This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'All are functions of leukotrienes except: \nSelect and explain. \nA. Increase vascular permeability., B. Broncho constrictors., C. Platelet aggregators., D. Counter regulatory compounds of immune system.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Satyanarayan -562\nLeukotrienes are implicated in asthma, inflammatory reactions, hypersensitivity and heart attacks. Leukotrienes cause contraction of smooth muscles, bronchoconstriction, vasoconstriction, adhesion of white blood cells and release of lysosomal enzymes. Lipoxins are involved in vasoactive, and immunoregulatory functions. There is a strong evidence to support that lipoxins act as counter\xa0regulatory compounds of immune response.', 'role': 'assistant'}]