Following MI, staining of cardiac tissue with TTC within 12 hours of infarction showed red color. This red colour is seen:
TTC stands for Tetrazolium Chloride. I remember that TTC is used in histology to assess tissue viability. In the context of a myocardial infarction (MI), the staining is used to differentiate viable from necrotic tissue. The red color comes from the reduction of TTC to formazan. But wait, how does that work?
So, in viable myocardial cells, the mitochondrial dehydrogenases are active. These enzymes reduce TTC to formazan, which is a red-colored compound. Therefore, viable tissue would stain red, and infarcted tissue (where the cells are dead and the enzymes are inactive) would not take up the stain, appearing white. But the question says that after 12 hours of infarction, the tissue showed red color. That seems contradictory because after an MI, the affected area should be non-viable. Wait, maybe the timing is important here. Let me recall the timeline of MI changes.
After an MI, the initial changes are subtle. Within a few hours, the affected tissue becomes pale due to loss of blood flow. However, the actual necrosis takes longer, maybe 4-6 hours for the cells to die and release enzymes. Wait, but if the MI is within 12 hours, maybe the tissue is still viable? Or maybe the question is a trick? Or perhaps the options are about where the red color is seen, like in the infarcted area versus viable tissue.
Wait, the user's correct answer is missing. Let me check the original question again. The user wrote: "Correct Answer: . " with a period. Maybe they intended to include the answer but forgot. Let me proceed with the assumption that the correct answer is that the red color is in the viable tissue. Because if the MI is within 12 hours, maybe the tissue is still viable in some areas, but that doesn't make sense. Wait, no—TTC staining is used to show viable tissue as red, and the infarcted area remains unstained. So if the question is asking where the red color is seen, it should be in the viable myocardium, not the infarcted area.
Wait, the question says "staining of cardiac tissue with TTC within 12 hours of infarction showed red color." So the red color is in the viable tissue. So if the options include something like "in the viable myocardium" or "in the non-infarcted regions," that would be correct. The infarcted area would be unstained. So the red color is in the areas that are still viable, not the infarcted part. Therefore, the correct answer would be an option stating that the red color is seen in the viable tissue.
Now, for the incorrect options, common distractors might be that the red color is in the infarcted area (incorrect because the enzymes are inactive there), or in the interstitial spaces (no, it's in the viable cells), or that it's due to a different stain (like hematoxylin-eosin).