<prompt> Increased permeability in acute inflammation is due to?HistamineIL-2TGF-3FGF  <response>: Ans. is a i.e., Histamine Formation of endothelial gaps in venules, i.e. immediate transient response is the most common mechanism causing increased vascular permeability in acute inflammation. Mediators involved in this mechanism are :- Immediate more impoant : Histamine, bradykinin, leukotrienes, neuropeptide substance P. Somewhat delayed: IL-1, TNF, IFN-y 