<prompt> In acute inflammation due to the contraction of endothelial cell cytoskeleton, which of the following results?Delayed transient increase in permeabilityEarly transient increase in permeabilityDelayed permanent increase in permeabilityEarly permanent increase in permeability  <response>: Endothelial cell contraction leading to intercellular gaps in postcapillary venules is the most common cause of increased vascular permeability. Endothelial cell contractionoccurs rapidly after binding of histamine, bradykinin, leukotrienes, and many other mediators to specific receptors, and is usually sho-lived 15 to 30 minutes. A slower and more prolonged retraction of endothelial cells, resulting from changes in the cytoskeleton, may be induced by cytokines such as tumor necrosis factor TNF and interleukin-1 IL-1. This reaction may take 4 to 6 hours to develop after the initial trigger and persist for 24 hours or more. Robbins Basic Pathology, 9th edition, page 34 