The effect of nipradilol on the isoproterenol-induced depression of contractions in the cat soleus muscle.
The effect of nipradilol on the isoproterelol-induced depression of contractions of the soleus muscle of the anesthetized cats was studied. Isoproterenol (0.3 microg/kg) injected intravenously decreased the tension and degree of fusion of incomplete tetanic contractions of the soleus muscle of the anesthetized cats. The effect of isoproterenol was blocked by nipradilol (> or = 3 microg/kg), desnitro-nipradilol (> or = 10 microg/kg) and propranolol (> or = 10 microg/kg), but not by nitroglycerin (10-100 microg/kg). Nipradilol (30 microg/kg) and desnitronipradilol (300 microg/kg) almost completely antagonized the depressor effects of isoproterenol. These results coupled with evidence that nipradilol does not penetrate the blood-brain barrier indicate that nipradilol exerts an anti-tremor action by blocking peripheral beta2-adrenoceptors.
Tanaka
T
T
Gifu Research Laboratory, JBC Inc., Kaizu-gun, Japan.
Murata
N
N
Yamauchi
Y
Y
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D002415:Cats; D005260:Female; D007545:Isoproterenol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D011412:Propanolamines / Q000494:pharmacology*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C036089:nipradilol; D007545:Isoproterenol