Caffeine contractures, twitch characteristics and the threshold for Ca(2+)-induced Ca2+ release in skeletal muscle from horses with chronic intermittent rhabdomyolysis.
Abstract: Muscle from horses with intermittent exercise associated rhabdomyolysis was examined to determine if calcium regulation was abnormal. In vitro studies on semimembranosus muscle fibre bundles showed the time to 50 per cent relaxation of caffeine-induced contractures was shorter and the electrically elicited twitch longer in horses with exercise associated rhabdomyolysis. Substitution of strontium for calcium eliminated the difference in caffeine contracture between the normal and rhabdomyolysis horses. The threshold of calcium-induced calcium release was lower than normal in terminal cisternae-containing fractions of muscle from horses with rhabdomyolysis. Thoroughbreds with rhabdomyolysis had a shorter time to peak twitch tension than standardbreds, and normal thoroughbreds had a shorter caffeine contracture than normal standardbreds. There was no difference in fibre typing between breeds or groups. Either no histological changes or low grade to moderate degenerative myopathy was seen in muscle from horses with rhabdomyolysis. These results suggest horses with intermittent exercise associated rhabdomyolysis have abnormal calcium regulation.
Publication Date: 1993-01-01 PubMed ID: 8434138DOI: 10.1016/0034-5288(93)90019-cGoogle Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research explores the connection between chronic intermittent rhabdomyolysis in horses with abnormal calcium regulation. The study finds that horses with exercise-related rhabdomyolysis not only have an altered response to caffeine-induced muscle contractions, but they also have different twitch characteristics and a lower threshold for calcium-induced calcium release.
Methodology
- The study focused on examining muscle from horses with intermittent exercise-associated rhabdomyolysis, particularly seeking abnormalities in calcium regulation. The semimembranosus muscle fibre bundles were studied in vitro.
- The study also investigated the response of these horses to caffeine-induced contractures, changes in the duration of electrically elicited twitches, and the effects of substituting strontium for calcium.
- Examinations were made across different horse breeds including Thoroughbreds and Standardbreds.
- In addition to these, the threshold for calcium-induced calcium release in terminal cisternae-containing fractions of muscles from horses with rhabdomyolysis was also studied.
Findings
- Findings from the study reveal that the time to reach a 50% relaxation of caffeine-induced contractures was shorter in horses with exercise-related rhabdomyolysis. Additionally, these horses experienced a longer duration for electrically elicited twitches.
- Replacing calcium with strontium eliminated the difference in caffeine contracture between the normal horses and those with rhabdomyolysis. This indicates that calcium is a significant factor in the physical abnormalities presented by horses with rhabdomyolysis.
- In muscle segments containing terminal cisternae, the threshold at which calcium induces calcium release was found to be lower than normal in horses with rhabdomyolysis, suggesting a higher sensitivity or reactivity to calcium.
- Thoroughbreds with rhabdomyolysis had a shorter time to reach peak twitch tension compared to healthy Standardbred horses. This points to breed-specific differences in muscle response.
- Fibre typing – a molecular technique used to differentiate various types of muscle fibres – did not yield any notable differences between the breeds or groups studied.
- No significant histological changes were observed in the muscle from horses with rhabdomyolysis. Low grade to moderate degenerative myopathy – a type of muscular disease – was reported in a few cases.
Conclusion
- The results of the research suggest that horses with intermittent exercise-associated rhabdomyolysis may have abnormalities in calcium regulation.
- This can lead to differences in muscle contractions and twitch characteristic as well as a reduced threshold for calcium-induced calcium release.
- The use of different horse breeds in the study indicates that findings may be applicable across various breeds, potentially guiding future preventative and treatment strategies for rhabdomyolysis in the wider horse population.
Cite This Article
APA
Beech J, Lindborg S, Fletcher JE, Lizzo F, Tripolitis L, Braund K.
(1993).
Caffeine contractures, twitch characteristics and the threshold for Ca(2+)-induced Ca2+ release in skeletal muscle from horses with chronic intermittent rhabdomyolysis.
Res Vet Sci, 54(1), 110-117.
https://doi.org/10.1016/0034-5288(93)90019-c Publication
Researcher Affiliations
- Department of Clinical Studies, University of Pennsylvania, School of Veterinary Medicine, Kennett Square 19348.
MeSH Terms
- Animals
- Caffeine / pharmacology
- Calcium / metabolism
- Calcium / physiology
- Female
- Halothane / pharmacology
- Horse Diseases / pathology
- Horse Diseases / physiopathology
- Horses
- In Vitro Techniques
- Male
- Muscle Contraction / drug effects
- Muscles / drug effects
- Muscles / physiopathology
- Rhabdomyolysis / pathology
- Rhabdomyolysis / physiopathology
- Rhabdomyolysis / veterinary
Citations
This article has been cited 7 times.- Valberg SJ, Velez-Irizarry D, Williams ZJ, Henry ML, Iglewski H, Herrick K, Fenger C. Enriched Pathways of Calcium Regulation, Cellular/Oxidative Stress, Inflammation, and Cell Proliferation Characterize Gluteal Muscle of Standardbred Horses between Episodes of Recurrent Exertional Rhabdomyolysis. Genes (Basel) 2022 Oct 14;13(10).
- Autry JM, Svensson B, Carlson SF, Chen Z, Cornea RL, Thomas DD, Valberg SJ. Sarcoplasmic Reticulum from Horse Gluteal Muscle Is Poised for Enhanced Calcium Transport. Vet Sci 2021 Nov 23;8(12).
- Aldrich K, Velez-Irizarry D, Fenger C, Schott M, Valberg SJ. Pathways of calcium regulation, electron transport, and mitochondrial protein translation are molecular signatures of susceptibility to recurrent exertional rhabdomyolysis in Thoroughbred racehorses. PLoS One 2021;16(2):e0244556.
- Autry JM, Karim CB, Cocco M, Carlson SF, Thomas DD, Valberg SJ. Purification of sarcoplasmic reticulum vesicles from horse gluteal muscle. Anal Biochem 2020 Dec 1;610:113965.
- Valberg SJ, Soave K, Williams ZJ, Perumbakkam S, Schott M, Finno CJ, Petersen JL, Fenger C, Autry JM, Thomas DD. Coding sequences of sarcoplasmic reticulum calcium ATPase regulatory peptides and expression of calcium regulatory genes in recurrent exertional rhabdomyolysis. J Vet Intern Med 2019 Mar;33(2):933-941.
- Isgren CM, Upjohn MM, Fernandez-Fuente M, Massey C, Pollott G, Verheyen KL, Piercy RJ. Epidemiology of exertional rhabdomyolysis susceptibility in standardbred horses reveals associated risk factors and underlying enhanced performance. PLoS One 2010 Jul 14;5(7):e11594.
- López JR, Linares N, Cordovez G, Terzic A. Elevated myoplasmic calcium in exercise-induced equine rhabdomyolysis. Pflugers Arch 1995 Jun;430(2):293-5.
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