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: Pathology
[{'content': 'Increased permeability in acute inflammation is due to \nSelect and explain. \nA. Histamine, B. IL-2, C. TGF-p, D. FGF', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Formation of endothelial gaps in venules, i.e. immediate transient response is the most common mechanism causing increased vascular permeability in acute inflammation,\nMediators involved in this mechanism are\n\ni. Immediate (more important): Histamine, bradykinin, leukotrienes, neuropeptide substance P.\nii. Somewhat delayed: IL-1, TNF, IFNγ', 'role': 'assistant'}]