Immunohistological observations on the spleen B lymphocyte populations from whole-body irradiated rats

The effects of a single exposure to caesium gamma rays administered to rats at high dose rate have been observed on their spleen B lymphocyte populations. These effects increase with the dose as well as with the time, at least within the following ranges of experimental conditions: from 0 to 12 Gy and observation times of 1 and 3 days after irradiation. Doses less than or equal to 1.50 Gy lead to only a slight reduction of the B lymphocyte populations. On the contrary, doses equal to or greater than 3.50 Gy are extremely destructive for the spleen B lymphocytes. The non-circulating B lymphocyte population of the marginal zone compartment seems more susceptible to ionizing radiations than the circulating B lymphocyte population of the follicular compartment.