Pancreatic Microcirculation Profiles in the Progression of Hypertension in Spontaneously Hypertensive Rats

Figures

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  Figure 1.. Pancreatic microcirculation profiles in the progression of hypertension. (a) Pancreatic microvascular vasomotion of WKYs and SHRs. The velocity was extracted in the rectangular insert. The microcirculatory blood perfusion between dashed lines (5 seconds) is illustrated in the square insert. (b) Pancreatic microcirculatory blood distribution pattern of WKYs and SHRs. The red dot represents WKY. The blue dot represents SHR. The green dashed line represents the boundary of the microcirculatory blood distribution pattern between WKYs and SHRs. (c) Quantification analysis of pancreatic microhemodynamic data including average blood perfusion (PU/minutes), relative velocity (PU), amplitude (ΔPU), and frequency (cycles/minutes) of WKYs and SHRs at 5, 8, 13, and 18 weeks. All data are presented as the mean ± SEM. *P < 0.05 compared with WKYs, #P < 0.01 compared with WKYs. The red line and dots, microcirculatory data of WKYs. The blue line and dots represent SHRs. Abbreviations: PU, perfusion unit; SHR, spontaneously hypertensive rat; WKY, Wistar Kyoto rat.

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  Figure 2.. 3-D characteristic amplitude spectral scalograms of pancreatic microcirculation profiles. 3-D time–frequency spectral scalograms derived from pancreatic microcirculation profiles data corresponding to microcirculatory blood perfusion signals in SHRs and WKYs at 5, 8, 13, and 18 weeks were illustrated utilizing wavelet coefficients. Microhemodynamic variants,including time (seconds), frequency (Hz), and spectral amplitude (AU), were located in the coordinates. The gradient colored scalogram ranging from dark blue (low energy) to light orange (high energy) represents an energy continuous wavelet coefficient and spectral amplitudes. Arrows indicate the frequencies characterized by endothelial oscillators. Abbreviations: SHRs, spontaneously hypertensive rats; WKYs, Wistar Kyoto rats.

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  Figure 3.. Quantification analyses of characteristic oscillatory amplitudes of pancreatic microcirculation profiles. The combination of laser Doppler flowmetry with wavelet transform signal processing analysis was performed to reveal microcirculatory oscillations related to physiological phenomena. The entire frequency derived from laser Doppler signals was divided into a set of frequency bands, each of which contains a single peak: 0.01–0.015, 0.015–0.04, 0.04–0.15, 0.15–0.4, 0.4–2, and 2–5 Hz, attributed to NO-independent endothelial and NO-dependent endothelial, neurogenic, myogenic, respiratory, and cardiac oscillators, respectively. (a) Comparisons of the mean amplitudes of characteristic oscillators in pancreatic microcirculation profiles of WKYs and SHRs at 5, 8, 13, and 18 weeks. (b) Radar plots represent varying distributions and differences across amplitudes of characteristic frequency bands corresponding to physiological oscillators. The red line represents amplitudes of WKYs, and the blue line represents amplitudes of SHRs. Abbreviations: SHRs, spontaneously hypertensive rats; WKYs, Wistar Kyoto rats.

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  Figure 4.. Pancreatic microvascular endothelial cell dysfunction in the progression of hypertension. (a) Correlation between endothelial oscillator and microcirculatory blood perfusion. (b) Correlations between endothelial oscillator and blood pressure. (c) The mean amplitude (AU) of NO-dependent and NO-independent endothelial oscillators in WKYs and SHRs. The ratios of NO-dependent and NO-independent endothelial oscillators are shown in the upper pie chart. Red dots, mean amplitude of NO-dependent endothelial oscillator. Blue triangles indicate the amplitude of the NO-independent endothelial oscillator. (d) The levels of plasma nitrite/nitrate, ET-1, MDA, SOD, and IL-6 in WKYs and SHRs. *P < 0.05 compared with WKYs, #P < 0.01 compared with WKYs. Abbreviations: DBP, diastolic blood pressure; ET-1, endothelin-1; IL-6, interleukin-6; MDA, malondialdehyde; PU, perfusion unit; SBP, systolic blood pressure; SHRs, spontaneously hypertensive rats; SOD, superoxide dismutase; WKYs, Wistar Kyoto rats.