Which of the following statements regarding cytokines is incorrect?

C. Platelet-activating factor (PAF) is a major cytokine that results in platelet aggregation, bronchoconstriction, and increased vascular permeability.

DISCUSSION: Cytokines are soluble peptide molecules that are synthesized and secreted by a number of cell types in response to injury, inflammation, and infection. Cytokines, which include the interleukins, tumor necrosis factor, colonystimulating factors, and the interferons, comprise only one category of inflammatory mediators involved in the host  Basic surgical background (Biochemistry, Fluids, Electrolytes, Hemostasis, Shock, Surgical Infections, Wound Healing …etc) Asir Surgery MCQs Bank. © 1422H-2002- first impression © This project was raised after an idia by Dr. Gharama Al-Shehri (consultant surgeon). 6 Developed and typed by Dr. Ghazi Al-Shumrani (intern). response. Endotoxin, complement fragments, eicosanoids, kinins, nitric oxide, oxidants, and PAF are noncytokine mediators that also have important roles in the systemic inflammatory response. IL-1 and TNF-a, like other cytokines, have multiple effects on target cells and potentiate the actions of other mediators to produce an amplified inflammatory response. TNF-a is thought to play a central role in the stress response, particularly in response to endotoxemia.