AJP - Regu Watch the video to learn how APS reaches out to developing nations.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 257: R599-R604, 1989;
0363-6119/89 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by el-Sayed, M. F.
Right arrow Articles by Gesser, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by el-Sayed, M. F.
Right arrow Articles by Gesser, H.

AJP - Regulatory, Integrative and Comparative Physiology, Vol 257, Issue 3 599-R604, Copyright © 1989 by American Physiological Society

ARTICLES

Sarcoplasmic reticulum, potassium, and cardiac force in rainbow trout and plaice

M. F. el-Sayed and H. Gesser
Department of Zoophysiology, University of Aarhus, Denmark.

The role played by the sarcoplasmic reticulum in force development and in cellular Ca2+ balance and its dependence on extracellular K+ were examined in heart ventricular tissue of rainbow trout and plaice. Compared with the steady-state twitch at a stimulation rate of 0.2 Hz, a 30-s rest led to a similar increase in twitch force in trout heart, regardless of whether [K+] was 2.5 or 5 mM. At 5 mM (but not at 2.5 mM) post-rest potentiation increased with increasing rest periods (from 30 to 900 s). These post-rest potentiations were removed or transformed into a loss of force by 10 microM ryanodine or 8 mM caffeine. In the plaice heart, where the sarcoplasmic reticulum is claimed to be sparse, the post-rest potentiation and the influence of ryanodine were small. The Ca2+ uptake measured during 5 min with 45Ca in the trout heart was higher in 5 than in 2.5 mM K+, regardless of the concomitant stimulation rate. This effect of K+ was removed by 10 microM ryanodine. The twitch force after 5 min of rest correlated significantly with the Ca2+ uptake, whereas the twitch force developed at a rate of 0.2 or 1.0 Hz did not. In conclusion, an elevation of K+ appears to stimulate the Ca2+ uptake of the sarcoplasmic reticulum. The twitch force after prolonged rest seems to relate to the Ca2+ contained in this organelle, whereas this does not apply to the twitch force developed at more physiological rates (0.2 or 1 Hz).


This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
P. K. Battiprolu, K. J. Harmon, and K. J. Rodnick
Sex differences in energy metabolism and performance of teleost cardiac tissue
Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2007; 292(2): R827 - R836.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
A. Chugun, K. Taniguchi, T. Murayama, T. Uchide, Y. Hara, K. Temma, Y. Ogawa, and T. Akera
Subcellular distribution of ryanodine receptors in the cardiac muscle of carp (Cyprinus carpio)
Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2003; 285(3): R601 - R609.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
L. Hove-Madsen and L. Tort
L-type Ca2+ current and excitation-contraction coupling in single atrial myocytes from rainbow trout
Am J Physiol Regulatory Integrative Comp Physiol, December 1, 1998; 275(6): R2061 - R2069.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
L. Hove-Madsen, A. Llach, and L. Tort
Quantification of Ca2+ uptake in the sarcoplasmic reticulum of trout ventricular myocytes
Am J Physiol Regulatory Integrative Comp Physiol, December 1, 1998; 275(6): R2070 - R2080.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online