| Abstract: | The pharmacological action of cold aqueous extract of fresh leaves of Baphia nitida was studied on cardiac preparations. The extract (5.0 × 10?3 g mL) reduced the rate and force of contraction of the isolated rabbit heart. The rate and force of contraction of the spontaneously beating rat atria was dose-dependently reduced by 5.0 × 10?4 to 2.5 × 10?2 g/mL of the extract and this effect was not antagonized by 3.45 × 10?7 M atropine. The extract (5.0 × 10?2 g mL) completely blocked the positive chronotropic and inotropic effects of 10 mM CaCI2 but only reduced that of 1.61 × 10?7 M isoprenaline. The effect of the extract on CaCI2-induced responses of the rat atria was not affected by 3 × 10?7 M propranolol. The use of this extract for treating palpitation locally may be related to its negative chronotropic and inotropic effects. |
