Human Hormones

Prostacyclin is a lipid-derived hormone found in the human body.
Secretion and Production

Prostacyclin is produced in the endothelial cells from prostaglandin by the action of enzyme prostacyclin synthase. It acts chiefly to prevent platelet formation and clumping involved in blood clotting. It is also an effective vasodilator.
Pharmacological Uses

Synthetic prostacyclin is administered intravenously, subcutaneously, or by inhalation as a vasodilator in severe Reynaud’s phenomenon, ischemia of a limb, and pulmonary hypertension.

Leukotrienes are autocrine and paracrine eicosanoid lipid mediators derived from arachidonic acid by 5-lipoxygenase.
Synthesis and Production

Leukotrienes are synthesized in the cell from arachidonic acid by 5-lipoxygenase. They are involved in asthmatic and allergic reactions and act to sustain inflammatory reactions.
Pharmacological Uses

There is no current medical usage for synthetic leukotrienes. Rather, leukotriene inhibitors act to suppress the asthma-inducing effects of their secretion.