myocardial infarction in mice - Heart tissue slices contract in tetrazolium staining. How can this be solved?
Answers
Answer:
Explanation:
Myocardial infarction results from myocardial ischemia and is a serious problem for the ischemic patient because it compromises the ability of the heart to pump blood through loss of contractile mass. Over the past 30 years there has been a concerted effort in cardiology to identify interventions which would make the heart more resistant to infarction. While other surrogate end-points have been considered such as enzyme release, recovery of post ischemic function or indexes of viability in cultured cells, only actual measurement of tissue necrosis can be relied upon to confirm a true anti-infarct intervention. The key to such research is the availability of a method which allows the early detection of myocardial infarction in a whole heart. Tetrazolium staining has emerged as the most popular method.
This technique relies on the ability of dehydrogenase enzymes and cofactors in the tissue to react with tetrazolium salts to form a formazan pigment. It can be argued that tissue lacking either of these would not be able to survive and is therefore dead or destined to die. On the other hand, tissue that stains positively is not necessarily healthy and may succumb hours or even days latter. For that reason, the longer the reperfusion period after an ischemic insult, the more reliable the method becomes for discriminating between dead and viable tissue. Reperfusion times of less than 3 hrs (2 hrs for crystalloid-perfused Langendorff hearts) are unreliable with this method since insufficient washout time has occurred. Three days of reperfusion is considered optimal. Unfortunately, the need for a recovery model increases the complexity of a 3-day reperfusion by an order of magnitude. For that reason, most investigators settle on 3-6 hours of reperfusion for an open-chest study. Beyond 3 days of reperfusion remodeling within the infarct again makes the assessment unreliable due to scar shrinkage.
Ischemic myocardium is exquisitely sensitive to temperature. It has been reported that cooling salvages 7% of the risk zone per degree of cooling. Thus allowing a rabbit heart to cool just 2 degrees to 35� C will reduce average infarct size from 35% to 21% in untreated rabbits undergoing a 30 min coronary branch occlusion. Inadequate temperature control is a major source of noise in infarct size studies.
Explanation:
Briefly:
•Heart is harvested from mouse
•To have smooth cutting / slices, heart is wrapped in plastic bag (sealed) in -20°C for around 20-25min, it becomes semi solid.
•Slicing of heart (1mm thick) - At this point slices are flat and smooth
•Incubate slices in pre-warmed tetrazolium at 37°C at hot plate / heating pad for 20 minutes
(this step distorts the tissue structure (not any more flat)
•Incubate in Pre-warmed 10% formalin for 20min on heating pad.
•Photos.
°Can any body suggest the remedy for this.
<<>>>Note: This does not matter whether MI was performed or not.
hope this answer may helps u.. ☺️