Lessons from the Langendorff
Do you need help with Langendorff technique?
Here are some essential pro tips and practical advice from isolated heart expert Dr. Melanie White (University of Sydney) for Langendorff heart and perfusion.
Lessons from the Langendorff: Heart
1. The condition of the animal will influence the function of the heart
If your animal is stressed in any way this is likely to influence the function of the heart. Likewise, if the animal is diseased in any way this will also influence the function of the heart.
Pro Tip: If your heart is not performing at the end of baseline, you should take a closer look at the cadaver. There might be some sort of indicator that the animal had an issue which wasn't otherwise detectable until you performed the surgical procedure.
2. Heparin is important
Heparin is incredibly important, especially in small rodent models. That's because any kind of blood clot is akin to an ischemic insult.
3. Contractility is maintained when the heart is submerged
We find better contractility is maintained throughout a perfusion protocol when the heart is submerged in a warm buffer, be it crystalloid or any additional buffers that you may choose.
4. Ensure you can see the end of the cannula through the aorta
We find that it is important that you can see the end of the cannula.
Pro Tip: You should be able to gently touch the heart and can see the cannula through the aorta. If you can't see the end of the cannula it might indicate that it has perforated through the aortic valve and that is going to influence your system.
5. Homemade balloons are tricky but worth the effort!
We use homemade balloons. They are tricky! But because you can change the size, it is well worth the effort.
Pro Tip: What is the best material to use to make a homemade balloon? The heart size and pathology being studied are important factors when selecting the material to use since each material has both advantages and disadvantages. Ideally, the wall tension balloon should remain constant and not contribute significantly to the measurement, while the volume should uniformly expand. Additionally, the ability to see through will assist in ensuring that there are no air bubbles in the balloon.
6. Practice, practice, practice
Practice is key! Langendorff is not an easy technique. Mastery comes with time. So practice, practice, practice!
Lessons from the Langendorff: Perfusion
7. Keep dedicated glassware
Don't swap glassware and don't use glassware for multiple purposes. If the glassware is for a buffer, it should only be used for that single buffer.
8. Water source is important
Your choice of water source is incredibly important. If your hearts aren't making it through baseline, try checking or changing your water source.
9. Everything needs to be filtered repeatedly
Everything needs to be filtered, and it needs to be filtered repeatedly, especially if you are using a small rodent model. Even small particulates are akin to an ischemic insult.
10. Air bubbles are akin to inducing an ischemic insult
The same can be said for air bubbles - they can cause an ischemic insult. For that reason, we use an inline air bubble trap.
11. Ensure appropriate cleaning protocols
We also want to ensure appropriate cleaning protocols for everything! If there is any kind of bacteria or mold, that could lead to cardio-toxic effects.
Pro Tip: Clean your air stones!
12. Release tubing from peristaltic pump when not in use
To ensure you maintain your flow rates for as long as possible over many experiments, it is important to release the tubing from the peristaltic pump. Keeping it attached adds additional pressure when not in use.
Our Langendorff solutions
We offer a range of solutions for both constant flow and constant perfusion pressure Langendorff setups. Our Radnoti Langendorff Foundation Systems can be customized for either constant pressure or flow for perfusing both mice and rat hearts. Radnoti's modular systems are made from high-quality, crystalline glassware and include PowerLab data acquisition hardware, LabChart data analysis software, and high-quality components for measuring cardiac parameters. See here for more information about our Radnoti Langendorff Systems.
Our Panlab Langendorff System is also a great option for those who are wanting a compact, all-in-one solution. This space-saving, lightweight system allows you to easily switch between constant pressure and flow using an STH pump controller (included in the system).
See here for a brief overview of the Panlab Langendorff System and its components.
ARC DECRA Research Fellow
School of Medicine
University of Sydney
About the speaker...
Dr. Melanie White is a member of the Charles Perkins Society, a Heart Foundation Future Leader Fellow and teaches senior students in the discipline of Pathology at the University of Sydney School of Medicine.
Her research interests include understanding more about how cells adapt to their changing environment by altering proteins using post-translational modifications. Her team’s work centers on asking these questions in clinically relevant models of myocardial ischemia (heart attack), type 2 diabetes and obesity.
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