Volatile of alkyd varnish inhibits the expression of neuronal growth associated protein-43 in mice

Abstract

Background Studies have demonstrated that coating materials used commonly in the interior decoration contain volatile of alkyd varnish, which has obvious effects on the structure of endothelial cells of respiratory tract. Objective To observe the effects of volatile of alkyd varnish in the decoration materials on the expression of neuronal growth associated protein-43 (GAP-43) in mice, and to analyze the influencing mechanism of interior environmental pollutants for brain mechanism. Design A randomized grouping and controlled experiment. Setting College of Life Science, Liaoning Normal University. Materials This study was carried out in the College of Life Science, Liaoning Normal University between February and December 2006. Twenty one-month-old Kunming mice, weighing (20±2)g, male and female in half, were involved in this study. The involved mice were divided into 2 groups by random lot method: chronic poisoning group ( n =10) and control group ( n =10). Alkyd varnish used commonly for house decoration was purchased from Furnishing World of Liberation Plaza of Dalian City. Alkyd varnish used commonly for house decoration was purchased from Furnishing World of Liberation Plaza of Dalian City. Rabbit GAP-43 polyclonal antibody, ratβ-actin monoclonal antibody, goat anti-rat IgG-HRP and goat ant-rabbit IgG-HRP were purchased from Boster Company (Wuhan). ECL was purchased from Amersham Company (Britain), other related reagents were all purchased from Sigma Company and Promega Company (USA). All the other reagents were home-made analytical pure. Methods ▪Poisoning test The mice were poisoned by static inhalation poisoning method. Mice in the chronic poisoning group were placed in the 0.024 m 3 poisoning cabinet. Alkyd varnish (8 g, 3-time dosage of house decoration) was daily spread once on a 40 cm×21 cm kraft paper evenly. Mice were poisoned for 14 hours within 3 weeks successively. Mice in the control group were placed in the same environment without alkyd varnish, and the poisoning method was the same as that of chronic poisoning group. ▪Experimental evaluation: content of protein in the cortex, cerebellum and hippocampus of mice was measured separately by Bradford method. GAP-43 expression in the hippocampus and cortex was observed separately by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Main Outcome Measures Content of protein and expression of GAP-43 in different brain regions of mice. Results Twenty mice were involved in the final analysis. ▪Content of protein in the cerebellum and hippocampus of mice in the chronic poisoning group was decreased a little, separately ( P > 0.05). ▪ GAP-43 expression in the hippocampus of mice of the chronic poisoning group was significantly lower than that of the control group( P < 0.05). Conclusion Long-term action of volatile of alkyd varnish can inhibit the brain functions of mice by depressing the GAP-43 expression in hippocampus of mice.