Impact of alpha-tocopherol deficiency and supplementation on sacrocaudalis and gluteal muscle fiber histopathology and morphology in horses.
J Vet Intern Med
; 33(6): 2770-2779, 2019 Nov.
Article
em En
| MEDLINE
| ID: mdl-31660648
ABSTRACT
BACKGROUND:
A subset of horses deficient in alpha-tocopherol (α-TP) develop muscle atrophy and vitamin E-responsive myopathy (VEM) characterized by mitochondrial alterations in the sacrocaudalis dorsalis medialis muscle (SC).OBJECTIVES:
To quantify muscle histopathologic abnormalities in subclinical α-TP deficient horses before and after α-TP supplementation and compare with retrospective (r)VEM cases. ANIMALS Prospective study; 16 healthy α-TP-deficient Quarter Horses. Retrospective study; 10 retrospective vitamin E-responsive myopathy (rVEM) cases .METHODS:
Blood, SC, and gluteus medius (GM) biopsy specimens were obtained before (day 0) and 56 days after 5000 IU/450 kg horse/day PO water dispersible liquid α-TP (n = 8) or control (n = 8). Muscle fiber morphology and mitochondrial alterations were compared in samples from days 0 and 56 and in rVEM cases.RESULTS:
Mitochondrial alterations more common than our reference range (<2.5% affected fibers) were present in 3/8 control and 4/8 treatment horses on day 0 in SC but not in GM (mean, 2.2; range, 0%-10% of fibers). Supplementation with α-TP for 56 days did not change the percentage of fibers with mitochondrial alterations or anguloid atrophy, or fiber size in GM or SC. Clinical rVEM horses had significantly more mitochondrial alterations (rVEM SC, 13% ± 7%; GM, 3% ± 2%) and anguloid atrophy compared to subclinical day 0 horses. CONCLUSIONS AND CLINICAL IMPORTANCE Clinically normal α-TP-deficient horses can have mitochondrial alterations in the SC that are less severe than in atrophied VEM cases and do not resolve after 56 days of α-TP supplementation. Preventing α-TP deficiency may be of long-term importance for mitochondrial viability.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Deficiência de Vitamina E
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Alfa-Tocoferol
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Doenças dos Cavalos
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Doenças Musculares
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article