PMID: 2870152Feb 1, 1986

The effect of varying carbachol concentration on the slope of Schild plots of selective beta-adrenoceptor antagonists in the carbachol-contracted guinea-pig trachea

The Journal of Pharmacy and Pharmacology
R A KeithA I Salama

Abstract

The effect of varying the level of smooth muscle tone induced by carbachol on the Schild analysis of atenolol (beta 1-selective) and ICI 118,551 (beta 2-selective) with salbutamol as agonist, on the guinea-pig tracheal preparation has been examined. When 10(-6) M carbachol was used to induce near-maximal smooth muscle tone, Schild plot slopes for atenolol and ICI 118,551 were less than 1. Slopes of Schild plots for both drugs were equivalent to 1 when 10(-7) M carbachol was used to produce approximately half-maximal smooth muscle tone. Depletion of neuronal noradrenaline by prior treatment with reserpine had no effect on the Schild analysis. Salbutamol produced maximal relaxation and was more potent when tone was induced with 10(-7) M carbachol, but was less effective at 10(-6) M carbachol. Pretreatment with reserpine increased the potency of salbutamol at each concentration of carbachol. The results suggest that either the level of smooth muscle tone or an unknown effect associated with a high level of smooth muscle tone induced by carbachol may contribute to low slope values of Schild plots of selective beta-adrenoceptor antagonists in the carbachol-contracted guinea-pig trachea. The carbachol-contracted guinea-pig trachea ca...Continue Reading

References

Jul 1, 1977·British Journal of Pharmacology·J L ImbsC G Wermuth
May 1, 1974·European Journal of Pharmacology·C K BucknerM O'Connor
Feb 1, 1969·European Journal of Pharmacology·B Levy, B E Wilkenfeld
Jun 1, 1965·The Journal of Pharmacy and Pharmacology·J W CONSTANTINE

Citations

Apr 1, 1990·The American Review of Respiratory Disease·R D KrellF J Brown
Jul 12, 2005·Journal of Smooth Muscle Research = Nihon Heikatsukin Gakkai Kikanshi·Yoshio TanakaK Koike
Feb 18, 2011·British Journal of Pharmacology·J Daniel HothersallJames R Baker

Related Concepts

ICI 118551, hydrochloride
Adrenergic beta-Antagonists
Sultanol
Tenormin
Carboptic
Cavia porcellus
Inotropism
Muscle Relaxation Phase
Muscle Tonus
Smooth Muscle

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