Question

4) During Reperfusion there is both an influx of calcium into the mitochondrial matrix and an increased generation of Reactive oxygen species by the mitochondria. How do these 2 events collectively contribute to mitochondrial rupture and ultimately apoptosis (cell death) of those myocardial cells. Please refer to specific channels, etc. in your response.

5) Exercise training can minimize the amount of damage to the myocardium if an ischemia-reperfusion occurs. Based on evidence (largely from rodent models), how much exercise is needed in order to provide this myocardial protection, and how long does this protection last/persist following cessation of exercise.

6) Exercise training has been shown to increase the expression of ATP-sensitive potassium (KATP) channels on the sarcolemma of myocardial cells. Provide an explanation for how having more sarcolemmal KATP channels can reduce the amount of calcium accumulation in the cytosol during ischemia. Your response should include the function of these channels as well as how they impact action potentials in myocardial contractile cells.

7) Exercise training results in increased intracellular stores of nitrite, including in the myocardium. During myocardial ischemia, nitrite is reduced back to the molecule nitric oxide in those cells. Name 2 proteins or structures that nitric oxide modifies (via nitrosylation), and describe how modification of these proteins prevents mitochondrial damage during reperfusion.

Answer 1

4, mitochondria play a important role in the homeostasis of the body's cells..In the total myocardial cell volume mitochondria having role in modulation and maintenance of organ function..It provides cellular energy to the heart it depends upon oxygen supply by the coronary artery to maintain energy requirement of the myocardial cells..when there is less coronary blood flow there will be less oxygen delivery to the myocardium make myocardial ischemia and cellular events which alter the mitochondrial function cause cell death and functional impairment that extend after the restoration of coronary blood flow to the heart..

5, High energy synthesis that mitochondria plays a major role in regulating more disease especially in the heart..physical activity can improve the cardiac function and adoption of heart muscle to interfere metabolic demands..impaired mitochondria metabolism contribute to number of cardiovascular disease..12weeks of aerobic exercise can minimise the amount of ischemia - reperfusion occur..

6, Having more sarcolemmal KATP channels can reduce the amount of calcium accumulation in the cytosol during ischemia..KATP channels is a sensitive potassium channel..it is found in plasma membrane and subcellular membrane..it is classified as sarcolemmal, and mitochondrial..these both needed for ischemic preconditioning to its effects..when there is blockage in mitoKATP with 5- hydroxydecanoic acidity inhibits the cardioprotection..sarcolemma KATP accumulation prevent cellular calcium overload and decrease cardiac muscle contraction..There is increased mitochondrial dysfunction plays a role in necrotic and adoptic reperfusion injury..