Leukotriene D₄ (LTD₄) is one of the leukotrienes. Its main function in the body is to induce the contraction of smooth muscle, resulting in bronchoconstriction and vasoconstriction. It also increases vascular permeability. LTD₄ is released by basophils. Other leukotrienes that function in a similar manner are leukotrienes C₄ and E₄. Pharmacological agents that inhibit the function of these leukotrienes are leukotriene receptor antagonists (e.g., zafirlukast, montelukast) and are useful for asthmatic individuals.^[1]