The aim of this study was to conduct in vivo experiments using laser speckle contrast imaging (LSCI) technology to investigate the effects of high salt diet on renal vascular reactivity in mice. LSCI is a technology for monitoring blood flow based on the laser speckle principle. It has been widely used to detect microcirculatory functions in tissues such as the skin and brain. The kidneys are located behind the peritoneum, and their position is easily affected by the movement of abdominal organs. Measuring renal microcirculation in a living individual is difficult. The present study used a self-made kidney cup to isolate the kidney and fix its position relatively, and then applied LSCI technology to explore the effect of high salt diet (8% Na⁺) on renal vascular reactivity in male and female mice in vivo. The results showed that a short-term high salt diet (1 week) did not affect the systolic blood pressure of the tail artery, while significantly increased glomerular filtration rate (GFR) and renal blood flow (RBF). Compared with the normal salt diet group, the high salt diet group showed a significant decrease in the ratio of post-occlusive reactive hyperemia (PORH) in male mice, while there was no significant change in the PORH ratio in female mice. These results suggest that, although a short-term high salt diet does not cause changes in blood pressure, it has already affected renal vascular reactivity and has gender differences in its effects. Furthermore, the present study provides a basis for renal microcirculation assessment using LSCI in vivo.
Animals ; Mice ; Male ; Female ; Kidney/blood supply* ; Renal Circulation/physiology* ; Laser Speckle Contrast Imaging ; Sodium Chloride, Dietary/adverse effects* ; Microcirculation/physiology* ; Mice, Inbred C57BL

In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure.
Aged ; Carotid Arteries/diagnostic imaging ; Cerebrovascular Circulation/*physiology ; Dizziness/etiology ; Female ; Hemodynamics/*physiology ; Humans ; Kidney Failure, Chronic/*physiopathology ; Male ; Middle Aged ; Renal Dialysis ; Risk Factors ; Ultrasonography, Doppler, Duplex

In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure.
Aged ; Carotid Arteries/diagnostic imaging ; Cerebrovascular Circulation/*physiology ; Dizziness/etiology ; Female ; Hemodynamics/*physiology ; Humans ; Kidney Failure, Chronic/*physiopathology ; Male ; Middle Aged ; Renal Dialysis ; Risk Factors ; Ultrasonography, Doppler, Duplex

OBJECTIVETo analyze the renal relative blood flow value (rBFV) and image quality in normal adults using single-shot fast spin echo, flow sensitive invention recovery (SSFSE-FAIR) magnetic resonance (MR) sequence and echo planar imaging, and flow sensitive invention recovery (EPI-FAIR) MR sequence, and assess its value for clinical application in routine renal examination.

METHODSForty volunteers (25 male and 15 female adults, aged 30 to 62 years) with normal renal function were included in this prospective study. All the subjects underwent 3.0 Tesla MR scanning using 3 MR scan modes, namely breath-holding EPI-FAIR, breath-holding SSFSE-FAIR and free breathing SSFSE-FAIR.

RESULTSSSFSE-FAIR without breath-holding was capable of differentiating the renal cortex and medulla with the corresponding rBFVs of 111.48∓9.23 and 94.98∓3.38, respectively. Breath-holding SSFSE-FAIR and EPI-FAIR failed to distinguish the borders of the renal cortex and medulla. The EPI-FAIR rBFV of mixed cortex and medulla value was 178.50∓17.17 (95%CI: 167.59, 189.41).

CONCLUSIONBreath-holding SSFSE-FAIR and EPI-FAIR can not distinguish the renal cortex and medulla due to a poor spatial resolution but can be used for rough evaluation of renal blood perfusion. Free breathing SSFSE-FAIR with an improved spatial resolution allows evaluation of the status of renal perfusion of the cortex and medulla.

Adult ; Echo-Planar Imaging ; methods ; Female ; Humans ; Kidney ; blood supply ; physiology ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Prospective Studies ; Renal Circulation

Contrast-enhanced ultrasound is one of method for evaluating renal perfusion. The purpose of this project was to assess perfusion patterns and dynamics in normal micropig kidney using ultrasonographic contrast media. Eight young healthy micropigs were included in this study. Micropigs were anesthetized with propofol and received an intravenous bolus of microbubble contrast media through an ear vein. Time/mean pixel value (MPV) curves were generated for selected regions in the right renal cortex and medulla. The parenchyma was enhanced in two phases. The cortex was first enhanced followed by a more gradual enhancement of the medulla. A significant difference in perfusion was detected between the cortex and medulla. Following the bolus injection, the average upslope was 0.68 +/- 0.27 MPV/sec, downslope was -0.27 +/- 0.13 MPV/sec, baseline was 73.9 +/- 16.5 MPV, peak was 84.6 +/- 17.2 MPV, and time-to-peak (from injection) was 17.5 +/- 6.6 sec for the cortex. For the medulla, the average upslope was 0.50 +/- 0.24 MPV/sec, downslope was -0.12 +/- 0.06 MPV/sec, baseline was 52.7 +/- 7.0 MPV, peak was 65.2 +/- 9.3 MPV, and time-to-peak (from injection) was 27.5 +/- 5.0 sec. These data can be used as normal reference values for studying young micropigs.
Animals ; Contrast Media/*diagnostic use ; Image Processing, Computer-Assisted ; Injections, Intravenous/veterinary ; Kidney/*blood supply/ultrasonography ; Kidney Function Tests/veterinary ; Linear Models ; Microbubbles/diagnostic use/veterinary ; Reference Values ; Renal Circulation ; Sulfur Hexafluoride/diagnostic use ; Swine ; Swine, Miniature/*physiology ; Ultrasonography/*methods/veterinary

