GS 283 is a compound with calcium antagonist and weak histamine and muscarinic receptor blocking activity, with activity in modulating contraction of guinea pig and rat tracheal smooth muscle. GS 283 inhibits contractions induced by carbachol, histamine (guinea pig only), and high H+ in guinea pig and rat tracheal smooth muscle, inhibits Ca2+-induced contractions in guinea pig tracheal smooth muscle, and at high concentrations completely abolishes contractions induced by carbachol in Ca2+-free medium.
