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In decerebrate rats, we reported previously that the exercise pressor reflex arising from a limb whose femoral artery was occluded for 72 h before the experiment was significantly higher than the exercise pressor reflex arising from a contralateral freely perfused limb. These findings prompted us to examine whether reactive oxygen species contributed to the(More)
Cyclooxygenase metabolites stimulate or sensitize group III and IV muscle afferents, which comprise the sensory arm of the exercise pressor reflex. The thromboxane (TP) receptor binds several of these metabolites, whose concentrations in the muscle interstitium are increased by exercise under freely perfused conditions and even more so under ischemic(More)
Exercise in hypertensive individuals elicits exaggerated increases in mean arterial pressure (MAP) and heart rate (HR) that potentially enhance the risk for adverse cardiac events or stroke. Evidence suggests that exercise pressor reflex function (EPR; a reflex originating in skeletal muscle) is exaggerated in this disease and contributes significantly to(More)
In hypertension, exercise elicits excessive elevations in mean arterial pressure (MAP) and heart rate (HR) increasing the risk for adverse cardiac events and stroke during physical activity. The exercise pressor reflex (a neural drive originating in skeletal muscle), central command (a neural drive originating in cortical brain centres) and the tonically(More)
The skeletal muscle exercise pressor reflex (EPR) induces increases in heart rate (HR) and mean arterial pressure (MAP) during physical activity. This reflex is activated during contraction by stimulation of afferent fibres responsive to mechanical distortion and/or the metabolic by-products of skeletal muscle work. The molecular mechanisms responsible for(More)
We investigated the contribution of tetrodotoxin (TTX)-resistant sodium channels to the augmented exercise pressor reflex observed in decerebrated rats with femoral artery ligation. The pressor responses to static contraction, to tendon stretch, and to electrical stimulation of the tibial nerve were compared before and after blocking TTX-sensitive sodium(More)
NEW FINDINGS What is the central question of this study? Does increasing NO production within the nucleus tractus solitarii (NTS) affect mechanoreflex function in normotensive and hypertensive rats?What is the main finding and its importance? Dialysis of 1 μm l-arginine, an NO precursor, within the NTS significantly attenuated the pressor response to muscle(More)
Evidence suggests that the muscle mechanoreflex, a circulatory reflex that raises blood pressure and heart rate (HR) upon activation of mechanically sensitive afferent fibres in skeletal muscle, is overactive in hypertension. However, the mechanisms underlying this abnormal reflex function have yet to be identified. Sensory input from the mechanoreflex is(More)
The cardiovascular response to exercise is abnormally large in hypertension. Over the past decade, it has become clear that the exercise pressor reflex (a peripheral feed-back mechanism originating in skeletal muscle) contributes significantly to the generation of this hyper-responsiveness. Further, it has been determined that overactivity of the(More)
In rats with ligated femoral arteries, the exercise pressor reflex is exaggerated, an effect that is attenuated by stimulation of peripheral μ-opioid receptors on group IV metabosensitive afferents. In contrast, δ-opioid receptors are expressed mostly on group III mechanosensitive afferents, a finding that prompted us to determine whether stimulation of(More)