Abstract

Ethylenediaminetetraacetic acid (EDTA) renders frog heart muscle fibers indiscriminately permeable to Na, K and S35O4 and causes relaxation of contractures induced by ouabain but has no effect on contractures induced by iodoacetate. The contracture induced by iodoacetate under anaerobic conditions can be reversed aerobically either in the presence or absence of EDTA. These observations indicate that the ouabain contracture is not due primarily to an intracellular shift in Na+ or K+ concentration nor to a gross interference with intracellular energy metabolism but could be due to an altered handling of Ca++ by the ouabain-treated muscle. A slightly greater than normal uptake of perfusate Ca45 was found to occur during ouabain contracture but not during exposure to concentrations of the drug causing only positive inotropic effects.

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 call

Disclaimer: 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.