Plasma derived inflammatory mediator

Ans. is ‘c’ i.e., C3

.       The central process in the complement cascade ( for both classical and alterante pathway) is the avtivation of C3, which is the major component of complement.

. Ans. is ‘a’ i.e., IgG and IgM

Ans. is ‘b’ i.e., Bronchodilatation

Effects of bradykin in

• Increased vascular permeability.
• Mediation of pain (Direct stimulation of free nerve ending and T PG production)
• Vasodilatation (Largely mediated by endothelial cell NO & PGI2).
• Visceral smooth muscle contraction : – Bronchoconstriction, Intestinal & uterine smooth muscle contraction.

Stimulation of epithelial ion transport and fluid secretion in airways and GIT.

Ans. is ‘b’ i.e., Pain at the site of inflammation

Ans. is ‘a’ i.e., Kininogen

Ans. C: C3

Ans. is ‘a’ i.e., MAC

Ans. is ‘c’ i.e., C_sa

Ans. is ‘c’ i.e., C5a > ‘b’ i.e., C4a

C_5a.,C_3a.,to a lesser extent C_4a—> are called anaphylotoxin because they have effects similar to those of mast cell mediators that are involved in the reaction called anaphylaxis. These effects are due to stimulation of histamine release by these anaphylotoxin. The effects are increased vascular permeability and vasodilatation.

Ans. d. Increased vascular permeability

• The role of bradykinin in process of inflammation is to increase vascular permeability.
• “Bradykinin increases vascular permeability and causes contraction of smooth muscle, dilation of blood vessels, and pain when injected into the skin.”- Robbins 8/e p65

Kinins

• Kinins are vasoactive peptides derived from plasma proteins, called kininogens, by the action of specific proteases called kallikreins.
• The kinin and coagulation systems are also intimately connected.
• The active form of factor XII, factor XIIa, converts plasma prekallikrein into an active proteolytic form, the enzyme kallikrein, which cleaves a plasma glycoprotein precursor, high-molecular-weight kininogen, to produce bradykinin
• Bradykinin increases vascular permeability and causes contraction of smooth muscle, dilation of blood vessels, and pain when injected into the skinQ.
• These effects are similar to those of histamine.
• The action of bradykinin is short-lived, because it is quickly inactivated by an enzyme called kininase.
• Any remaining kinin is inactivated during passage of plasma through the lung by angiotensin-converting enzyme.
• Kallikrein itself is a potent activator of Hageman factor, allowing for autocatalytic amplification of the initial stimulus.
• Kallikrein has chemotactic activity, and it also directly converts CS to the chemoattractant product C5aQ.