Effects of interleukin-3 injection on supraventricular amoeboid microglial cells in neonatal BALB/c and athymic mice.

The present study investigated the effects of interleukin-3 (IL-3) on supraventricular amoeboid microglial cells (SAMC) of neonatal BALB/c and athymic mice. After four consecutive daily intraperitoneal injections of IL-3 at the age of 1 day postnatum and perfusion at the age of 5 days, BALB/c and athymic mice showed a 20% and 37% increase, respectively, in the number of Mac-1 positive SAMC. In mice receiving seven successive injections of IL-3 and perfused at the age of 8 days postnatum, Mac-1 labelled SAMC were increased by 14% and 19%, respectively.

Effects of thymosin alpha1 on the development of amoeboid microglial cells in the corpus callosum of neonatal BALB/c and athymic mice.

The present study investigated the effects of intraperitoneal injections of thymosin alpha1 on the supraventricular amoeboid microglial cells (SAMC) in the newborn athymic and normal BALB/c mice. The microglial cells labelled by the lectin GSA I-B4 and the antibody Mac-1 showed a 27% reduction in number in the athymic mice receiving thymosin alpha1 injections compared with those receiving vehicle injections, and a 37% reduction in BALB/c mice receiving thymosin alpha1 injections compared with those receiving vehicle injections. Some of the SAMC in both BALB/c and athymic mice receiving thymosin alpha1 injections became ramified, while the remainder still exhibited their normal amoeboid appearance with few filopodial processes.

In vivo expression of inducible nitric oxide synthase in supraventricular amoeboid microglial cells in neonatal BALB/c and athymic mice.

The present study investigated whether the supraventricular amoeboid microglial cells (SAMC) in neonatal BALB/c and athymic nude mice were able to express inducible nitric oxide synthase (iNOS) after intraperitoneal injections of lipopolysaccharide (LPS) or interferon-gamma (IFN-gamma). The results showed that iNOS, undetectable in these cells in vehicle injected mice, could clearly be demonstrated immunohistochemically in a large number of them in LPS treated normal and mutant mice. Only a few iNOS-positive SAMC were observed in IFN-gamma injected mice.

A qualitative and quantitative study of the glial cells in normal and athymic mice.

A qualitative and quantitative light and electron microscopic analysis of the glial cells in the supraventricular part of the corpus callosum of the neonatal and adult homozygous athymic nude (nu/nu) and normal BALB/c (+/+) mice was carried out to determine the possible contribution of nude gene mutation to glial cell development. Quantitative cell counts using toluidine blue stained serial callosal sections of 0.5 micron thickness showed that the overall glial cell population was significantly reduced in both neonatal and adult athymic mice.

A comparative Mac-1 immunocytochemical and lectin histochemical study of microglial cells in the normal and athymic mice.

The number of microglial cells in the supraventricular part of the corpus callosum stained with Mac-1 antibody (against CR3 antigens) and the intensity of staining were studied in both the homozygous athymic nude mouse (nu/nu) and normal BALB/c mouse (+/+). For quantitative analysis, the mean microglial cell counts (expressed in terms of packing density) from 40 microns thick immunostained sections were obtained and tested by analysis of variance. The Mac-1 positive cells in neonatal nude mice were slightly less intensely stained than those of their normal littermates.