Which mediators are released by white blood cells during the inflammatory response?

• A. Histamine, bradykinin, and prostaglandins
• B. Insulin, glucagon, and somatostatin
• C. Adrenaline, cortisol, aldosterone
• D. Dopamine, norepinephrine, serotonin

Answer: (A)

Inflammation works through chemical messengers released by immune cells to coordinate blood flow, vessel permeability, and recruitment of more cells to the area. Histamine, bradykinin, and prostaglandins are classic mediators released during this response by white blood cells and related immune cells. Histamine is stored in mast cells and basophils; when released it causes rapid dilation of nearby blood vessels and makes venules more permeable, leading to redness, warmth, and swelling. Bradykinin is generated in the inflamed tissue and contributes further to vasodilation and permeability, and it also stimulates pain receptors, helping to signal trouble to the body. Prostaglandins, produced by leukocytes and other cells through the cyclooxygenase pathway, amplify inflammation by promoting vasodilation, increasing sensitivity to pain, and supporting fever. These mediators together drive the characteristic signs of inflammation and are distinct from hormones like insulin or adrenaline or from neurotransmitters that are not primary mediators released by white blood cells in this context.