Histamine causes all except -: (A) Aeriolar dilatation, (B) Increased permeability of venules, (C) Constriction of large aeries, (D) Platelet aggregation
Answer is D. Histamine causes aeriolar dilation rapidly increases vascular permeability by inducing venular endothelial contraction formation of inter-endothelial gaps endothelial activation ref robbins pathology 9thed page 45