Cell Signal Transduction Pathway On Rat Vasodilatation Caused By Sulfur Dioxide Derivatives

Sulfur dioxide, as a major air pollutant, has been paid more and more attention to its toxic effect. Recently, many studies have indicated that SO₂ is a system toxin, and inhalation SO₂ or celiac injection SO₂ derivatives on rat lead to lower significantly blood pressure. In this study, the pathway and mechanism on lowering the blood pressure of SO₂ and its derivatives were studied in the following aspects:1. The effect of SO₂ derivatives on the changes of PGI2 and TXA₂ in the plasma and vessel of rats6-Keto-PGF_1a and TXB₂ were determined by radioimmunoassay in the plasma and aorta tissue. A significant increase of 6-Keto level in the isolated aortic rings appeared at all concentrations tested except 8mmol/L. No change of TXB₂ level was observed in the rings at all concentrations tested. Meanwhile, 6-Keto/TXB₂ ratios were increased at 2mmol/L and 4mmol/L significantly. Compared with control group, 6-Keto level was significantly decreased in plasma of the rats which were exposured to SO₂ at 14 mg/m³ . 28mg/m³ and 56mg/m³, but there was a distinct increase of TXB₂ level. 6-Keto/TXB² ratio was decreased gradually with the increase of SO₂ concentration. Mechanism of lowering blood pressure of SO₂ derivatives on...