Species difference in modulation of calcium release by Naja naja kaouthia snake venom cardiotoxin in terminal cisternae from human and equine skeletal muscle.
Abstract: The modulation of Ca2+ release by a cardiotoxin (CTX) from Naja naja kaouthia snake venom was examined in terminal cisternae-containing fractions from equine and human skeletal muscle. Pretreatment with CTX (10 microM) decreased by 27% (human muscle), or had no effect on (equine muscle), the threshold of Ca(2+)-induced Ca2+ release. If terminal cisternae fractions were first preloaded with Ca2+ to greater than 65% of the threshold of Ca(2+)-induced Ca2+ release and then CTX added, an immediate and sustained release of Ca2+ occurred in preparations from both species. Addition of CTX after a Ca2+ preload of less than 60% of the threshold of Ca(2+)-induced Ca2+ release did not elicit Ca2+ release in preparations from either species. Ruthenium red (10 microM) antagonized CTX-induced Ca2+ release, whereas dantrolene (10 microM) did not. These findings suggest that the effects of CTX on the Ca2+ release channel are dependent on Ca2+ preload and that CTX may be an important probe of the Ca(2+)-modulated Ca2+ release process and in understanding regulation of Ca2+ release in skeletal muscle from different species.
Publication Date: 1993-01-01 PubMed ID: 8446962DOI: 10.1016/0041-0101(93)90355-mGoogle Scholar: Lookup
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- Journal Article
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
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The research article investigates how a toxin (CTX) from the venom of the Naja naja kaouthia snake affects the release of calcium in skeletal muscle cells of humans and horses. The findings indicate that the toxin’s effects differ depending on the species and the initial calcium levels in the cells.
Study Methodology and Evaluation of CTX’s Effects
- The study focused on the action of a cardiotoxin (CTX) extracted from the venom of Naja naja kaouthia snake.
- This CTX was tested on skeletal muscle cells from humans and horses. Specifically, skeletal muscle cells containing terminal cisternae were used. Terminal cisternae are specialized regions in muscle cells where calcium is stored and released.
- The threshold for calcium-induced calcium release (CICR) was evaluated both before and after the introduction of CTX.
Findings on CTX’s Effects
- The research found that the effects of CTX on calcium release depend on the initial amount of calcium, or ‘preload’, in the cells.
- In the case of human muscle cells, CTX decreased the CICR threshold by 27%. In other words, less calcium was needed to trigger the release of more calcium within the cells.
- In the equine muscle cells, CTX had no effect on the baseline calcium release threshold.
- Interestingly, if the muscle cells were preloaded with calcium levels at 65% or more of the CICR threshold and then exposed to CTX, an immediate and continuous release of calcium occurred in samples from both species.
- Yet, if the cells had a calcium preload below 60%, CTX did not stimulate calcium release in either species.
Implications and Potential Uses of CTX
- The results suggest that ruthenium red, a substance that can inhibit calcium release, was able to block the effects of CTX. However, dantrolene, another substance that impacts calcium release, had no effect on CTX-induced calcium release.
- These results highlight that the effects of CTX are closely tied to the initial calcium levels within the cells and the species from which the cells originate.
- The study furthers the understanding of calcium release regulation in skeletal muscle and suggests that CTX could be a useful tool for probing these processes.
Cite This Article
APA
Fletcher JE, Tripolitis L, Beech J.
(1993).
Species difference in modulation of calcium release by Naja naja kaouthia snake venom cardiotoxin in terminal cisternae from human and equine skeletal muscle.
Toxicon, 31(1), 43-51.
https://doi.org/10.1016/0041-0101(93)90355-m Publication
Researcher Affiliations
- Department of Anesthesiology, Hahnemann University, Philadelphia, PA 19102-1192.
MeSH Terms
- Animals
- Calcium / metabolism
- Cobra Cardiotoxin Proteins / toxicity
- Dantrolene / pharmacology
- Horses
- In Vitro Techniques
- Muscle Contraction / drug effects
- Muscles / metabolism
- Sarcoplasmic Reticulum / metabolism
- Species Specificity
- Swine
Citations
This article has been cited 2 times.- Averin AS, Nenov MN, Starkov VG, Tsetlin VI, Utkin YN. Effects of Cardiotoxins from Naja oxiana Cobra Venom on Rat Heart Muscle and Aorta: A Comparative Study of Toxin-Induced Contraction Mechanisms.. Toxins (Basel) 2022 Jan 24;14(2).
- Subbaiah CC, Zhang J, Sachs MM. Involvement of intracellular calcium in anaerobic gene expression and survival of maize seedlings.. Plant Physiol 1994 May;105(1):369-76.
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