Langendorff Retrograde Heart Perfusion: An Ex Vivo Technique to Perfuse Isolated Mouse Heart

After euthanizing an 8- to 10-week-old male C57BL/6 mouse, use tissue forceps to lift the skin of the xiphoid. Then, using tissue scissors, make a minor lateral incision through the skin. Perform a blunt dissection between the skin and fascia. Extend the skin incision toward the axillae in a V-shape on both sides and continue the incision through the rib cage.

Then, using tissue forceps, clamp the sternum and deflect the rib cage upward to fully expose the heart and lungs. Using curved forceps, peel off the pericardium. If the thymus gland covers the great vessels, use two curved forceps to tear the thymus gland toward both sides. Then, gently pull the base of the heart toward the tail until the aorta and its branch arteries are visible as a Y-shaped blood vessel.

Transect the aorta at the left common carotid artery. Then, cut the brachiocephalic artery. Excise the heart and immediately immerse it in a Petri dish containing Tyrode's solution to wash and pump out the residual blood. Then, transfer the heart to another Petri dish containing solution 1.

Under a stereomicroscope, using fine iris scissors, trim any surplus tissue. Expel air bubbles from the syringe. Then, with the assistance of two straight tying forceps, perform retrograde aortic cannulation, taking care that the whole cannulation process is performed under the liquid surface. Adjust the cannulation depth such that the cannula tip is in the ascending aorta, taking care not to penetrate the aortic valves.

Then, with a pre-knot 3-0 suture, ligate the aorta to the cannula notch. Gently inject solution 1 from the syringe to flush out the residual blood. Then, connect the cannulated heart to the Langendorff apparatus, taking care not to introduce any air bubbles into the heart. After connecting the cannulated heart to the Langendorff apparatus, perfuse the heart with solution 1 for approximately 2 minutes.