Prostanoid release from ex vivo perfused canine arteries and veins: effects of prolonged perfusion, intermittent perfusion, as well as exposure to exogenous arachidonic acid, thrombin and bradykinin.
Regulation of prostanoid release from ex vivo perfused vessel segments is not fully understood. A series of perfusion experiments were performed with canine arteries and veins to define certain regulatory phenomena. Arteries were perfused with pulsatile flow of 90 ml/min at a pressure of 100 mmHg, and veins with nonpulsatile flow of 90 ml/min at a pressure of 7 mmHg. Segments were perfused with Hanks' balanced salt solution for five 15-min periods with the perfusate exchanged after each study period. With onset of perfusion, there was an initial burst of prostacyclin release to 127 +/- 40 pg/mm2, declining to 32 +/- 10 pg/mm2 after 60 minutes (p less than 0.005). If perfusion continued for 5.5 hours, there was a stable release period between 1 and 3 hours, followed by a very slow decline. At that time addition of arachidonic acid (AA) increased prostacyclin release six-fold (p less than 0.01). Vessels perfused for 1 hour and then rested for another hour, responded to reperfusion at the second onset of flow with a two-fold increase in prostacyclin release (p less than 0.01). Vessels perfused with thrombin, bradykinin or AA (either added to each perfusate or only to the last perfusate) exhibited greater prostacyclin release than did control segments. Release of thromboxane steadily declined with time in all parts of the study, and only increased with the addition of AA to the perfusate.(ABSTRACT TRUNCATED AT 250 WORDS)
Brunkwall
J S
JS
Department of Surgery, University of Lund, Malmö General Hospital, Sweden.
Stanley
J C
JC
Kresowik
T F
TF
Graham
L M
LM
Burkel
W E
WE
Bergqvist
D
D
D015121:6-Ketoprostaglandin F1 alpha / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism / Q000494:pharmacology*; D001808:Blood Vessels / Q000378:metabolism*; D001920:Bradykinin / Q000494:pharmacology*; D004285:Dogs; D011464:Epoprostenol / Q000378:metabolism*; D010477:Perfusion; D013917:Thrombin / Q000494:pharmacology*; D013931:Thromboxanes / Q000378:metabolism*
D001095:Arachidonic Acids; D013931:Thromboxanes; D016718:Arachidonic Acid; D015121:6-Ketoprostaglandin F1 alpha; D011464:Epoprostenol; D013917:Thrombin; D001920:Bradykinin