OBJECTIVETo investigate the relationship between the severity of Chinese medicine (CM) blood stasis syndrome (BSS) with clinical features and renal lesion indexes of the primary glomerular disease.

METHODSAn epidemiological survey was conducted to collect the data of 227 patients diagnosed as chronic primary glomerular diseases, and their severity of BSS were scored three days before renal biopsies were performed. The following clinical indexes were analyzed: age, course of glomerular diseases, 24-h urine protein ration (Upro), hypertension and blood pressure (BP) progress, serum creatinine levels (Scr), estimation of glomerular filtration rate based on the predigesting equation of MDRD (eGFR), blood urea nitrogen (BUN), uric acid (UA), triglyceride (TG), cholesterol (CHO), haematoglobin (HGB), albumin (ALB), and the correlation among renal pathological types, pathology lesion indexes, and BSS scores.

RESULTS(1) Among the 227 patients, 207 (91.19%) were diagnosed as BSS, in which 95 cases were considered as moderate and the rest 112 cases as severe. (2) There was a negative correlation between age, gender, grades of the hypertension, and the BSS score. Multiple stepwise regression analysis showed that Upro, CHO, TG, and eGFR were positively related to the BSS score (P<0.05). (3) The BSS score has a positive correlation with indexes of chronic renal pathology, especially the tubular atrophy and interstitial fibrosis. The severity of proliferation and glomerular sclerosis was accompanied with higher BSS scores with a significant difference (P<0.05).

CONCLUSIONSBSS is one of the most common CM syndromes among patients with the primary glomerular diseases; the BSS score has a positive correlation with Upro, CHO, TG, eGFR, as well as the index of chronic renal pathology. Based on these observations, the BSS may be used as an indicator of the development of renal diseases. Being positively diagnosed as BSS could indicate the beginning of the chronic phase of the primary glomerular diseases.

Adolescent ; Adult ; Aged ; Blood Circulation ; physiology ; Female ; Glomerulonephritis ; pathology ; physiopathology ; Humans ; Hypertension, Renal ; pathology ; physiopathology ; Integrative Medicine ; Kidney ; pathology ; Male ; Medicine, Chinese Traditional ; Middle Aged ; Qi ; Renal Insufficiency, Chronic ; pathology ; physiopathology ; Severity of Illness Index ; Young Adult

Intravascular administration of magnesium (Mg) causes vasodilation and increases renal blood flow. The aim of this study was to investigate the renal effect of Mg following unclamping of the supraceliac aorta. Mongrels were divided into two groups, control (group C, n=7) and Mg group (group Mg, n=7). In group Mg, 30 mg/kg MgSO4 was injected as a bolus immediately prior to unclamping the supraceliac aorta and thereafter as an infusion (10 mg/kg/hr). The group C received an equivalent volume of saline solution. Systemic hemodynamics, renal artery blood flow, renal cortical blood flow (RCBF), renal vascular resistance, and renal function were compared. Following the aortic unclamping, cardiac output and RCBF were less attenuated, and the systemic and renal vascular resistance was elevated to a lesser degree in the group Mg compared to the group C. There was no significant difference in the plasma renin activity, serum creatinine and Cystatin-C between the two groups. The present study shows that Mg infusion improves systemic hemodynamics and RCBF after aortic unclamping. However, we did not observe any improvement in renal function when Mg was administered after supraceliac aortic unclamping.
Animals ; Aorta, Abdominal/physiology/*surgery ; Blood Pressure/drug effects ; Calcium/blood ; Cardiac Output/drug effects ; Comparative Study ; Creatinine/blood ; Cystatins/blood ; Dogs ; Female ; Heart Rate/drug effects ; Magnesium/blood ; Magnesium Sulfate/*pharmacology ; Male ; Renal Circulation/*drug effects ; Renin/blood ; Research Support, Non-U.S. Gov't

