The antispasmodic activity of baicalin on isolated smooth muscle of guinea pig distal colon

The effects of baicalin ( the dry root extract of Scutellaria baicalensis Georgi ) on the isolated smooth muscle of the guinea pig colon and their possible mechanisms were investigated. The isolated organ method was adopted. The efficacy was recorded and analyzed by biological signal collection and analysis recording. Baicalin inhibited the spontaneous contraction of guinea pig colon, and antagonized the contractions of the isolated guinea pig colon induced by BaCl2 (2 mg/ml), KCl (60 mM), and acetylcholine (10 -5 M) in a manner that was concentration-dependent. The relaxant response of baicalin to BaCl2 was not related to adrenergic receptors, K + channels or PG, but the contraction induced by CaCl2 (10 -5 M to 3×10 -2 M) was inhibited by baicalin. The effect of baicalin, like verapamil (10 -7 Mol/L), is related its effect on potential-dependent calcium channels.