Cardiac function of two ecologically distinct Neotropical freshwater fish: Curimbata, Prochilodus lineatus (Teleostei, Prochilodontidae), and trahira, Hoplias malabaricus (Teleostei, Erythrinidae)
| Autor: | Luciano Rivaroli, Ana Lúcia Kalinin, Francisco Tadeu Rantin |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Physiology
Prochilodontidae Heart Ventricles Zoology In Vitro Techniques Biochemistry Erythrinidae Acclimatization Cardiovascular Physiological Phenomena Hoplias malabaricus Isometric Contraction Extracellular Animals Ventricular Function Molecular Biology Ecosystem Teleostei biology Ryanodine Ecology Ryanodine receptor Fishes biology.organism_classification Myocardial Contraction Sarcoplasmic Reticulum Freshwater fish Calcium |
| Zdroj: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 145:322-327 |
| ISSN: | 1095-6433 |
| Popis: | An isometric muscle preparation was used to investigate the importance of the ventricular sarcoplasmic reticulum (SR) and extracellular Ca(2+) (2.5 up to 10.5 mM) to force generation at 25 degrees C (acclimation temperature) in two ecologically distinct Neotropical teleost fish: Curimbata (active species), and trahira (sedentary species). The post-rest force was studied with and without 10 muM ryanodine in the medium. The positive inotropism observed for both species in response to increases on extracellular Ca(2+) reflected a greater Ca(2+) influx through sarcolemma, as well as an increase in Ca(2+) liberation from the SR by the Ca(2+)-induced Ca(2+) release mechanism. The significant post-rest potentiation recorded for the curimbata and trahira control preparations (3.22+/-0.24 to 6.55+/-0.77 mN mm(-2) and 0.74+/-0.07 to 2.26+/-0.26 mN mm(-2), respectively), was completely inhibited by the addition of ryanodine to the bathing medium, suggesting a potential functionality of SR for both species. Considering the differences in these species habitats, modes of life and levels of activity and the fact of a probable SR Ca(2+) cycling in a physiological temperature, we suggest that the functionality of the SR in these species is probably related to their phylogeny. |
| Databáze: | OpenAIRE |
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