|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Differences in Force-Frequency Relationships and Calcium Dependency Between Elasmobranch and Teleost Hearts
1 Biology Department, Mount Allison University, Sackville, NB, Canada EOA 3C0, Huntsman Marine Laboratory St Andrews, NB, Canada EOG 2X0
2 Department of Zoophysiology, University of Aarhus, DK-8000, Aarhus C, Denmark and Huntsman Marine Laboratory St Andrews, NB, Canada EOG 2X0
Ventricle strips from little skate (Raja erinacea), spiny dogfish (Squalus acanthias), black dogfish (Etmopterus spinax), sea raven (Hemitripterus americanus), cod (Gadus morhua), hagfish (Myxine glutinosa) and white sturgeon (Acipenser transmontanus) were mounted for isometric force recording. Force development was assessed as a function of external calcium concentration and frequency of contraction. Post-rest potentiation was determined in skate and the teleost species to assess indirectly calcium storage capacities. Sea raven and cod preparations were also treated with ryanodine to assess the importance of calcium release from the sarcoplasmic reticulum.
Ventricle strips from skate and black dogfish showed a five-fold increase in force development when external calcium was raised from a physiological to a saturating level. Force development by ventricle strips from other species tested increased by only about 50% over the same range of calcium concentration.
For all elasmobranchs tested, an elevation in frequency of contraction of ventricle strips resulted first in an increase and subsequently in a decrease in force development. The apices of the curves were well within the physiological range of heart rates exhibited by these species. Preparations from teleosts showed only a decrease in force development when contraction frequency was elevated.
Skate ventricle strips exhibited a very marked post-rest potentiation at 3mmoll-1 external calcium. This protocol is considered to reflect the importance of intracellular calcium stores in the beat-to-beat maintenance of contractility. Sea raven and cod ventricle strips did not show any major post-rest potentiation, suggesting that calcium storage in hearts of these species is minimal. Ryanodine treatment had no effect upon sea raven and cod heart preparations. This approach further implies that calcium release from sarcoplasmic reticulum is not critical in these species.
Key words: calcium sensitivity, elasmobranch hearts, force-frequency, post-rest potentiation, ryanodine, teleost hearts
Accepted on February 29, 1988
This article has been cited by other articles:
|
|
 |
|
  G. L. J. Galli, E. W. Taylor, and H. A. Shiels Calcium flux in turtle ventricular myocytes Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2006; 291(6): R1781 - R1789. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Chatelier, N. Imbert, J. L. Z. Infante, D. J. McKenzie, and P. Bois Effects of oleic acid on the high threshold barium current in seabass Dicentrarchus labrax ventricular myocytes J. Exp. Biol., October 15, 2006; 209(20): 4033 - 4039. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. S. Farrar, P. K. Battiprolu, N. S. Pierson, and K. J. Rodnick Steroid-induced cardiac contractility requires exogenous glucose, glycolysis and the sarcoplasmic reticulum in rainbow trout J. Exp. Biol., June 1, 2006; 209(11): 2114 - 2128. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. L. J. Galli, H. Gesser, E. W. Taylor, H. A. Shiels, and T. Wang The role of the sarcoplasmic reticulum in the generation of high heart rates and blood pressures in reptiles J. Exp. Biol., May 15, 2006; 209(10): 1956 - 1963. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Landeira-Fernandez, J. M. Morrissette, J. M. Blank, and B. A. Block Temperature dependence of the Ca2+-ATPase (SERCA2) in the ventricles of tuna and mackerel Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2004; 286(2): R398 - R404. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Harwood, I. S. Young, and J. D. Altringham How the efficiency of rainbow trout (Oncorhynchus mykiss) ventricular muscle changes with cycle frequency J. Exp. Biol., March 1, 2002; 205(5): 697 - 706. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Uesaka, K. Yano, S. Sugimoto, and M. Ando Glucagon-like peptide isolated from the eel intestine: effects on atrial beating J. Exp. Biol., January 9, 2001; 204(17): 3019 - 3026. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. Kim, M. D. Coyne, and J. K. Gwathmey Voltage-dependent calcium channels in ventricular cells of rainbow trout: effect of temperature changes in vitro Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2000; 278(6): R1524 - R1534. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. Coyne, C. S. Kim, J. S. Cameron, and J. K. Gwathmey Effects of temperature and calcium availability on ventricular myocardium from rainbow trout Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2000; 278(6): R1535 - R1544. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Harwood, F. Howarth, J. Altringham, and E White Rate-dependent changes in cell shortening, intracellular Ca(2+) levels and membrane potential in single, isolated rainbow trout (Oncorhynchus mykiss) ventricular myocytes J. Exp. Biol., January 2, 2000; 203(3): 493 - 504. [Abstract] [PDF]
|
|
|
|
|
|
J Altimiras, L Hove-Madsen, and H Gesser Ca(2+) uptake in the sarcoplasmic reticulum from the systemic heart of octopod cephalopods J. Exp. Biol., January 9, 1999; 202(18): 2531 - 2537. [Abstract] [PDF]
|
|
|
|
|
|
M Vornanen Na+/Ca2+ exchange current in ventricular myocytes of fish heart: contribution to sarcolemmal Ca2+ influx J. Exp. Biol., January 7, 1999; 202(13): 1763 - 1775. [Abstract] [PDF]
|
|
|
|
|
|
H. Shiels, E. Freund, A. Farrell, and B. Block The sarcoplasmic reticulum plays a major role in isometric contraction in atrial muscle of yellowfin tuna J. Exp. Biol., January 4, 1999; 202(7): 881 - 890. [Abstract] [PDF]
|
|
