VISUALIZATION OF THE LYMPHATICS OF THE HEART AND THE MEDIASTINAL DRAINAGE PATHWAYS IN THE LIVING CYNOMOLGOUS (MACACA MULATTA) MONKEY

Abstract

Our interest in the effects of impaired cardiac lymph drainage on coronary atherosclerosisled us to study the cardiac lymphatic anatomy in the monkey, generally considered the idealexperimental animal for examining coronary artery disorders. Short-term and long-term studiesto visualize the cardiac lymphatic system and its mediastinal drainage pathways in 14 livingmonkeys confirmed that the epicardial collecting lymphatic anatomy is comparable to that ofman, dog, and pig. These lymphatics, and particular lymphatic drainage to the cardiac lymphnode in the right mediastinum, are difficult to visualize, in good part, because lymph uptake ofsuch tracers as India Ink and T1824 blue dye is extremely slow. By modifying our techniques andtaking cognizance of the slow lymphatic uptake of the tracers, we have been more successful invisualizing the mediastinal cardiac lymph node. Though our studies confirm that the lymphaticdrainage of the monkey heart is similar to that in other mammals, we conclude that the “monkeymodel” has several drawbacks to study the effects of impaired cardiac lymph flow because of thelaborious requirements to visualize successfully the cardiac lymph node. Perhaps thedevelopment of new markers would make this lymphatic system more approachable forexperimental investigation