Supraependymal macrophages of third ventricle of hamster: Morphological, functional and histochemical characterization in situ and in culture

Abstract

Supraependymal cells (SECs) of the young hamster's third ventricle have been examined by scanning and transmission electron microscopy. Of special interest were cells with the surface morphology and ultrastructure of macrophages, which were found in largest numbers in 12--15-day-old females and males. In the ciliated areas SECs are generally smooth and rounded; in nonciliated areas, they frequently have surface ruffles, blebs and microprocesses. SECs were frequently seen to be dividing or fusing. The macrophage-like cells are characterized by prominent Golgi zones and numerous large vacuoles, and frequently contain inclusions in their cytoplasm which resemble intraventricular cell processes, cytoplasmic protrusions from ependymal cells and cellular debris. We have demonstrated that supraependymal macrophage-like cells phagocytose latex beads injected into the ventricles of the brain. Supraependymal cells from 12-day-old hamsters were grown in tissue culture. Phagocytic, cytochemical and surface ultrastructural studies were then done sequentially on the same population of cells. These studies revealed the cells to be actively phagocytic as well as strongly esterase positive and peroxidase negative, consistent with their classification in the macrophage/monocyte category. The surface ruffles, ridges and microprocesses were also characteristic of the SECs seen in situ with scanning electron microscopy and of the macrophages cultured from the peritoneum and peripheral blood of the same hamsters. On the basis of cellular morphology, cytochemical staining characteristics and functional response to exposure to foreign particles both in situ and in cell culture, we have demonstrated that supraependymal cells of the third ventricle of the hamster are phagocytes that resemble cells of the macrophage/monocyte line. It is suggested that they constitute a resident macrophage system of the ventricles of the brain.

Effects of surface wettability, flow, and protein concentration on macrophage and astrocyte adhesion in an in vitro model of central nervous system catheter obstruction

“…Mus musculus IC‐21 macrophages derived from SV‐40 transformed peritoneal macrophages with phagocytic properties were obtained from ATCC (Manassas, VA). These were originally obtained from a C57BL/6 mouse (ATCC product number TIB‐186) and were chosen primarily because of their mature phenotype16 and characteristic similarity to supraependymal macrophages found bound to CNS implants 17. After rinsing with Dulbecco's Phosphate Buffered Saline (DPBS, Invitrogen), macrophages were cultured in RPMI‐1640 media with 25 m M 4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid HEPES, 1% penicillin–streptomycin (Sigma, St. Louis, MO), 1% GlutaMAX (Invitrogen, Carlsbad, CA), 1% sodium pyruvate (Invitrogen), and 10% fetal bovine serum (FBS, Sigma).…”

Epiplexus cells in the embryos of the turtle, Trionyx sinensis.

“…It has been suggested that the pleomorphic microappendages on the intraventricular macrophages including epiplexus-and supraependymal cells probably reflect different degrees of activation or stages of development (STURROcK,1979;BLEIER and ALBRECHT, 1980), In our study of the epiplexus cells in prenatal rats treated with 6-amino-nicotinamide, it has been demonstrated that blebbing is an immediate expression of these cells in the initial stage of phagocytosis (ZING, TSENG and WONG, 1985). In the transmission electron microscope, the epiplexus cells in turtle embryos showed structural resemblances to cells in higher vertebrates (CARPENTER, MCCARTHY and BORISON, 1970;ZING, 1979ZING, , 1981STURROCK, 1979) in that they contained dense bodies which were probably lysosomes.…”

Method for the identification of brain macrophages/phagocytic cells in vitro

“…Whilc latex beads have been employed by others in investigating phagocytic activity in vitro (Bleier and Albrecht, 1980;Ling et al, 1983;Giulian and Baker: 1986), the present procedure represents an extension of this application. In previous studies, beads were used to assess phagocytosis by isolated, identified cells.…”