Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 7 August 1981:
Vol. 213. no. 4508, pp. 663 - 666
DOI: 10.1126/science.7256266
Prev | Table of Contents | Next

Articles

Science, Vol 213, Issue 4508, 663-666
Copyright © 1981 by American Association for the Advancement of Science

articles

Intrinsic birefringence signal preceding the onset of contraction in heart muscle

R Weiss and M Morad

An intrinsic birefringence signal with two components occurring before sarcomere shortening was measured in mammalian cardiac muscle. The second component was sensitive to the inotropic state of the muscle as affected by external calcium concentration and epinephrine but not by changes of resting length. The second component was absent in frog heart. These results suggest that the second component of the birefringence signal reflects the activity of the sarcoplasmic reticulum related to excitation-contraction coupling processes occurring prior to onset of contraction in mammalian cardiac muscle.




To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)