Renal blood flow (RBF) autoregulation was examined in untreated 10- and 40-wk-old spontaneously hypertensive rats (SHR) [mean arterial pressure (MAP) 125 +/- 4 and 167 +/- 7 mmHg] and in captopril-treated (7 days) 10- and 40-wk-old SHR (88 +/- 7 and 112 +/- 5 mmHg). Age-matched Wistar-Kyoto rats (WKY) were used as controls (MAP 91 +/- 3 and 104 +/- 2 mmHg). The study was carried out in rats with and without acute uninephrectomy. In 10-wk-old acutely uninephrectomized animals, the lower pressure limit of autoregulation was 78 +/- 4 mmHg in WKY, 102 +/- 5 mmHg in SHR (P less than 0.02), and 78 +/- 7 mmHg in captopril-treated SHR (P greater than 0.10). The renal vascular resistance (RVR) was significantly elevated at the lower pressure limit of RBF autoregulation in untreated SHR (P less than 0.02) but became normal after treatment (P greater than 0.10). Neither uninephrectomy nor variation of RBF between different batches seemed to influence the lower pressure limit of RBF autoregulation. In 40-wk-old acutely nephrectomized animals, the lower pressure limit of RBF autoregulation in WKY was 85 +/- 4 mmHg, 128 +/- 3 mmHg in SHR (P less than 0.001), and 101 +/- 5 mmHg in captopril-treated SHR (P less than 0.01). RVR at the lower pressure limit was increased in untreated SHR (P less than 0.01), but fell to normal values during captopril treatment. Neither the uninephrectomy nor variation of RBF between different batches of rats seemed to influence the lower pressure limit of RBF autoregulation.(ABSTRACT TRUNCATED AT 250 WORDS)
BackgroundPoor nutritional status of patients with renal disease has been associated with worsening of renal function and poor health outcomes. Simply measuring weight and height for calculation of the body mass index does however not capture the true picture of nutritional status in these patients. Therefore, we measured nutritional status by BMI, body composition, waist circumference, dietary intake and nutritional screening in three groups of renal patients.MethodsPatients with chronic kidney disease not on renal replacement therapy (CKD stages 3–5, n = 112), after renal transplantation (n = 72) and patients treated with hemodialysis (n = 24) were recruited in a tertiary hospital in Bergen, Norway in a cross-sectional observational study. Dietary intake was assessed by a single 24 h recall. All patients underwent nutritional screening, anthropometric measurements, body composition measurement andfunctional measurements (hand grip strength). The prevalence of overweight and obesity, central obesity, sarcopenia, sarcopenic obesity and nutritional risk was calculated.ResultsCentral obesity and sarcopenia were present in 49% and 35% of patients, respectively. 49% of patients with central obesity were normal weight or overweight according to their BMI. Factors associated with central obesity were a diagnosis of diabetes and increased fat mass, while factors associated with sarcopenia were age, female gender, number of medications. An increase in the BMI was associated with lower risk for sarcopenia.ConclusionCentral obesity and sarcopenia were present in renal patients at all disease stages. More attention to these unfavorable nutritional states is warranted in these patients.
Renal blood flow (RBF) autoregulation was examined in the clipped and nonclipped kidneys in two groups of two-kidney, one-clip (2K-1C) hypertensive rats 10 wk after clipping. The arterial pressure distal to the clip and the renin secretion rate (RSR) were also examined. The blood pressure (BP) was 149 +/- 4 and 162 +/- 6 mmHg in the two hypertensive groups vs. 114 +/- 3 mmHg in the controls (P less than 0.02). The RBF (in ml X min-1 X kidney-1) was 4.27 +/- 0.41 in the nonclipped and 2.18 +/- 0.23 in the clipped kidneys (P less than 0.001). The pressure distal to the clip was 104 +/- 7 mmHg. The renal vascular resistance (RVR) (in mmHg X ml-1 X min-1 X g-1) was 25.0 +/- 1.4 in the control kidneys vs. 58.4 +/- 4.5 in the nonclipped (P less than 0.001) and 39.9 +/- 6.6 in the clipped kidneys (P less than 0.01). The RBF autoregulation was well preserved in the nonclipped kidneys but reset to a higher lower pressure limit of autoregulation of 106 +/- 4 mmHg, which was significantly higher than in the normotensive controls (84 +/- 6 mmHg) (P less than 0.01). In the clipped kidneys there was complete loss of RBF autoregulation. RSR decreased with reduction of the perfusion pressure in the clipped kidneys. The increased RVR might have been due to a combination of structural and functional changes in both kidneys.
The effect of acute and chronic indomethacin treatment on renal blood flow (RBF) autoregulation was studied in 10- and 40-wk-old spontaneously hypertensive rats (SHR). RBF autoregulation was substantially reduced in 40-wk-old SHR both during acute and chronic indomethacin treatment, whereas no effect was seen in the young SHR. The pressure range of autoregulation was 169 +/- 9 to 130 +/- 5 mmHg in the untreated 40-wk-old SHR, and 154 +/- 14 to 146 +/- 6 mmHg in indomethacin-treated 40-wk-old SHR (P less than 0.001). Indomethacin treatment had no effect on control RBF, mean arterial pressure, or renal vascular resistance in the 40-wk-old SHR. After removal of the renal nerves, RBF autoregulation during indomethacin treatment was restored in 40-wk-old SHR. The pressure range of RBF autoregulation was 158 +/- 7 to 142 +/- 7 mmHg in sham-operated animals, significantly different from the denervated 40-wk-old SHR, where RBF was autoregulated from 150 +/- 5 to 118 +/- 6 mmHg (P less than 0.01) during indomethacin treatment. The afferent arteriolar diameter (DAA) was studied by the microsphere method in 10-wk-old SHR and in untreated and indomethacin-treated 40-wk-old SHR. DAA was significantly greater in 40-wk-old compared with 10-wk-old SHR (22.1 +/- 0.4 vs. 17.9 +/- 0.5 microns) (P less than 0.01), whereas indomethacin treatment in 40-wk-old SHR did not influence the DAA significantly (21.5 +/- 0.3 microns, P greater than 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)
The acute renal hemodynamic changes during induction of passive Heymann nephritis (PHN) may be of importance for the understanding of the pathogenesis of this model. We studied the renal blood flow (RBF) and glomerular filtration rate (GFR) during and after infusion of anti-FxlA into the left renal artery of rats for 10 min. 3 control groups were given 0.9% NaCl, 1 and 2 mg of normal rabbit IgG, respectively. The experimental groups were given 1 and 2 mg IgG fraction of anti-FxlA. Compared to controls, both RBF and GFR were substantially reduced during the first 20–30 min after infusion and remained unaltered for the rest of the observation period. After 20–30 min, RBF in the 1-mg group was 4.8 ± 0.77 ml/min/g kidney weight versus control, 6.4 ± 1.23 (NS), and in the 2-mg group, 3.5 ± 0.65 ml/min/g versus control, 6.4 ± 1.07 (p < 0.05). Similarly, in the 1-mg group, GFR was 0.40 ± 0.08 ml/min/g versus control, 0.76 ± 0.11 (p < 0.05), and in the 2-mg group, 0.14 ± 0.05 versus control, 0.77 ± 0.12 (p < 0.0001). The reductions were greater in the 2-mg than in the 1-mg infused experimental groups, but this difference did not reach statistical significance. Immunofluorescence showed typical granular fluorescence of rabbit IgG along the glomerular basement membrane, and electron microscopy showed subepithelial immune deposits. This indicates that in the initial phase of PHN, corresponding with the formation of immune complexes, a pronounced fall in RBF and GFR occurs.
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