OBJECTIVE: To assess the usefulness of pulsatile flow detection (PFD), a newly developed function of color Doppler US, in measuring resistive index (RI) in renal Doppler US and to compare it with conventional color Doppler (CCD). MATERIALS AND METHODS: Fifty-six kidneys in 31 patients were randomly selected and divided into two groups. In group A, RI was measured first with the aid of CCD, and then with PFD. In group B, data were obtained in the reverse order. The time required for each RI measurement was recorded in seconds. The quality of the Doppler spectral waveform was subjectively graded as 0, 1, or 2 and examination time and waveform quality were compared between PFD and CCD. RESULTS: The time required to measure RI with PFD (PFD time) was less than with CCD (CCD time) (mean 42.7 secs vs. mean 70.3 secs; p = 0.031). There was no significant difference in PFD time between group A and B, but CCD time was shorter in group B (70.3 secs vs. 24.6 secs; p = 0.0004). Spectral waveform quality was not significantly different between PFD and CCD. CONCLUSION: The time required to measure RI in kidneys can be shortened with the aid of the PFD function in color Doppler US without affecting the quality of the examination.
Blood Flow Velocity/physiology ; Case-Control Studies ; Female ; Human ; Kidney/*ultrasonography ; Male ; Pulsatile Flow/physiology ; Renal Circulation/physiology ; Support, Non-U.S. Gov't ; *Ultrasonography, Doppler, Color

Although heparin is better known as an anticoagulant, it also has several anti-inflammatory effects. Heparin is known to inhibit neutrophil adhesion, chemotaxis and oxygen free radical production. In addition, heparin is also known to act as an oxygen radical scavenger. Our hypothesis was that heparin would attenuate renal ischemia reperfusion injury. In this study, we investigated whether heparin had a protective effect on renal ischemia reperfusion injury. Sheep (n = 12) were prepared for the chronic study with venous, arterial and urinary catheters inserted. In addition, pneumatic occluders and ultrasonic flow probes were placed on renal arteries. After a 5-day recovery period, the sheep were randomized to either a heparin treatment group (400 IU/kg i.v. bolus 10 minutes before renal artery occlusion, followed by a continuous effusion 25,000 IU in 250 ml of 0.9% NaCl at 10 ml/hr, n = 6) or a control group (n = 6), which received an equivalent volume of 0.9% NaCl. All the sheep then underwent 90 minutes of bilateral renal ischemia followed by 24 hours of reperfusion. Blood urea nitrogen (BUN), serum creatinine (Scr), and creatinine clearance (CrCl) were determined at various intervals during both the ischemic and reperfusion periods. Kidney tissue samples were obtained at autopsy for histologic examination. As a result, there were significant differences in the degree of inflammation (1.50 +/- 1.24 Vs 0.50 +/- 0.79, P < 0.05) between the control and heparin treatment groups, but not in the degree of injury (2.83 +/- 0.44 Vs 2.33 +/- 0.28). In this study, heparin significantly attenuated polymorphonuclear leukocytes (PMNs) infiltration within the interstitium, but it did not affect the degree of renal damage as measured by urinary chemistries or renal tubular damage as assessed by histopathologic evaluation.
Animal ; Anticoagulants/pharmacology* ; Cell Movement/drug effects ; Female ; Heparin/pharmacology* ; Ischemia/pathology* ; Kidney/pathology ; Kidney/drug effects* ; Neutrophils/physiology ; Neutrophils/drug effects* ; Renal Circulation* ; Reperfusion Injury/pathology* ; Sheep

This experiment involved 12 rabbits of both sexes, weighing 2.1 kg. After anesthesia, the kidneys were exposed, isolated and cannulated in the renal artery, ureter and sometimes in the vein as well. The kidney were perfused through the renal artery with Krebs-Henseleit solution, which were then filtered to be free of particles, gased with 95% O2-5% CO2, and kept at 37 degrees C. We measured RBCs concentrations by means of Coulter Counter in the venous outflow collected, and plotted them against the volume perfused. Using 2 different flow rates, 9 ml/min (group I) and 19 ml/min (group II), we found that the RBCs decreased in a multiexponential decay fashion and a biophysical model for each flow rate was constructed. These models indicated that there were more cell stores (2.20 x 10(10)) in the fast compartment of group II than in group I (1.72 x 10(10)). This difference is not statistically significant, but certainly coincides with urine flow collected from ureter cannula during perfusion. Our present data clearly suggest that in order to clear 99% blood cells out of 10-12 gm rabbit kidneys, at least 3-6 ml of cell free perfusate is required while clearing the whole blood cells out of human kidneys (200-240 gm) may need 600 ml or more. Thus, we recommend that at least 600 ml of perfusate should be used to clear most of the blood cells in the renal vasculature before renal transplantation is performed.
Animal ; Erythrocyte Count ; Erythrocytes/*physiology ; Female ; In Vitro ; Kinetics ; Male ; Models, Biological ; Perfusion ; Rabbits ; *Renal Circulation ; Support, Non-U.S. Gov't