| Abstract: | Coronary arteries were excised from pentobarbital anesthetized normal dogs. The isolated coronary arteries were placed in an oxigenated KRB bathing solution maintained at 37 degrees C and pH 7.4 changes in the basal tone were measured. The addition of glomerulopressin to the bathing solution produced a decrease of 26 +/- 1.5 mg of the basal tone. This decrease was prolonged for more than 40 minutes. Several inhibitors of prostaglandins synthesis were added to the bath such as corticosterone (2 X 10(-5) M), indomethacin (6 X 10(-6) M), acetylsalicylic acid (1.8 X 10(-4) M) and tranylcypromine (4 X 10(-4) M). All these inhibitors blocked the action of glomerulopressin. We conclude that glomerulopressin relaxes the coronary arteries and that this relaxation may be mediated through the novobiosynthesis of prostaglandins. |
