Abstract
Static exercise is well known to increase heart rate, arterial blood pressure, and ventilation. These increases appear to be less in women than in men, a difference that has been attributed to an effect of estrogen on neuronal function. In decerebrate male cats, we examined the effect of estrogen (17β-estradiol; 0.001, 0.01, 0.1, and 1.0 μg/kg iv) on the cardiovascular and ventilatory responses to central command and the exercise pressor reflex, the two neural mechanisms responsible for evoking the autonomic and ventilatory responses to exercise. We found that 17β-estradiol, in each of the three doses tested, attenuated the pressor, cardioaccelerator, and phrenic nerve responses to electrical stimulation of the mesencephalic locomotor region (i.e., central command). In contrast, none of the doses of 17β-estradiol had any effect on the pressor, cardioaccelerator, and ventilatory responses to static contraction or stretch of the triceps surae muscles. We conclude that, in decerebrate male cats, estrogen injected intravenously attenuates cardiovascular and ventilatory responses to central command but has no effect on responses to the exercise pressor reflex.
Original language | English (US) |
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Pages (from-to) | 1635-1641 |
Number of pages | 7 |
Journal | Journal of Applied Physiology |
Volume | 92 |
Issue number | 4 |
State | Published - 2002 |
Keywords
- Arterial blood pressure
- Exercise pressor reflex
- Heart rate
- Muscle afferents
- Tendon stretch
ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation