I want to draw blood from a Wistar rat, 4 times in an hour and each time I don't need more than 2 cc of blood. I wanted to use cardiac puncture since I didn't manage to get this amount of blood from other sites. In different sources, cardiac puncture is known as a terminal procedure, meaning that it can be used only one time, because the creature will die after that. But I want to know that can this procedure be done several times under special conditions (e.g. needle size, etc.) and the creature stays alive?
Cardiac puncture can only be done one time. As you remove the needle from the heart, the blood leaks out of the heart and into the thoracic cavity. Are you testing the blood for oxygen levels, CBC, chem, something else?
I want to measure insulin, how about if I use a smaller needle?
I agree with the previous answer. If you need several blood samples - you will need to use a peripheral blood vessel - tail vein or saphenous vein most probably and with a very small needle - and it is most likely you will not be able to collect from the same site consecutively. Maybe alternate between the right and the left saphenous vein and start collecting from the most distal end possible so you can move up the vein for the next collection.
A better option is to find an alternate method to measure insulin the uses a smaller amount of blood sample (serum) - so there is less to collect.
Hope that helps.
Nós realizamos somente 1 punção. Várias coelhas morreram.
I agree with the earlier comments that you need another method to measure insulin that doesn't require 2 ml blood. However, if you only need to collect over an hour you can keep the rat anaesthetised the whole time. This could allow you to insert an indwelling catheter into the jugular vein through which you should be able to collect the blood. General anaesthesia could also allow you to take several cardiac punctures over the hour if they are done well and quickly.
In addition to all the other comments/proposals you can cannulate the tail vein and take your blood samples. I also agree that 2ml of blood sampling per time is a lot.
Another important consideration is that you propose to remove a total of 8 mL of blood within an hour. Assuming the rat weighs 300g, you are bleeding off ~30% of the blood volume, which causes significant sympathetic and hormonal compensatory responses. The experimental conditions will be greatly altered between the first and last withdrawal, which will likely invalidate your measurements.
I appreciate your answer, Dr. Klabunde. How much blood can be appropriate for an insulin measurement procedure which described earlier? (4 times in an hour)
I'll be grateful if you give me a reference for your answer.
I'll be also happy if anyone else answers, too!
Cardiac puncture is used as a terminal procedure in a fully anaesthetised animal - hence it can only be done once. Your ethics committee will not allow it.
A quick google search or a consult with your analytical kit supplier(s) would help you in your search for an insulin measurement procedure that requires less samples.
We have done insulin measurements (1 serum sample collection only) from blood samples collected from mice (about 1 mL of whole blood) - I refer to my colleague's work - "Adiposity in Female B6C3F1 mice...." [Radiation Research 173, 333-341 (2010)].
Good luck.
Cardiac puncture is only one time procedure, once we puncture heart there will be chances of death of the animal. We can collect 2cc blood easily by puncturing retro orbital plexus of animal by a expert hand...
Good luck
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