beta-adrenoceptor blockade with diphenylhydantoin (DPH).
Diphenylhydantoin (DPH) (20 x 10(-6) to 80 x 10(-6) M/kg) blocked the depressor responses to isoproterenol in spinal, bilaterally vagotomized and atropine pretreated cats; depressor responses to histamine were unaffected; DPH shifted the isoproterenol concentration-response curve to the right in isolated guinea pig tracheal chain preparation, isolated rabbit ileum and isolated perfused heart of frog. The results suggest that DPH has a specific beta-adrenoceptor blocking action and the blockade appears to be competitive in nature as shown by PA2 and PA10 values.
D000319:Adrenergic beta-Antagonists; D000818:Animals; D001001:Anura; D001285:Atropine / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D010672:Phenytoin / Q000494:pharmacology*; D011817:Rabbits; D011898:Ranidae; D014628:Vagotomy
D000319:Adrenergic beta-Antagonists; D010672:Phenytoin; D001285:Atropine