Untitled

Abstract

The pharmacodynamic effect of ceftriaxone on smooth muscles was investigated in isolated organs. Maximum stimulation of isolated guinea pig's ileum, rabbit's duodenum and rat's fundic strip was achieved by addition of 1024 µg of ceftriaxone/ml bath. While in isolated rat's colon, it was achieved by 512 µg of ceftriaxone/ml bath. The effect of graded increased concentrations of ceftriaxone on isolated tracheal muscles and rat's uterine muscles was examined during estrus, non estrus, early pregnant and late pregnant stages. Trials were performed to locate the site of action of ceftriaxone on isolated smooth muscles. It was concluded that, ceftriaxone directly stimulates the smooth muscles of intestines; ceftriaxone in concentration of 1024 µg/ml bath has a serotonin like effect on rat's fundic strip and had a direct myometrial depressant effect. Ceftriaxone in all tested concentrations did not induce any effects on the resting tonus of isolated guinea pig's tracheal chain.