Intestinal prostacyclin and thromboxane production in irreversible hemorrhagic shock
Alemayehu, A.; Sawmiller, D.; Chou, B.S.; Chou, C.C.
Circulatory Shock 23(2): 119-130
1987
ISSN/ISBN: 0092-6213 PMID: 3315288 Document Number: 304224
Arterial and intestinal venous blood were sampled every hour for measurement of thromboxane B2 (TXB2) and 6-keto-PGF1.alpha., stable metabolites of thromboxane A2 and prostacyclin, respectively, in dogs subjected to hemorrhagic hypotension at 32.8 .+-. 1.4 mm Hg for 3 h, followed by reinfusion of the remaining shed blood. Control dogs were treated alike without hypotension. Arterial and intestinal venous TXB2 significantly increased during hypotensive and post-transfusion periods, the venous concentration being significantly higher than the corresponding arterial. The arterial and venous 6-keto-PGF1.alpha. increased during hypotension but decreased during posttransfusion periods. Furthermore, arterial and venous TXB2 to 6-keto-PGF1.alpha. concentration ratio increased. Intestinal TXB2 release (blood flow .times. arteriovenous concentration difference) increased progressively, whereas 6-keto-PGF1.alpha. release decreased. No significant changes occurred in the control dogs. This study shows an imbalance in intestinal production and release of TXA2 and PGI2, in favor of TXA2 during severe hemorrhagic hypotension and after blood transfusion. The imbalance may contribute to the development of irreversible hemorrhagic shock and reperfusion injury.