Evaluation of immunotoxicity of sodium metavanadate following drinking water exposure in female B6C3F1/N mice in a 28‐day study

Abstract

Sodium metavanadate (NaVO3) is a pentavalent vanadium compound used in the metal industry and dietary supplements; human exposure occurs through inhalation of fumes and dust and ingestion of NaVO3‐containing products. The objective of this study was to assess the potential immunotoxicity of NaVO3. Female B6C3F1/N mice were exposed to 0–500 ppm NaVO3 in drinking water for 28 days and evaluated for effects on immune cell populations and innate, cellular‐mediated, and humoral‐mediated immunity. There was a decreasing trend in body weight (BW) and BW gain in NaVO3 exposed mice, with a decrease (p ≤ 0.05) in BW gain at ≥250 ppm, relative to control. Conversely, increasing trends in spleen weights and an increase (p ≤ 0.05) in the spleen:BW ratio at ≥250 ppm NaVO3 were observed. NaVO3 exposure altered antibody production against sheep red blood cells (SRBC). Antibody forming cells (AFC)/106 spleen cells exhibited a decreasing trend, with a decrease (p ≤ 0.05) at 500 ppm NaVO3, concurrent with an increase in percent B cells. NaVO3 had no effect on the serum anti‐SRBC IgM antibody titers or anti‐keyhole limpet hemocyanin antibody production. Exposure to NaVO3 decreased the percentage of natural killer cells at all dose levels (p ≤ 0.05), with no effect on the lytic activity. NaVO3 altered T‐cell populations at 500 ppm but had no effect on T‐cell proliferative responses or the lytic activity of cytotoxic T cells. Collectively, these data indicate that NaVO3 exposure can adversely affect the immune system by inducing alterations in humoral‐mediated immunity, specifically the AFC response, with no effect on cell‐mediated or innate immunity.