Cyclooxygenase-2 derived thromboxane A2 and reactive oxygen species mediate flow-induced constrictions of venules in hyperhomocysteinemia

In hyperhomocysteinemia increases in flow/shear stress increases the production of COX-2-derived TxA2, and reactive oxygen species - that overcome the dilator effects of NO and prostaglandins - eliciting constrictions in skeletal muscle venules; changes which can increase vascular resistance and favor thrombus formation in the venular circulation.