Abstract
We have studied calcium exchanges and mechanical function in heart muscle during and after a period of ischaemia. The experimental preparation was the isolated but arterially perfused interventricular septum of the rabbit. Uptake of calcium was measured with 47Ca2+ and efflux with 45Ca2+. 51Cr-EDTA was used as a marker of the extracellular space. Ischaemia caused a rapid decline of developed tension followed by a rise in resting tension. Tissue counts of 47Ca2+ decreased due to a reduction in the extracellular space. On reperfusion after ischaemia developed tension partially recovered and resting tension increased further before returning towards control values. A large and prolonged uptake of 47Ca2+ occurred immediately on reperfusion while 45Ca2+ efflux rose transiently. The uptake of calcium was related to the severity and duration of ischaemia and to the degree of mechanical recovery. Calcium accumulation on reperfusion is due to an increased influx which is not related to gross disruption of the cell membrane but more probably to a specific abnormality of ionic channels.
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.
