[Effects of tetramethylpyrazine and ferulic acid alone or combined on vascular smooth muscle, blood viscosity and toxicity].

ABSTRACT

The experiments showed that both tetramethylpyrazine and ferulic acid relaxed the norepinephrine-induced spasmodic contraction of rabbit and rat aorta strips, increased the coronary flow of isolated guinea pig hearts and reduced the whole blood viscosity in rats. Evaluated with Burgi's equation, the combined effect of these 2 drugs was obviously potentiated, but the combined acute toxicity in mice was greatly reduced.