Changes in splenic uptake pattern associated with X-ray irradiation

Abstract

Purpose To evaluate the splenic uptake function after irradiation with high-energy X-rays. Materials and methods Fourteen male Wistar rats were distributed into three groups. Group 1 (n = 6) – control, non-irradiated; Group 2 (n = 4) – animals that were irradiated and studied 24 h after irradiation; and Group 3 (n = 4) – animals that were irradiated and studied 48 h after irradiation. The animals were irradiated with 8 Gy X-rays in the abdominal region. According with the groups, after 24 or 48 h, 1 ml/kg of a 50% colloidal carbon solution was injected in the left internal jugular vein. After 40 min, the spleens were removed for histological studies. Macrophages containing carbon pigments in their cytoplasms were counted in 16 consecutive microscopic fields, and their means were considered as the uptake pattern of each animal. Results In the control groups, carbon pigments were captured by macrophages in the red and white pulps, while in the irradiated groups, the uptake in the marginal zone, around the white pulp, was enhanced. There was no disorder on the splenic parenchyma or necrosis in histological analyzes. Qualitatively rare apoptotic events were observed, with no difference between control and irradiated animals. Conclusion The high-energy X-ray, used in radiotherapy, modifies the splenic clearance, enhancing the amount of marginal zone macrophages containing colloid particles. This radiation was not associated with morphological changes, nor with necrosis or apoptosis of splenic tissue.

Megavoltage radiotherapy effects on organs of the reticuloendothelial system

“…The splenic macrophages containing carbon pigments were uniformly distributed in the splenic parenchyma of the control group. However, in the irradiated groups B and C, they were located mainly in the marginal zone around white pulps, as previously described 8 ( Fig. 3 ).…”

“…This study aimed to verify the megavoltage radiotherapy effects on RES, based on the previous results, which have shown that the concentration of the colloidal uptake activity in the splenic marginal zone after irradiation with a single dose of high-energy XR 8 , as well as a reduction of the hepatic uptake of a technetium-phytate solution injected in the animals 9 . The reduction of the hepatic uptake activity might be related with radiation-induced damage to the liver parenchyma that was histologically investigated in this work.…”

“…Previously, the same group of this work has published that the high-energy XR, used in radiotherapy, modifies the splenic clearance, enhancing the amount of marginal zone macrophages containing colloid particles 8 . Studies with technetium-phytate confirmed the splenic clearance modification in irradiated animals, revealing an enhancement of nearly 260% of the splenic uptake activity 9 .…”

An Experimental Model of Proton-Beam-Induced Radiation Dermatitis In Vivo

“…Changes in the mass and morphology of these organs may serve as additional markers for assessing the impact of proton irradiation on the hematopoietic and immune systems. Currently, there is a lack of research on lymphoid organs, and existing literature focuses on the development of immunosuppression in various compartments of the immune system during high-dose total X-ray irradiation in the short-term period after irradiation [61][62][63]. These changes are often associated with a sharp increase in cellular destruction, leading to loss of lymphocytes, and complete inhibition of cellular mitotic activity and differentiation [64].…”