FINE STRUCTURE AND FUNCTION OF CUTANEOUS AND RENAL LYMPHATIC CAPILLARY

The lymphatic capillary can be differentiated with certain ty from the blood capillary or the postcapillary venule and identified only by means of electron microscope. The author observed the ultrastructure of the cutaneous and renal lymphatic and studied the functions under the pathological conditions produced experimentally, such as edema, trauma with or without foreign body and osmotic nephrosis. The lymphatic capillary was characterized by its irregular contour, the presence of luminal and abluminal projections of the endothelia, rich collagen fibers, bundles and fibrils around the vessels, absent or scanty basement membrane and loose endothelial junctions. In the lumen, there were found frequently fine electron dense particles, fibrin and myelin-like structures and rarely blood cells and destroyed cells after microinjection. Some endothelial junctions were opened when sucrose or saline solution was injected and dextran was administered. In case of charcoal injection, the junctions were closed. Some charcoal particles were attached to the lymphatic wall and found in the lumina or in the cytoplasma of the endothelium. Interstitial edema was always observed. The microinjection of Chinese ink was the best method to investigate the lymphatic. Fluid, fibrin, foreign bodies, various cells and destroyed cellls are transported through the lymphatic; thus lymphatics are thought to play an important role in the removal of edema, foreign bodies and the healing of wound or hemorrhage