Cellular and Humoral Dynamics in the Periarterial Lymphatic Sheaths of Rat Spleens

Abstract

Humoral and cellular dynamics in the periarterial lymphatic sheath (PALS) of the splenic white pulp were investigated in regards to the lymph flow and the architecture of the deep lymphatics in rat spleens. The effects of the splenic venous pressure on the lymph flow were also examined. We found a remarkable depletion of lymphocytes in the PALS and strong lymph flow to the deep lymphatics from the red pulp when the spleen was perfused via the splenic artery at a high speed with a high venous pressure. It was evident that lymphocyte depletion in the PALS depended on the venous pressure during the perfusion. Hemorrhage and lymphocyte depletion in the PALS also occurred after the ligature of the splenic vein. The migration of charcoal particles into the PALS via the red pulp was observed after intravenous or direct injection of charcoal particles. However, the briding channels in the marginal zone (MZ were always free of charcoal particles. The existence of deep lymphatics was confirmed around the central arteries which were more than 20 μm in diameter. The ligature of the thoracic duct resulted in the dilatation of the deep lymphatics and intercellular spaces which were easily recognized as the termination of the splenic lymphatics. The terminal lymphatics were localized only in the PALS but not in the follicles. Therefore, the PALS might be considered to act as a central station of the extra‐vascular pathway which is connected to both the deep lymphatics and the MZ bridging channels. ACTA PATHOL. JPN. 34: 1301–1311, 1984.

Periarterial lymphoid sheath in the rat spleen: A light, transmission, and scanning electron microscopic study

“…7-10. through which the central artery ran. Free cells were easily washed away by perfusion; a strong lymph flow may exist, as reported by Koshikawa et al (1984).…”

Local lymphogenic migration pathway in normal mouse spleen

“…Several reports have been presented concerning the structure of deep lymphatic vessels in the spleen in various animals (Hokazono and Miyoshi 1984;Janout and Weiss 1972;Katsuki 1925;Koshikawa et al 1984;Pellas and Weiss 1990;Sasou and Sugai 1992;Snook 1946). However, none of these reports has identified these vessels by using highly specific immunohistochemical methods.…”

“…Various techniques, including the dye injection method (Barcroft and Florey 1928;Dubreuil et al 1975;Godart and Hamilton 1963;Koshikawa et al 1984), scanning and transmission electron microscopy (Hokazono and Miyoshi 1984), and examination of plastic semi-thin sections by light microscopy (Pellas and Weiss 1990), have been used to observe lymphatic vessels in the spleen. All these methods, however, require sophisticated skills or equipment.…”

Quantitative Assessment of a Change of Hemosiderin Deposition with Age in Splenic Compartments of Rats.

“…It has been reported that the spleen possesses an efferent lymphatic drainage, but no afferent lymph vessels (Snook 1946;Fukuda 1963) A lymphaticdependent fluid flow crossing the splenic compartments has been postulated by Janout and Weiss (1972). The PALS is considered to act as the center of the lymphatic pathway in the spleen (Koshikawa et al 1984). Cell movement from the marginal zone to the PALS or the follicles has also been reported (Sasuo et al 1980;Brelinska and Pilgrim 1982).…”

“…This is thought to result from movement of hemosiderin-laden macrophages into the PALS. The initial lymphatic vessels are localized in the proximal PALS (Snook 1946;Koshikawa et al 1984;Sasou and Sugai 1992). Hemosiderin-laden macrophages, in part, may be further carried along the artery to the hilus within the PALS by this efferent lymphatic wave which flows in the opposite direction of the arterial blood flow.…”