Abstract 269: Cardiac Aging in Rats: Do Female and Male Hearts Age Differently?
Background: In recent years, the use of middle-aged and old animals of both sexes has become preferential in experimental studies involving the models of cardiovascular diseases to better reflect a human population. However, the evidence showing the extent of sex-related differences in cardiac aging of laboratory animals remains obscure. Accordingly, we designed our study to determine whether the male and female rats differ during aging with regard to left ventricular (LV) geometry and systolic function.
Methods: We performed transthoracic echocardiographic examinations in 12-month-old (12mo) and 24 month-old (24mo) male and female Sprague-Dawley rats (Charles River, Wilmington, MA) under 1.5% isoflurane anesthesia using a linear (Matrix) array transducer probe GE M12L (5.5-14.0 MHz) and a GE Vivid 7 Dimension ultrasound system. Two-dimensional short-axis views and M-mode tracings of the LV at the papillary muscle level were recorded and used to estimate various LV parameters.
Results: We found that 24mo-Female rats had a significant increase in LV chamber dimensions associated with a reduction in its systolic performance as compared to 12mo-Female rats (Table 1). In contrast, LV parameters remained similar between 12mo- and 24mo-Male rats. Table 1. Echocardiographic parameters of LV chamber geometry and systolic performance Values are means ± SE. Arrow indicates a significant difference between age groups (P ≤ 0.05).
Conclusion: Our data demonstrate that during cardiac aging female rats have a different pattern of LV changes compared to males that must be considered in the design of future experimental studies.
- © 2012 by American Heart Association, Inc.