Cano-Martínez A, Vargas-González A, Guarner-Lans V
Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Juan Badiano # 1, Colonia Sección XVI, Tlalpan, México D.F. 14080, Mexico.
Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Juan Badiano # 1, Colonia Sección XVI, Tlalpan, México D.F. 14080, Mexico.
Comp Biochem Physiol A Mol Integr Physiol. 2007 Jul;147(3):743-749. doi: 10.1016/j.cbpa.2006.10.030. Epub 2006 Oct 27.
The spontaneous heart rate (HR) and ventricular (V) and atrium (A) tensions (T) were evaluated through isolated organ assays at different temperatures in hearts from Ambystoma dumerilii control and treated with isoproterenol (ISO) [(150 mg/kg i.p. each 24 h, for 3 days)] on days 1, 5, 30 and 90 after ISO. In control hearts, the HR increased and the T decreased when temperature was augmented. One day after ISO the HR (43-24%) and T (50-25%) decreased with respect to control, between 8 and 24 degrees C. Five, 30 and 90 days after ISO, HR showed a gradual recovery with similar effect when the temperature was changed; but the AT increased and VT decreased at temperatures between 8 and 12 degrees C and were only recovered at temperatures above 12 degrees C. Our results indicate that the HR recovers after ISO in A. dumerilii independently of temperature. The recovery of AT and VT is similar to HR at temperatures higher than 12 degrees C and the increases in VT could be compensating the decrease in VT caused by ISO, at temperatures lower than 12 degrees C. The changes in heart contractile activity of A. dumerilii after insult show the thermic plasticity that is observed in ectothermic vertebrates.
通过在不同温度下对钝口螈（Ambystoma dumerilii）对照心脏以及用异丙肾上腺素（ISO）[（每24小时腹腔注射150毫克/千克，共3天）]处理后的心脏进行离体器官测定，评估自发心率（HR）以及心室（V）和心房（A）张力（T）。在ISO处理后的第1天、第5天、第30天和第90天进行测定。在对照心脏中，当温度升高时，心率增加而张力降低。在ISO处理后一天，在8至24摄氏度之间，相对于对照，心率（降低43 - 24%）和张力（降低50 - 25%）下降。在ISO处理后的第5天、第30天和第90天，当温度改变时，心率显示出逐渐恢复且效果相似；但在8至12摄氏度之间，心房张力增加而心室张力降低，且仅在高于12摄氏度的温度下恢复。我们的结果表明，钝口螈在ISO处理后心率的恢复与温度无关。在高于12摄氏度的温度下，心房张力和心室张力的恢复与心率相似，并且在低于12摄氏度的温度下，心室张力的增加可能是在补偿由ISO引起的心室张力降低。钝口螈在受到损伤后心脏收缩活动的变化显示出变温脊椎动物中观察到的热可塑性。
