Data/hora: 01/06/2024 07:46:08

Provedor de dados: | 56
País: | Brazil
Título: | Effects of short-term administration of estradiol on reperfusion arrhythmias in rats of different ages
Autores: | Savergnini,S.Q.; Reis,A.M.; Santos,R.A.S.; Santos,P.E.B.; Ferreira,A.J.; Almeida,A.P.
Data: | 2012-12-01
Ano: | 2012
Palavras-chave: | Cardioprotection; Estrogen; Ischemia/reperfusion; Langendorff technique; QT interval.
Resumo: | Little is known about age-related differences in short-term effects of estradiol on ischemia-reperfusion (I/R) insults. The present study was designed to evaluate the effects of short-term treatment with estradiol on reperfusion arrhythmias in isolated hearts of 6-7-week-old and 12-14-month-old female rats. Wistar rats were sham-operated, ovariectomized and treated with vehicle or ovariectomized and treated with 17β-estradiol (E2; 5 µg·100 g-1·day-1) for 4 days. Hearts were perfused by the Langendorff technique. Reperfusion arrhythmias, i.e., ventricular tachycardia and/or ventricular fibrillation, were induced by 15 min of left coronary artery ligation and 30 min of reperfusion. The duration and incidence of I/R arrhythmias were significantly higher in young rats compared to middle-aged rats (arrhythmia severity index: 9.4 ± 1.0 vs 3.0 ± 0.3 arbitrary units, respectively, P &lt; 0.05). In addition, middle-aged rats showed lower heart rate, systolic tension and coronary flow. Four-day E2 treatment caused an increase in uterine weight. Although E2 administration had no significant effect on the duration of I/R arrhythmias in middle-aged rats, it induced a marked reduction in the rhythm disturbances of young rats accompanied by a decrease in heart rate of isolated hearts. Also, this reduction was associated with an increase in QT interval. No significant changes were observed in the QT interval of middle-aged E2-treated rats. These data demonstrate that short-term estradiol treatment protects against I/R arrhythmias in hearts of young female rats. The anti-arrhythmogenic effect of estradiol might be related to a lengthening of the QT interval.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200020
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2012007500169
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.45 n.12 2012
Fonte: | info:eu-repo/semantics/openAccess