Subacute Immunotoxicity Study of Formaldehyde in Male Rats

Abstract

Immune functions were examined in male rats following 28 day oral administration of formaldehyde by gastric tube at dose levels of 0, 20, 40, and 80 mg/kg. Routine parameters examined included hematology, clinical chemistry, and body, thymus, kidney, and liver weights. In addition, cellularity of spleen and lymph nodes, histology of spleen, thymus, lymph nodes, liver kidney, small and large intestines, and histochemistry of spleen and lymph nodes were evaluated. Immune parameters evaluated included serum hemagglutinin antibody response; antibody plaque forming cell response to sheep erythrocytes (lymphocyte-dependent antigen); microbicidal activity of Candida albicans; and phagocytic activity by adhesion of microspheric hydrophilic synthetic particles to leukocyte cell membrane. Body weights were slightly decreased at high dose level (80 mg/kg). The difference was significant when compared to the controls. The lymph node weights were significantly increased in rats receiving formaldehyde. The cellularity of lymphoid organs was not influenced after 28 day exposure to formaldehyde.

Hemato-immunologic impact of subchronic exposure to melamine and/or formaldehyde in mice

“…These results are partly in agreement with those of a study wherein FA inhalation (5-10 ppm, 4 weeks) led to significantly increased serum IgM and decreased serum IgG levels in rats (Sapmaz et al 2015). However, Vargova et al (1993) reported that oral administration of FA for 28 days reduced the levels of both IgG and IgM in rats. Such contradictory outcomes are not unique to rodent models.…”

“…In non-ingestible settings, FA is broadly used in the production of foam insulation, carpeting, and pressed-wood products (Maddalena et al 2009). Regardless of its widespread use, FA has been described as a toxicant to the respiratory tract, as well as the nervous and urogenital systems (Vargova et al 1993;Zararsiz et al 2006). FA is frequently used in combination with MA in the manufacture of thermosetting plastics including those used in kitchenware, whiteboards, and commercial filters; both are also used as flame retardants in buses and aircraft (Ibhazehiebo & Koibuchi 2012).…”

“…FA is routinely added as a preservative for foods (e.g. Fruits, vegetables, seafood, and honey) and some drugs (Vargova et al 1993). FA is also used to reduce bacterial load (especially Salmonella) in poultry feed (Brown 1996).…”

Effects of Xylene and Formaldehyde Inhalations on Oxidative Stress in Adult and Developing Rats Livers

“…A significant decrease in total body weight and in selected target organ weights of experimental animals is usually considered to be an indicator of general toxicity following chemical exposure [45]. It was reported previously that body and liver weights decreased, high dose/short-term [3] or low dose/long-term, after exposure to HCHO [35].…”

“…In addition, body and liver weights were determined in order to find out the effects of xylene and HCHO on growth performance in adult and developing rats. Blood concentrations of xylene and HCHO were not detected in rats exposed to xylene and HCHO through inhalation, because of rapid metabolism and clearance from plasma [11,12,22,36,45]. Thus, no examination was performed for histochemical changes.…”