agonist there was no temperature-dependent sensitivity to sotalol. Furthermore, nylidrin was not potentiated by low temperature. The data show that the observed degree of beta-receptor antagonism can be altered by changing the bath temperature and suggest that this effect is related to COMT activity or an influence of agonist disposition in the tissue.
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Reinhardt D, Wagner J, Schümann HJ. Effects of papaverine on the rabbit ileum under the influence of altered temperature and extracellular Ca2+. Eur J Pharmacol 1974; 29:279-83. [PMID: 4374361 DOI: 10.1016/0014-2999(74)90027-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Wagner J, Reinhardt D, Schümann HJ. Comparison of the bronchodilator and cardiovascular actions of isoprenaline, Th 1165a, terbutaline and salbutamol in cats and isolated organ preparations. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1974; 162:49-62. [PMID: 4810839 DOI: 10.1007/bf01851883] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Wagner J, Reinhardt D. Characterization of the adrenoceptors mediating the positive ino- and chronotropic effect of phenylephrine on isolated atria from guinea pigs and rabbits by means of adrenolytic drugs. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1974; 282:295-306. [PMID: 4152593 DOI: 10.1007/bf00501237] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tirri R, Harri MN, Laitinen L. Lowered chronotropic sensitivity of rat and frog hearts to sympathomimetic amines following cold acclimation. ACTA PHYSIOLOGICA SCANDINAVICA 1974; 90:260-6. [PMID: 4544401 DOI: 10.1111/j.1748-1716.1974.tb05585.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Wöppel W, Trendelenburg U. Temperature-dependent supersensitivity of isolated atria to catecholamines. Eur J Pharmacol 1973; 23:302-5. [PMID: 4746746 DOI: 10.1016/0014-2999(73)90100-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Reinhardt D, Wagner J, Schümann HJ. Changes of the beta-receptor binding sites of the rabbit ileum under the influence of high temperature. EXPERIENTIA 1973; 29:830-2. [PMID: 4724717 DOI: 10.1007/bf01946315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Wagner J, Reinhardt D, Schümann HJ. Influence of the metabolic state on the action of phenylephrine on rabbit ileum, guinea-pig vas deferens and atrium. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1973; 276:63-70. [PMID: 4266251 DOI: 10.1007/bf00500779] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Wagner J, Reinhardt D, Schumann HJ. Influence of temperature on the sensitivity of adrenergic -receptors. EXPERIENTIA 1972; 28:1325-6. [PMID: 4638906 DOI: 10.1007/bf01965324] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Schümann HJ, Wagner J, Reinhardt D. Sensitivity changes of adrenergic -receptors induced by alterations of the metabolic state of isolated organs. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1972; 275:105-13. [PMID: 4264166 DOI: 10.1007/bf00505071] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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