Studies on the perifollicular region of the rat's spleen

Abstract

A marginal sinus, formed by the anastomosed terminations of white pulp capillaries, bounds the inner edge of the marginal zone. The endothelial lining on the nodular surface is complete. Pores appear along the lateral aspect thus allowing blood to pass freely into the interstices of the marginal zone. A dense aggregation of Marshall's metalophil cells occurs in the region of the marginal sinus. Such cells are lacking in the marginal zone.Intravenous injections of particulate matter were used to determine the course of blood flow and phagocytic potential. Ten minutes after injections, particles were found to be dispersed among the cells of the marginal zone. None were found in the marginal metalophils. In four hours the particles had cleared the marginal zone and were within red pulp macrophages. In a few rats, the marginal metalophils reacted positively to tests for iron. It is concluded that marginal metalophils represent a large reserve of potential phagocytes situated at a point where blood first leaves capillaries to enter tissue interstices.

Immunocytochemical Localization of Catechol-O-Methyltransferase in Lymphoid Tissue and Bone Marrow of Rat

“…In the rat spleen, COMT-positive cells were found in the white pulp, marginal zone and the perinodular ring between the white pulp and the marginal zone. This distribution, especially that of the COMT-positive cells forming the perinodular ring, corresponds closely to the metalophil cells or marginal metalophils described by Snook (36) . Cytochemical studies indicate that the marginal metalophils may differ somewhat from other metalophil cells in that they show very weak phagocytic (36) and non-specific esterase activity (31), a constant level of acid phosphatase (31) and stain specifically for monoamine oxidase (39) .…”

“…This distribution, especially that of the COMT-positive cells forming the perinodular ring, corresponds closely to the metalophil cells or marginal metalophils described by Snook (36) . Cytochemical studies indicate that the marginal metalophils may differ somewhat from other metalophil cells in that they show very weak phagocytic (36) and non-specific esterase activity (31), a constant level of acid phosphatase (31) and stain specifically for monoamine oxidase (39) . However, despite these differences, the metalophil cells of the white pulp and marginal zone as well as those in the perinodular ring appear to be reticular cells (31).…”

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

“…There were only few hemosiderinladen macrophages in the marginal zone and these were weakly stained by the iron reaction. The same finding was reported by Snook (1964). According to McFadden (1968), the marginal zone, generally free of active macrophages, has functions other than phagocytic activity.…”

Macrophages of the Splenic Marginal Zone Are Essential for Trapping of Blood-Borne Particulate Antigen but Dispensable for Induction of Specific T Cell Responses

“…MZM were first described by their ability to retain and internalize haptenated polysaccharides (4,5). MM form a thin rim at the inner border of the marginal zone (6), show affinity for silver (metallophilic), and are less phagocytic than MZM (1,7).…”