[Effects of taurine on tumor necrosis factor expression of lung in rats treated by silica].

OBJECTIVE

To evaluate the effects of taurine on the expression of tumor necrosis factor-alpha (TNF-alpha) protein of lung in rats treated by silica.

METHODS

144 Wistar rats were randomly divided into three experimental groups: saline-instilled with a control diet (saline-treated group), silica-instilled with a control diet (silica-treated group), and silica-instilled with a diet containing 2.5% taurine (taurine-treated group). There were 48 rats in every experimental group. Rats were treated by direct tracheal instillation of silica into rat lungs exposed surgically. 8 rats in every experimental group were killed at each at 6 time points (1, 3, 7, 14, 21 and 28 day) respectively. The taurine concentration of serum were analyzed by means of HPLC. The expression of TNF-alpha protein in paraffin-embedded lung sections with Streptavidin/ peroxidase(SP) immunohistochemistry on tissue microarray were measured by image-pro Plus.

RESULTS

The concentration of taurine in serum of taurine-treated group were significantly elevated when compared with saline-treated and silica-treated groups (P < 0.05, P < 0.01). After instillation of silica, TNF-alpha positive area percent of the lung was elevated in silica-treated rats when compared with the corresponding saline-treated group, peaking at 7 days, and elevated by 6.57% and 2.37% at 7 days and 14 days respectively (P < 0.01 or P < 0.05). Taurine treatment significantly decreased silica-elevated TNF-alpha positive area percent by 3.52 at 7 day (P < 0.05).

CONCLUSIONS

Treatment with taurine can effectively attenuate the pathological expression of TNF-alpha protein of lung in rats induced by silica.