Abstract
Effects of some kinds of antibotics on the electrical and mechanical activities of guinea-pig taenia coli were investigated. The sucrose gap method was used for measurement of electrical activity and simultaneously isometric tension was recorded. Both cephalothin (2.4mM) and lincomycin (2.2mM) did not cause any effect on the spontaneous electrical and mechanical activities. Chloramphenicol (3.1mM) completely abolished the spontaneous spike discharges and relaxed the smooth muscle in a short time, while clindamycin (2.2mM) took a long time to produce an effect as same as chloramphenicol. Both chloramphenicol and clindamycin abolished the stimuls-induced spkies and Sr-spikes. All of these responses were reversible by washing out with normal Krebs solution.
These results suggest that chloramphenicol and clindamycin may inhibit Ca2+ influx through the Ca2+ channels across the smooth muscle cell membrane.
