Data/hora: 06/06/2024 00:46:56

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Cyclosporin A preferentially attenuates skeletal slow-twitch muscle regeneration	
Autores: 	Miyabara,E.H.; Aoki,M.S.; Moriscot,A.S.	
Data: 	2005-04-01	
Ano: 	2005	
Palavras-chave: 	Calcineurin; Cyclosporin A; Regeneration; Fast and slow twitch muscles.	
Resumo: 	Calcineurin, a Ca2+/calmodulin-dependent phosphatase, is associated with muscle regeneration via NFATc1/GATA2-dependent pathways. However, it is not clear whether calcineurin preferentially affects the regeneration of slow- or fast-twitch muscles. We investigated the effect of a calcineurin inhibitor, cyclosporin A (CsA), on the morphology and fiber diameter of regenerating slow- and fast-twitch muscles. Adult Wistar rats (259.5 ± 9 g) maintained under standard conditions were treated with CsA (20 mg/kg body weight, ip) for 5 days, submitted to cryolesion of soleus and tibialis anterior (TA) muscles on the 6th day, and then treated with CsA for an additional 21 days. The muscles were removed, weighed, frozen, and stored in liquid nitrogen. Cryolesion did not alter the body weight gain of the animals after 21 days of regeneration (P = 0.001) and CsA significantly reduced the body weight gain (15.5%; P = 0.01) during the same period. All treated TA and soleus muscles showed decreased weights (17 and 29%, respectively, P &lt; 0.05). CsA treatment decreased the cross-sectional area of both soleus and TA muscles of cryoinjured animals (TA: 2108 ± 930 vs 792 ± 640 µm²; soleus: 2209 ± 322 vs 764 ± 439 m²; P &lt; 0.001). Histological sections of both muscles stained with Toluidine blue revealed similar regenerative responses after cryolesion. In addition, CsA was able to minimize these responses, i.e., centralized nuclei and split fibers, more efficiently so in TA muscle. These results indicate that calcineurin preferentially plays a role in regeneration of slow-twitch muscle.	
Tipo: 	Info:eu-repo/semantics/other	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000400009	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2005000400009	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.38 n.4 2005	
Fonte: 	info:eu-repo/semantics/openAccess