Structure, cytochemistry, endocytic activity, and immunoglobulin (Fc) receptors of rat testicular interstitial‐tissue macrophages

Abstract

Macrophages are common in rat testicular interstitial tissues. Interstitial-tissue macrophages were characterized using ultrastructural, cytochemical, immunologic, and autoradiographic methods. Testicular interstitial-tissue macrophages have a single indented nucleus, paranuclear Golgi complex, rough endoplasmic reticulum, coated vesicles, and numerous heterogeneous lysosomal vacuoles. Long filopodia and lamellopodia extend from the macrophage cell body into the lymphatic space. Macrophages are usually found adjacent to Leydig cells, and numerous Leydig cell processes are inserted into coated membrane invaginations on the macrophage surface. Secondary lysosoma1 vacuoles in the macrophage are cytochemically reactive for acid phosphatase (trimetaphosphatase) and aryl sulfatase. Testicular interstitial macrophages are endocytically active, avidly incorporating exogenously administered trypan blue dye and monomeric plutonium-citrate. Macrophages were isolated from the testes by allowing them to adhere to glass. The isolated macrophages were found to have receptors for the Fc portion of immunoglobulin G on their surface. The association of macrophages with Leydig cells and their endocytic and immunologic activity suggests that these cells may play an important role(s) in testicular functions. In addition, the ability of these cells to incorporate exogenous materials indicates that they could have a role in gonadal toxicity reactions.

The mononuclear phagocyte system of the mouse defined by immunohistochemical localization of antigen F4/80: macrophages of endocrine organs.

“…A recent paper has described the isolation and characterization of rat testicular interstitial macrophages (24).…”

Building the mammalian testis: origins, differentiation, and assembly of the component cell populations

“…Testicular macrophages have a distinctive phenotype, associating with Leydig cells to form junctional complexes (Christensen and Gillim 1969;Miller et al 1983;Hutson 1990). In the mature testis, macrophages influence steroidogenesis in Leydig cells, secreting 25-hydroxycholesterol, which is acquired by ALCs and used in testosterone synthesis (Lukyanenko et al , 2001Nes et al 2000).…”

Bismuth Uptake in Rat Testicular Macrophages: A Follow-up Observation Suggesting that Bismuth Alters Interactions Between Testicular Macrophages and Leydig Cells

“…It was therefore suggested that bismuth had accumulated in rat Leydig cells, exhibiting a direct toxic effect on these cells. Because macrophages are found in the testis at a relatively high concentration (Miller et al 1983;Hutson 1990) and have been shown to phagocytose a variety of foreign substances (Wei et al 1988), we were interested in determining if these cells also accumulate bismuth. Because testicular macrophages exert local influences on Leydig cells, accumulation of bismuth in these cells could have functional significance (Hutson 1994(Hutson ,1998.…”