Statin-induced myotoxicity is exacerbated by aging: A biophysical and molecular biology study in rats treated with atorvastatin.
Toxicol Appl Pharmacol
; 306: 36-46, 2016 09 01.
Article
em En
| MEDLINE
| ID: mdl-27377005
ABSTRACT
Statin-induced skeletal muscle damage in rats is associated to the reduction of the resting sarcolemmal chloride conductance (gCl) and ClC-1 chloride channel expression. These drugs also affect the ClC-1 regulation by increasing protein kinase C (PKC) activity, which phosphorylate and close the channel. Also the intracellular resting calcium (restCa) level is increased. Similar alterations are observed in skeletal muscles of aged rats, suggesting a higher risk of statin myotoxicity. To verify this hypothesis, we performed a 4-5-weeks atorvastatin treatment of 24-months-old rats to evaluate the ClC-1 channel function by the two-intracellular microelectrodes technique as well as transcript and protein expression of different genes sensitive to statins by quantitative real-time-PCR and western blot analysis. The restCa was measured using FURA-2 imaging, and histological analysis of muscle sections was performed. The results show a marked reduction of resting gCl, in agreement with the reduced ClC-1 mRNA and protein expression in atorvastatin-treated aged rats, with respect to treated adult animals. The observed changes in myocyte-enhancer factor-2 (MEF2) expression may be involved in ClC-1 expression changes. The activity of PKC was also increased and further modulate the gCl in treated aged rats. In parallel, a marked reduction of the expression of glycolytic and mitochondrial enzymes demonstrates an impairment of muscle metabolism. No worsening of restCa or histological features was found in statin-treated aged animals. These findings suggest that a strong reduction of gCl and alteration of muscle metabolism coupled to muscle atrophy may contribute to the increased risk of statin-induced myopathy in the elderly.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Envelhecimento
/
Atrofia Muscular
/
Inibidores de Hidroximetilglutaril-CoA Redutases
/
Atorvastatina
Limite:
Animals
Idioma:
En
Revista:
Toxicol Appl Pharmacol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Itália