LAD-Ligation: A Murine Model of Myocardial Infarction

Summary

This video demonstrates how to use a fast and reliable model to study pathobiological and pathophysiological processes of myocardial ischemia.

Abstract

Research models of infarction and myocardial ischemia are essential to investigate the acute and chronic pathobiological and pathophysiological processes in myocardial ischemia and to develop and optimize future treatment.

Two different methods of creating myocardial ischemia are performed in laboratory rodents. The first method is to create cryo infarction, a fast but inaccurate technique, where a cryo-pen is applied on the surface of the heart (1-3). Using this method the scientist can not guarantee that the cryo-scar leads to ischemia, also a vast myocardial injury is created that shows pathophysiological side effects that are not related to myocardial infarction. The second method is the permanent ligation of the left anterior descending artery (LAD). Here the LAD is ligated with one single stitch, forming an ischemia that can be seen almost immediately. By closing the LAD, no further blood flow is permitted in that area, while the surrounding myocardial tissue is nearly not affected. This surgical procedure imitates the pathobiological and pathophysiological aspects occurring in infarction-related myocardial ischemia.

The method introduced in this video demonstrates the surgical procedure of a mouse infarction model by ligating the LAD. This model is convenient for pathobiological and pathophysiological as well as immunobiological studies on cardiac infarction. The shown technique provides high accuracy and correlates well with histological sections.

Protocol

Balb/C mice weighing a minimum of 20g at an age of 8 to 12 weeks are purchased from Charles River (Sandhofer Weg 7, D-97633 Sulzfeld). Mice are housed under conventional conditions, fed standard mouse pellets and water ad libitum. Anesthetize mouse with isoflurane (2%) using an induction chamber. Shave the neck area and the left side of the ribcage and disinfect using 80% ethanol. Place the mouse on its back and place a facemask over its nose and mouth to keep up the anesth…

Discussion

In summary, this video visualizes the LAD-ligation model step-by-step and identifies LAD-ligations in mice as easily feasible surgical procedures.