Histopathological effects of electric welding fumes on liver in Rats

Increasing daily development of industry is intimately associated with obligatory use of electric welding process in light and heavy industrial companies. Recent studies showed some deleterious effects of welding fumes generated during electric welding on human bodies in circulatory, blood, gastrointestinal, respiratory and reproductive systems. The aim of the present study was to define the histopathological effects of welding fumes on liver cells and its enzymes in a conditioned medium in gas exposure chamber in Rat as an experimental model. Methods and Materials: A total number of 60 Sprague Dawley Rats were chosen and divided into experimental (40) and control (20) groups. Each group was subdivided into 2, 4, 6 and 8-week subgroups. The number of Rat in each subgroup of experimental and control group was 10 and 5, respectively. Experimental group Rats were exposed to fumes of electric welding for 2 hour/day and 5 day/week. The rate of air turn over in exposure chamber was fixed to 12-15/hour. The amount of O3, CO, CO2, NO + NO2 and particulate matter were measured by Galtec detectors and Cellulose acetate filter, respectively. According to timetable animals were killed and specimens from liver and blood were taken, tissue specimens fixed in formaline buffer solution and processed routinely. Sections with 5-7 micrometer in thickness were stained by H-E, PAS, PNA, WGA and Alcian blue pH=2.5. The enzyme activity was measured and data were analyzed by Kruskall Wallis and Mann Whiney NPAR tests. The results of this study showed the presence of small quantities of Gal/GalNac in the sub endothelial connective tissue of central venule and also sialic acid and GluNac in endothelial cells of sinusoid in liver. PAS staining showed that the amount of glycogen particle in hepatocyte changed in experimental group especially in peripheral cells of classic lobule. Statistical analysis showed that there was no any statistically significant difference for alkaline phosphatase, ALT and AST between all studied groups. It seems that hepatocytes and its own serum enzyme activity changes are time dependent after exposure to welding fumes. The future studies will probably showed the exact role of these fumes in hepatocyte and its relation to pathophysiology of liver diseases.