Specific frequency properties of renal and superior mesenteric arterial beds in rats

Abstract

In order to investigate the effects of arterial beds on pressure waveforms in arteries, the pressure waves observed in the rat tail artery were resolved into their Fourier moduli before and during ligation of the left renal artery and the superior mesenteric artery. Consistently different patterns of waveform changes in the tail artery were seen on occlusion of these vessels. Ligation of the renal artery reduced, and of the superior mesenteric artery increased, the pressure harmonics over most of the spectra. These results imply that to study the changes in the pressure contours as the observation point is moved downstream, one may have to account separately for the contributions of individual arterial beds. This is relevant in considering the degree to which it is appropriate for data to be amalgamated in models of the systemic arterial bed.

Assessment of Parasympathetic Control of Blood Vessel by Pulsation Spectrum and Comparison With Spectral Method of Rr Intervals

“…[33][34][35][36] The pulsatile nature of the arterial pressure and flow combined with the elastic properties of vessel, the viscosity and inertial nature of blood, and the variable compliance and geometry of vascular system introduce phase relationships between the arterial pressure and flow.…”

“…In most models, the blood vessels are treated as a string of identical units chained together, so that pressure and flow waves pass through each one of them in sequence. The mathematical expression of such an arrangement is called a transmission-line model [33][34]. Taylor designed an electrical network for a mathematical transmission-line model to simulate the effects of viscoelasticity in the walls of blood vessels.…”

“…[33][34][35][36][37] The Fourier components of the pulse are related to the resonant condition of blood pressure distribution and tissue. The physical conditions of the internal organs or tissues will influence their resonant status and the distributions of blood pressure.…”

“…The physical conditions of the internal organs or tissues will influence their resonant status and the distributions of blood pressure. By analyzing pulse spectrum variation with organ clamping, [33][34][35] acupuncture [38,39] and herb feeding experiments, [40] the resonance frequencies of different organs can be found. Internal organs are correlated with different harmonics of pressure pulse e.g.…”

“…liver is related to the I st harmonic; kidney, the 2nd; spleen, the 3rd; lung, the 4th; stomach, the 5th; and so on. [33][34][35][38][39][40] In this study, we use the pulse spectrum method to observe the change of the blood energy distribution, while parasympathetic vasodilator nerve is blocked, and compare with the conventional method--spectral analysis of HRV.…”