Training/detraining-induced gender specific functional adaptations of isolated rat heart

Abstract

Background/Aim. Mechanisms responsible for the bene-ficial effects of aerobic exercise training on cardiovascular function are well known, but detraining effects on myo-cardial parameters have not been adequately elucidated. Therefore, the study aimed to determine the occurrence and speed of cardiac adaptation reversibility after the ces-sation of aerobic exercise and to reveal gender differences in achieved effects of training/detraining. Methods. Fe-male and male Wistar albino rats were divided into the fol-lowing groups: Control, trained, and two detrained groups. Hearts were perfused according to the Langendorff tech-nique and the following cardiodynamic parameters were determined: The maximum and minimum rate of pressure development in the left ventricle (dp/dt max and dp/dt min, respectively), systolic and diastolic left ventricular pressure (SLVP and DLVP, respectively), heart rate (HR), and coronary flow. Results. Training significantly reduced values of dp/dt max, dp/dt min, and SLVP in males and females, and coronary flow in males. Detraining caused a reversion of those changes, which was gender-specific. In females, levels of SLVP were higher after 4 weeks of de-training compred to training, and after 2 weeks of detrain-ing. Values of SLVP were lower in both detraining periods compared to training in males. Males had higher coronary flow after 2 weeks of detraining. Simultaneously, coronary flow was reduced in the 4th week of detraining in females. Conclusion. By using a model of the isolated rat heart, the present study confirmed the existence of training-induced changes in cardiac function. Cessation of training was followed by the loss of those adaptations, faster in males than females.