Responses of isolated dog cerebral and peripheral arteries to prostaglandins after application of aspirin and polyphloretin phosphate.

In helically cut strips of dog cerebral, coronary, mesenteric and femoral arteries, the contractile response to prostaglandin (PG) F2alpha, and E2, relative to contractions induced by 30 mM K+, did not appreciably differ, whereas relaxations induced by PGE1 relative to those induced by 10(-4) M papaverine were significantly different; the least in cerebral arteries and the greatest in mesenteric arteries. The relaxation of human cerebral arteries in response to PGE1 was similar to that of dog cerebral arteries. Treatment for 60 min with polyphloretin phosphate (3 X 10(-5) and 10(-4) g/ml) suppressed the contractile response to PGF2alpha and E2 but did not alter the response to 25 mM K+. The relaxing effect of PGE1 was not influenced. Aspirin (5 X 10(-5) and 2 X 10(-4) M) significantly potentiated the contractile response to PGF2alpha and E2 but did not alter the relaxation induced by PGE1. In contrast, contractions induced by serotonin were attenuated. It is concluded that dog cerebral, coronary, mesenteric and femoral arteries relaxed differently in response to PGE1. It appears that arterial responses to vasoconstricting PGs, but not to the vasodilating PG, are significantly attenuated by polyphloretin phosphate and potentiated by aspirin.