Alterations in hematological, biochemical, and immune parameters in body fluids following low-dose-rate radiation exposure in mice

Abstract

Purpose: Low-dose-rate (LDR) radiation is known to induce subtle biological effects, but its impact on body fluid-based biomarkers remains poorly defined. This study evaluated dose rate-dependent hematological, biochemical, and immunological changes in blood, peritoneal lavage fluid (PLF), and bronchoalveolar lavage fluid (BALF) in healthy mice.

Materials and methods: Mice were exposed to whole-body LDR radiation at 0.39, 1.29, or 3.46 mGy/h for 21 days. Hematological analysis was performed on blood, and PLF and BALF were analyzed for biochemical and immune cell parameters.

Results: Most hematological indices were stable, except in the 3.46 mGy/h group, which showed significant changes in reticulocytes, white blood cells, lymphocytes, and platelet-large cell ratio. In PLF, alkaline phosphatase isoenzyme fraction (ALPIF) increased at 0.39 mGy/h, while AST, CK, and lactate were elevated at 1.29 mGy/h but normalized at 3.46 mGy/h. Immune analysis revealed increased polymorphonuclear cells and reduced lymphocytes in PLF at 0.39 mGy/h, indicating localized immune activation. In contrast, BALF showed no significant biochemical or cellular changes. A cross-compartment comparison of ALT, AST, and CK revealed hepatic or muscular stress in blood at 0.39 mGy/h, and localized metabolic alterations in PLF at 1.29 mGy/h.

Conclusions: LDR radiation induces non-linear, dose rate-specific effects on immune and metabolic parameters in blood and PLF, while BALF responses remain minimal. These findings highlight the utility of fluid-based biomarkers for early, minimally invasive detection of radiation-induced changes.

Keywords: Body fluid; hematological parameters; low-dose-rate radiation; mouse; peritoneal lavage fluid.