Premium
Actions of some sympathomimetic bronchodilator and beta‐adrenoceptor blocking drugs on contractions of the cat soleus muscle
Author(s) -
BOWMAN W. C.,
NOTT M. W.
Publication year - 1970
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1970.tb10334.x
Subject(s) - orciprenaline , isoprenaline , salbutamol , propranolol , chemistry , medicine , soleus muscle , agonist , practolol , bronchodilator , antagonist , endocrinology , skeletal muscle , receptor , stimulation , asthma
1 (–)‐Isoprenaline, salbutamol, orciprenaline and quinterenol injected intravenously decreased the tension and degree of fusion of incomplete tetanic contractions of the soleus muscle of the anaesthetized cat. 2 Under the most sensitive conditions, the smallest effective dose of (–)‐isoprenaline was of the order of 0.01 μg/kg intravenously. Salbutamol was usually 6–10 times, orciprenaline 20–30 times and quinterenol about 35 times less potent than isoprenaline. The effects of salbutamol were about 1.6 times, of orciprenaline about 1.8 times and of quinterenol more than 20 times as long lasting as those of (–)‐isoprenaline. 3 The effects of the sympathomimetic amines were blocked by propranolol, H56/28, H35/25 and butoxamine but not by ICI 50172. The combined results with agonists and antagonists indicate that the receptors involved can be classified as of the β 2 type. 4 The effect of the amines on the cat soleus muscle appears to be analogous to that causing enhancement of physiological tremor in man, which suggests that skeletal muscle tremor may be an occasional unwanted side effect of the use of these bronchodilators.