Answer
Edema:- It is a condition in which fluid is abnormally accumulated under the skin in interstitium. Amount of fluid is determined by the balance of homeostasis of fluid and secretion of fluid in interstitium and removal of fluid from interstitium. Edema is caused by a toxin released by bacterium Bacillus anthracis. Anthrax toxin is composed of cell binding protein antigen (PA) and two ezymatic comonent edema factor (EF) and lethal factor (LF) For edema condition following consequences occur
1. PA is assembled into heptameric or octameric ring shaped oligomer.
2. Ring shaped oligomer is bound to 3 or 4 EF toxin molecules. 3.Then cell endocytoses PA-EF complex to inside the cell.
4.In cell due to low pH endosome is converted to a cation-selective channel.
5.EF toxins are driven into cytosol along the pH gradient.
6.Inside cytosol EF toxin acts as Ca2+ and calmodulin dependent adenylate cyclase that increases CAMP level about 200 folds then normal conc.
7.High CAMP conc. causes : (a.) Water homeostasis imbalance. (b.) Signalling pathway off balance and impared macrophages function which ultiamately causes Edema.
Work Step by Step
Edema:- It is a condition in which fluid is abnormally accumulated under the skin in interstitium. Amount of fluid is determined by the balance of homeostasis of fluid and secretion of fluid in interstitium and removal of fluid from interstitium. Edema is caused by a toxin released by bacterium Bacillus anthracis. Anthrax toxin is composed of cell binding protein antigen (PA) and two ezymatic comonent edema factor (EF) and lethal factor (LF) For edema condition following consequences occur
1. PA is assembled into heptameric or octameric ring shaped oligomer.
2. Ring shaped oligomer is bound to 3 or 4 EF toxin molecules. 3.Then cell endocytoses PA-EF complex to inside the cell.
4.In cell due to low pH endosome is converted to a cation-selective channel.
5.EF toxins are driven into cytosol along the pH gradient.
6.Inside cytosol EF toxin acts as Ca2+ and calmodulin dependent adenylate cyclase that increases CAMP level about 200 folds then normal conc.
7.High CAMP conc. causes : (a.) Water homeostasis imbalance. (b.) Signalling pathway off balance and impared macrophages function which ultiamately causes Edema.
