[Immunohistochemical analysis of splenic tissue in rats with destruction of the hypothalamic structures].

The immunoenzyme histochemical technique to stain the IgM- and IgD-bearing cells was used to study the morphometric characteristics of B-lymphocyte-dependent zones in spleen white pulp of Wistar rats (intact, sham operated and after cortex or hypothalamic lesions). In the groups of sham-operated and cortex-lesioned rats it has been shown the increase of spleen weight 7 days after the operation due to the increase of the red pulp weight. The white pulp compartment's ratio is not affected.

Failure to detect immune deficiency in rats after prenatal or early postnatal irradiation.

We have looked for medium-term sequelae in the immune system of rats that had been X-irradiated (0-2 Gy whole-body irradiation) during prenatal or early postnatal life. At an age of 8 weeks the histology of the spleen was normal, and so was the distribution of B and T lymphocytes. The serum immunoglobulin levels were not significantly altered, even when the different isotypes were considered.

Lymphocyte disappearance and reappearance after a single whole-body irradiation dose of 5 Gy.

The effects of a single exposure to 5 Grays of caesium gamma rays administered at a high-dose rate were investigated in rat lymphocyte populations. Such a dose completely depleted the B-cell population but never totally depleted the T-cell population. T and B lymphocytes reappeared in the spleen after 10-15 days and somewhat later in the mesenteric lymph nodes and Peyer's patches.

Studies of long-term continuous irradiations using daily doses ranging from 0.07 to 0.30 Gy on the B lymphoid system of the rat.

The effects of a continuous exposure to cobalt gamma rays administered to rats at a daily dose of 0, 0.07, 0.12, 0.