Which ONE of the following is not an endogenous mediator of increased vascular permeability?

The answer is A. Angiotensin is produced by the action of renin on angiotensinogen and is involved in the secretion of aldosterone and in pressor effects

C3a and C5a (B) are part of the complement cascade and are activated C3 and C5; they act by liberating histamine from mast cells.

5-hydroxytryptamine (C) or serotonin causes increased vascular permeability in rodents but not in man.

Kallikrein (D) is produced by the activation of Hageman factor (factor XII) producing prekallikrein activator which converts prekallikrein to kallikrein.

Prostaglandin E2 (E) is secreted by polymorphs which are phagocytically active, it does not cause increased permeability itself but potentiates the activity of other factors.