The main challenge that I would be facing in the laboratory this summer was to be whether or not I could isolate and mount a rat pulmonary artery on a pressure myograph system. A pressure myograph is used to model near physiological conditions ex vivo. The pressure myograph chamber, where all of the exciting things happen, has two cannulas that are facing opposite of each other. An excised vessel, in this case, a pulmonary artery, has a cannula slid into both ends and is secured in place by 11-0 suture material. The vessel completes the circuit of the system and pressurization can occur, which is controlled by a connected laptop with Myoview software. After mounting and pressurizing the vessel, we are able to subject the vessel to a series of molecules of interest.
I had watched my mentor isolate a pulmonary artery once before it was my turn to try. It was a new thing for the lab, so there was not really any guidance for me other than lung anatomy diagrams. The heart and lungs had been removed from the animal and kept under solution in a round glass dish with wax on the bottom, to provide a surface for pins to be placed to keep the lungs and heart from floating around. All of the isolation was performed under a microscope with microsurgical tools, so I had to learn to keep my hands steady or else I would make a cut in the wrong place and potentially ruin the pulmonary artery. The first isolation lacked finesse and mostly consisted of making an unsure cut and hoping that a gush of blood would not result. But the isolation was still a success in multiple senses of the word: I isolated a useable segment of the artery, figured out a good way to pin down the heart and lungs, and most importantly, I gained experience in navigating and isolating the pulmonary artery.
My mentor always made it clear that we had the whole summer to figure out the isolation, so any difficulties that I might have should not worry me; there would always be another day. Luckily, I seemed to have an aptitude for doing such isolations, as my second attempt, and subsequent runs, lead to a successful myograph mount and experiment run. Performing these experiments is something that I enjoy doing as they challenge me both physically and mentally and allow me to learn a lot of things.
The image below is a diagram of rat lungs that includes the lobe names, pulmonary arteries, pulmonary veins, and bronchus. I have been tasked with isolating the left pulmonary artery, predominantly the section between the first branch and second branch (the second branch not in photo but the pulmonary artery branches in the same places as the bronchus, so where the bronchus branches in the left lung is where I stop isolating). Photo credit to google image search.