Resonance in the kidney system of rats

Yu, Guimei; Wang, Yilong; Wang, W. K.

doi:10.1152/ajpheart.1994.267.4.h1544

Cited by 32 publications

(41 citation statements)

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“…Resonance for the counterpulsation pulses was not measured (18). In the rat abdominal aorta, weak resonant frequencies were recorded at the second and third harmonic, with the third harmonic significantly greater than the second harmonic of the fundamental (56). In another study using the rat thoracic aorta, a well-defined resonant peak measured by forced oscillation was recorded at 20 Hz, which is approximately the third harmonic of the rat HR in the present study (9).…”

Section: Discussioncontrasting

confidence: 41%

Low-amplitude pulses to the circulation through periodic acceleration induces endothelial-dependent vasodilatation

Uryash

Wu²,

Bassuk³

et al. 2009

Journal of Applied Physiology

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Uryash A, Wu H, Bassuk J, Kurlansky P, Sackner MA, Adams JA. Low-amplitude pulses to the circulation through periodic acceleration induces endothelial-dependent vasodilatation. J Appl Physiol 106: 1840 -1847, 2009. First published March 26, 2009 doi:10.1152/japplphysiol.91612.2008.-Low-amplitude pulses to the vasculature increase pulsatile shear stress to the endothelium. This activates endothelial nitric oxide (NO) synthase (eNOS) to promote NO release and endothelial-dependent vasodilatation. Descent of the dicrotic notch on the arterial pulse waveform and a-to-b ratio (a/b; where a is the height of the pulse amplitude and b is the height of the dicrotic notch above the end-diastolic level) reflects vasodilator (increased a/b) and vasoconstrictor effects (decreased a/b) due to NO level change. Periodic acceleration (pG z) (motion of the supine body head to foot on a platform) provides systemic additional pulsatile shear stress. The purpose of this study was to determine whether or not pG z applied to rats produced endothelial-dependent vasodilatation and increased NO production, and whether the latter was regulated by the Akt/phosphatidylinositol 3-kinase (PI3K) pathway. Male rats were anesthetized and instrumented, and pG z was applied. Sodium nitroprusside, N G -nitro-L-arginine methyl ester (L-NAME), and wortmannin (WM; to block Akt/PI3K pathway) were administered to compare changes in a/b and mean aortic pressure. Descent of the dicrotic notch occurred within 2 s of initiating pG z. Dose-dependent increase of a/b and decrease of mean aortic pressure took place with SNP. L-NAME produced a dose-dependent rise in mean aortic pressure and decrease of a/b, which was blunted with pG z. In the presence of WM, pGz did not decrease aortic pressure or increase a/b. WM also abolished the pG z blunting effect on blood pressure and a/b of L-NAME-treated animals. eNOS expression was increased in aortic tissue after pG z. This study indicates that addition of low-amplitude pulses to circulation through pG z produces endothelial-dependent vasodilatation due to increased NO in rats, which is mediated via activation of eNOS, in part, by the Akt/PI3K pathway. vascular resistance; N G -nitro-L-arginine methyl ester, wortmannin; nitric oxide ADDED LOW-AMPLITUDE PULSES to the vasculature were generated with periodic acceleration (pG z ). pG z is produced by a motorized platform that repetitively moves the horizontally oriented body sinusoidally in a head to foot direction. Inertia of fluid as the body accelerates and decelerates adds a small-amplitude pulse to the circulation that is superimposed on the natural pulse, increasing pulsatile shear stress to the endothelium (3, 6, 7). In large-animal models, increased pulsatile shear stress activates endothelial nitric oxide (NO) synthase (eNOS) to release NO into the circulation, which, in turn, induces endothelial-dependent pulmonary and systemic vasodilatation, as well as increasing organ blood flows (3,5,6). pG z applied to anesthetized swine increases serum nitrite, which is ...

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Section: Discussioncontrasting

confidence: 41%

Low-amplitude pulses to the circulation through periodic acceleration induces endothelial-dependent vasodilatation

Uryash

Wu²,

Bassuk³

et al. 2009

Journal of Applied Physiology

View full text Add to dashboard Cite

show abstract

“…In recent years, techniques developed for measuring, processing, and analyzing the physiological signals [3][4][5] are considered in computerized pulse signal research [6][7][8]. A series of pulse signal acquisition systems [9,10] have recently been developed and a number of methods have been proposed to analyze the digitized pulse signals [11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Wrist blood flow signal-based computerized pulse diagnosis using spatial and spectrum features

Zhang¹,

Zuo²,

Zhang³

et al. 2010

JBiSE

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Current computerized pulse diagnosis is mainly based on pressure and photoelectric signal. Considering the richness and complication of pulse diagnosis information, it is valuable to explore the feasibility of novel types of signal and to develop appropriate feature representation for diagnosis. In this paper, we present a study on computerized pulse diagnosis based on blood flow velocity signal. First, the blood flow velocity signal is collected using Doppler ultrasound device and preprocessed. Then, by locating the fiducial points, we extract the spatial features of blood flow velocity signal, and further present a Hilbert-Huang transform-based method for spectrum feature extraction. Finally, support vector machine is applied for computerized pulse diagnosis. Experiment results show that the proposed method is effective and promising in distinguishing healthy people from patients with cholecystitis or nephritis.

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“…To eliminate the effects of time -variant F, amplitude of each harmonic was normalized by its mean level (DC component) and named harmonic proportion. Because the amplitude decreased rapidly with the harmonic numbers, we focused only on the first six harmonics [8][9][10]. The fitting procedure was similar with our previous work [3].…”

Section: Discussionmentioning

confidence: 99%

“…The signal was connected to a simultaneous sample -and-hold panel AX753 and then to a 16-bit AD converter AX5621. These cards converted signals to digital data with sampling frequency 1500 Hz, and sent them to a personal computer for further analysis [8][9][10].…”

Section: Methodsmentioning

confidence: 99%

“…In the conjecture of the resonance theory, the arterial system is treated as a pressure-wave-transmitting system, the pulse pressure arriving at the terminal will drive the blood flux into the microcirculation [3][4][5][6][7][8][9][10]. Therefore the radial dilatation of the vessel wall was emphasized, and the pressure wave is transmitted in the form of "moving windkessel" [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Applying the resonance equation to the blood pressure waveform variation in aorta bending and renal ligation of rats

Hsiu

Jan

Wang³

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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-In the resonance theory, the radial dilatation is emphasized, and the blood pressure wave is transmitted in the form of "moving windkessel". Based on this conjecture, we developed a semi-empirical procedure to describe the pressure distribution in a complex simulated model composed of a main tube and attached organs. Now we try to apply this fitting method to hemodynamics in vivo, and we tested our equations by two sets of experiments on the rats: ligating a renal artery and bending the aorta transversely. Abdominal aortic blood pressure of rat was measured through tubes inserted from the caudate artery and compared with curve-fitting deduced from semi-empirical resonance equations. The good fitting result illustrates that in spite of various complex structures of the arterial system, we can still provide good description for the blood pressure distribution by dividing the arterial system into sub-units and describing with few elastic parameters. It reinforces the conjecture of the resonance theory.

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Resonance in the kidney system of rats

Cited by 32 publications

References 0 publications

Low-amplitude pulses to the circulation through periodic acceleration induces endothelial-dependent vasodilatation

Low-amplitude pulses to the circulation through periodic acceleration induces endothelial-dependent vasodilatation

Wrist blood flow signal-based computerized pulse diagnosis using spatial and spectrum features

Applying the resonance equation to the blood pressure waveform variation in aorta bending and renal ligation of rats

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