Hypertrophied myocardium is more dependent on extracellular calcium than the normal cardiac muscle.
Med Sci Monit
; 16(8): BR278-84, 2010 Aug.
Article
em En
| MEDLINE
| ID: mdl-20671609
BACKGROUND: The aim of this study was to analyze stable hypertrophied myocardial function and its response to inotropic maneuvers in rats submitted to renovascular hypertension for a 10-week period (RHT group, n=10). MATERIAL/METHODS: Myocardial performance was studied in isolated left ventricle papillary muscles in isometric contraction under the following conditions: at postrest contraction of 30 seconds (PRC), at extracellular calcium (ECa2+) chloride concentration of 1.25 and 5.20 mM, and after beta-adrenergic stimulation with 10-6 M isoproterenol (ISOP). RESULTS: The results were compared with normotensive Wistar controls rats (C group, n=10). In basal condition, resting tension, and contraction time (TPT) were greater, while relaxation time (RT50) tended to be longer in RHT than C group. PRC and ISOP promoted a similar change in muscle function response intensity (delta) in both groups. ECa2+ shift did not change TPT in the C group and decreased TPT in the RHT animals; delta was different between these groups. RT50 increased in C and decreased in RHT, both without statistical significance; however, delta was different. CONCLUSIONS: These results suggest that hypertrophied myocardial dysfunction may be attributed to changes in intracellular calcium cycling.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cálcio
/
Espaço Extracelular
/
Miocárdio
Limite:
Animals
Idioma:
En
Revista:
Med Sci Monit
Assunto da revista:
MEDICINA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos