Effects of cyclooxygenase inhibitors, prostaglandins F2 alpha and I2, on isolated coeliac and basilar arteries of alloxan-diabetic dogs.
The effects of prostaglandin synthetase inhibitors PGF2 alpha and PGI2 on the tone of isolated basilar and coeliac arteries were studied in healthy and alloxan-diabetic dogs. PGF2 alpha (1 mumol 1-1) produced a significantly higher tone in diabetic basilar arteries (1.15 +/- 0.16 mN) than in normal cerebral vessels (0.7 +/- 0.10 mN). By contrast, the contractile responses of normal and diabetic coeliac arteries to PGF2 alpha did not differ. The cyclooxygenase inhibitors indomethacin (3 mumol 1-1) and suprofen (0.58 mumol 1-1) potentiated the PGF2 alpha-evoked contractions in all of the vessels studied. The percent potentiation was greater (50-60%) in the basilar arteries from alloxan-treated dogs than in normal basilar vessels (22-30%). There was not such a difference between diabetic and normal coeliac arteries. Prostacyclin produced a concentration-related relaxation in the presence of indomethacin or indomethacin + PGF2 alpha. The relaxant potencies of PGI2 were similar in the vessels from metabolically healthy and diabetic dogs. The IC50 values for PGI2 were 11.6 +/- 1.3 and 11.8 +/- 1.8 nmol 1-1 in normal and diabetic basilar arteries, respectively; they were 25.4 +/- 3.2 and 26.2 +/- 3.9 nmol 1-1 in control and alloxan-treated coeliac vessels. These results indicate that normal and diabetic vessels may have differential reactivity to cyclooxygenase inhibitors, this difference being dependent on the vascular region.
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002445:Celiac Artery / Q000187:drug effects; D016861:Cyclooxygenase Inhibitors; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D015237:Dinoprost; D004285:Dogs; D011464:Epoprostenol / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D011460:Prostaglandins F / Q000494:pharmacology*; D013496:Suprofen / Q000494:pharmacology
D016861:Cyclooxygenase Inhibitors; D011460:Prostaglandins F; D013496:Suprofen; D015237:Dinoprost; D011464:Epoprostenol; D007213:Indomethacin