One-time acute heat treatment significantly attenuated the amplified mean arterial pressure response to static muscle contraction in rats with femoral artery occlusion (19 ± 8 mmHg vs 28 ± 2 mmHg, p < 0.05).
Does one-time acute heat treatment reduce the exaggerated exercise pressor reflex in a rat model of peripheral arterial insufficiency?
One-time acute heat treatment selectively attenuates the amplified pressor response to muscle contraction in a rat model of peripheral arterial insufficiency, likely by reducing metabolites stimulating muscle afferent nerves.
Absolute Event Rate: 19% vs 28%
p-value: p=<0.05
The purpose of this study was to determine the effects of one-time acute heat treatment (HT) on the exaggerated exercise pressor reflex in a model of peripheral arterial insufficiency induced by ligation of the femoral artery and to further examine the underlying mechanism of ATP-P2X3 signal activity during this process. The blood pressure (BP) response to static muscle contraction and muscle tendon stretch was recorded to determine the exercise pressor reflex. Also, αβ-methylene ATP (αβ-me ATP) was injected into the arterial blood supply of the hindlimb muscles to stimulate P2X3 receptors in the muscle afferent nerves. To process one-time acute HT, a heating pad was placed locally on the hindlimb and the muscle temperature (Tm) was increased by ~1.5 °C and maintained for 5 min. Compared with control rats, a greater mean arterial pressure (MAP) response to muscle contraction was observed in rats with femoral occlusion in a pre-heat control session (28±2 mmHg in occluded rats/n=12 vs. 18±2 mmHg in control rats/n=9; P0.05). Our data suggest that one-time acute HT selectively attenuates the amplified pressor response induced by activation of the metabolic and mechanical components of the reflex in rats after femoral artery occlusion. The suppressing effects of acute HT on the exaggerated exercise pressor reflex are likely mediated through a reduction in metabolites (e.g. ATP) stimulating the muscle afferent nerves in contracting muscle, but unlikely through direct alteration of P2X receptors per se.
Qin et al. (Thu,) conducted a other in Peripheral arterial insufficiency (femoral artery occlusion model) (n=44). One-time acute heat treatment vs. Pre-heat control session was evaluated on Mean arterial pressure (MAP) response to static muscle contraction (p=<0.05). One-time acute heat treatment significantly attenuated the amplified mean arterial pressure response to static muscle contraction in rats with femoral artery occlusion (19 ± 8 mmHg vs 28 ± 2 mmHg, p < 0.05).