Pharmacological actions of a new β‐adrenoceptor agonist, MJ‐9184–1, in anaesthetized cats Journal Articles uri icon

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abstract

  • Summary The effects of (–)‐isoprenaline and the new β‐adrenoceptor agonist, MJ‐9184–1, on the lungs, on the cardiovascular system, and on slow contracting skeletal muscle have been compared in cats under chloralose anaesthesia. Both amines reduced the increases in airways resistance produced by 5‐HT, depressed incomplete tetanic contractions of the soleus muscle, lowered the blood pressure and produced an increase in heart rate. In comparison with (‐)‐isoprenaline, MJ‐9184–1 had a long duration of action. The effects of MJ‐9184–1 and (–)‐isoprenaline were antagonized by the β‐adrenoceptor antagonist, propranolol. MJ‐9184–1 was approximately half as potent as (–)‐isoprenaline in its effects on pulmonary resistance and soleus muscle contractility, and one seventh as potent in producing chronotropic effects in the heart. These results suggest that MJ‐9184–1 possesses some specificity as a β2 receptor stimulant.

publication date

  • November 1972