In spontaneously hypertensive rats, there was a significant negative association between low-frequency mean arterial pressure and operational distensibility (r = -0.48, p < 0.01).
Does autonomic nervous system inhibition alter the relationship between low-frequency blood pressure variability and arterial distensibility in spontaneously hypertensive rats?
In spontaneously hypertensive rats, there is a strong association between increased low-frequency mean arterial pressure and reduced arterial distensibility, modulated by the autonomic nervous system.
Effect estimate: r = -0.48
p-value: p=< 0.01
The aim of this study was to determine in spontaneously hypertensive rats (SHRs) whether a significant association may be observed between the low-frequency component of blood pressure variability (BPV) and arterial distensibility and to evaluate the role of the autonomic nervous system in this relationship. Doxazosin (1 mg/kg/d s.c.), flesinoxan (1 mg/kg/d s.c.), and urapidil (30 mg/kg/d s.c.) were infused over 24 h in SHRs. Blood pressure was recorded in conscious rats and BPV was characterized by spectral analysis. The distensibility-pressure curves for the carotid artery were determined by an ultrasonic echo-tracking device in anesthetized rats. Untreated SHRs had higher mean arterial pressure (MAP) and low-frequency MAP but a lower distensibility than normotensive Wistar-Kyoto rats. In SHRs inhibition of the autonomic nervous system by peripheral blockade of alpha1-adrenoceptors (doxazosin, 1 mg/kg, or urapidil, 30 mg/kg) or centrally mediated reduction of sympathetic tone (flesinoxan, 1 mg/kg) reduced MAP and low-frequency MAP in the conscious state and increased carotid operational distensibility in the anesthetized state. In these SHRs, we observed a negative association between low-frequency MAP and operational distensibility ( r = -0.48, p < 0.01). From multiple regression analysis, MAP and low-frequency MAP, but not drug treatment, influenced arterial distensibility. Our study in SHRs provides evidence for a strong association between increased low-frequency MAP and reduced arterial distensibility, with a common modulation provided by the autonomic nervous system via the alpha 1 -adrenergic receptor component and central nervous system.
Dabiré et al. (Tue,) conducted a other in Hypertension (Spontaneously hypertensive rats). Doxazosin, flesinoxan, and urapidil vs. Untreated SHRs and normotensive Wistar-Kyoto rats was evaluated on Association between low-frequency mean arterial pressure and operational distensibility (r = -0.48, p=< 0.01). In spontaneously hypertensive rats, there was a significant negative association between low-frequency mean arterial pressure and operational distensibility (r = -0.48, p < 0.01).