EFFECT OF SPECTINOMYCIN ON ISOLATED SMOOTH AND CARDIAC MUSCLES AND NEUROMUSCULAR JUNCTIONS

Elsayed, M.G.; Elkomy, A.A and Mona, T. Hasseeb

Abstract

The pharmacodynamic effects of spectinomycin on smooth muscles were investigated in isolated organs (gastrointestinal, cardiovascular, uterine and tracheal smooth muscles). As the effect of graded increased concentrations of spectinomycin on isolated smooth muscles showed inhibitory effect. Spectinomycin in the tested concentrations produced a dose-dependent negative inotropic effect on isolated rabbit's heart and guinea pig's auricles. Spectinomycin in all tested concentrations did not induce any effects on the isolated guinea pig's tracheal chain and rabbit's aortic strips. Neuromuscular blockade effect of spectinomycin was investigated on isolated frog's gastrocnemius muscles and rectus abdominis muscle preparations. It was concluded that, spectinomycin directly inhibited smooth muscles of gastrointestinal tract and depressed those of uterus in various stages of sex cycle as well as cardiac muscle. Spectinomycin might act directly to induce neuromuscular blockade. It was concluded that spectinomycin scarcely any pharmacological properties which might be lead to severe adverse reaction in clinical use.

Key words

Cardiac muscles, neuromuscular junctions, smooth muscles, spectinomycin.