Abstract
The short-term cardiotoxic effects of gentamicin were studied on electrical and mechanical activities in cultures of ventricular confluent cardiocytes of rats. Application of gentamicin to the bath lowered the spontaneous action potential firing rate which was restored when the external calcium was elevated. Fast local application and withdrawal of drugs to non-pacemaker cells allowed effect/dose curves to be made. Such application of 200 nmol gentamicin (approximated concentration: 0.8 × 10 −3-8.0 × 10 −3 M) lowered the contraction amplitude by 50% and the action potential overshoot by 20% while the action potential duration and maximum diastolic potential remained unchanged. Gentamicin withdrawal was followed by a rapid (half time = 5 s) and complete restoration of contraction. Verapamil, Mn 2+, EDTA and La 3+ also diminished contraction and overshoot but their effects were reversed 28, 25, 6 and 1.5 times more slowly, respectively. Gentamicin, like La 3+, could act extracellularly, probably by competing with calcium ions for some external membrane site.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
