[Effects of adenosine compounds of the vascular bed and effects of dilazep, theophylline, and indomethacin on blood flow changes of the postocclusive renal vessels].

In anesthetized dogs, intrarenal arterial injections of adenosine (Ads) and adenosine 5' monophosphate (AMP) caused transient, vasoconstrictions, but those of adenosine 5' diphosphate (ADP) and adenosine 5' triphosphate (ATP) caused vasodilations. All of these agents produced marked vasodilations in the mesenteric and femoral vascular beds. An i.v. injection of dilazep (10--30 microng/kg) enhanced significnatly the effects of Ads and AMP at these three vascular beds, whereas this compound had no effects on results with ADP, ATP, norepinephrine and angiotensin. Administration of theophylline (10--30 mg/kg) given intravenously attenuated Ads and AMP actions, but had no effects on the other four agents. Renal vasoconstrictions induced by Ads. AMP, norepinephrine and angiotensin were followed by slight vasodilations which were abolished by indomethacin (2--5 mg/kg) given intravenously. Based on these findings postocclusive renal vascular responses were examined. The responses were divided into two phases. Phase1 was the initial decrease and phase2 was the successive gradual increase in renal blood flow (RBF). Phase 1 was significantly potentiated by dilazep, but inhibited by theophylline. Phase2 was abolished by indomethacin. These results indicate that the postocclusive renal vascular responses may be mediated through Ads and/or AMP and prostaglandins released from the kidney.