Introduction:
Literature findings suggest that fluctuations of female sex hormones may change the maximum oxygen consumption (VO2 max).
Objective:
To compare the VO2 max among male rats (M, n = 8), female rats on ovulatory (OV, n=8) or non-ovulatory (NOV, n=8) phases of the estrous cycle and ovariectomized (OS, n=8).
Methods:
The evaluation of oxygen consumption was performed on a treadmill coupled with metabolic box.
Results:
At rest VO2 was similar among groups. The M group had a higher VO2 max compared to the NOV group, however showed similar values when compared to OV group. The VO2 max was lower in the ovariectomized group (OS: 62±3 ml.kg-1.min-1) compared to other groups (M: 92±2; NOV: 77 ± 4; OV: 87 ± 3 ml.kg-1.min-1).
Conclusions:
These findings suggest that hormonal variation resulting from different phases of the estrous cycle and ovarian hormone deprivation can induce changes in maximal oxygen uptake in rats.
oxygen consumption; rats; sex differences; menopause