Which of the following arachnidonic acid metabolites is a pulmonary vasoconstrictor?

Thromboxane is a metabolite of arachidonic acid that acts as a potent pulmonary vasoconstrictor. It is primarily produced by platelets and plays a crucial role in various physiological processes, including the regulation of vascular tone. When thromboxane is released, it causes the smooth muscle in the pulmonary vasculature to contract, leading to vasoconstriction.

This effect can be particularly significant during certain physiological or pathological conditions, such as during hypoxia or in some states of pulmonary hypertension, where the balance of vasodilators and vasoconstrictors is disrupted. The unique action of thromboxane in this context highlights its importance in the overall regulation of pulmonary circulation and acute responses to changes in the body's environment.

Understanding the role of thromboxane also emphasizes the balance of arachidonic acid metabolites in cardiovascular health, as different metabolites can have opposing effects on vascular function.