Contraction of lymphatic muscle cells is crucial for propelling lymph through the body. These cells are a hybrid of cardiac, smooth and skeletal muscle types. Experimental evidence on whole cannulated vessels shows that the acto-myosin complex in these individual cells facilitates phasic contractions which in produce most of the pumping action. The smooth muscle components regulate the diameter, and thus the resistance to flow from adjacent vessels. The contractile signature of lymphatics has not been studied at the single-cell level. We aim to induce active contractions in single isolated human lymphatic muscle cells via a custom-built bioreactor and subsequently measure their biomechanics on a substrate through traction force microscopy.
Image: Lymphatic muscle cells in the wall of a rat mesenteric lymphatic vessel. The bulge at the centre of the image indicates the location of a lymphatic valve. From Zawieja et al., Am J Physiol Heart Circ Physiol 302:H643-H653, 2012.