Renal Blood Flow Velocity Research Articles

Indole-3-carboxaldehyde alleviates cisplatin-induced acute kidney injury in mice by improving mitochondrial dysfunction via PKA activation

Cisplatin (DDP) is widely used in the treatment of cancer as a chemotherapeutic drug. However, its severe nephrotoxicity limits the extensive application of cisplatin, which is characterized by injury and apoptosis of renal tubular epithelial cells. This study aimed to reveal the protective effect and its underlying mechanism of Indole-3-carboxaldehyde (IC) against DDP-induced AKI in mice and NRK-52E cells pretreated with PKA antagonist (H-89). Here, we reported that IC improved renal artery blood flow velocity and renal function related indicators, attenuated renal pathological changes, which were confirmed by the results of HE staining and PASM staining. Meanwhile, IC inhibited the levels of inflammatory factors, oxidative stress, CTR1, OCT2, and the levels of autophagy and apoptosis. Mitochondrial dysfunction was significantly improved as observed by TEM. To clarify the potential mechanism, NRK-52E cells induced by DDP was used and the results proved that H-89 could blocked the improvement with IC effectively in vitro. Our findings showed that IC has the potential to treat cisplatin-induced AKI, and its role in protecting the kidney was closely related to activating PKA, inhibiting autophagy and apoptosis, improving mitochondrial function, which could provide a theoretical basis for the development of new clinical drugs.

The clinical application of ultrasound for acute kidney injury during sepsis-from macroscopic to microscopic renal perfusion perspectives

The aim was to quantify macroscopic renal blood flow and renal cortical microcirculation in patients with septic acute kidney injury (AKI) using ultrasound and contrast-enhanced ultrasound. In this case-control study, patients in the intensive care unit diagnosed with septic AKI were divided into stages 1-3 based on the 2012 KDIGO (Kidney Disease: Improving Global Outcomes) AKI diagnostic criteria. The patients were categorized into mild (stage 1) and severe (stages 2 and 3) groups, while septic patients without AKI served as the control group. Ultrasound parameters such as macrovascular renal blood flow and time-averaged velocity, as well as cardiac function parameters such as cardiac output and cardiac index, were measured. The time-intensity curve in the microcirculation was analyzed through contrast-enhanced ultrasound imaging software to calculate imaging parameters such as peak time, rise time, fall half-time and mean transit time of the interlobar arteries in the renal cortex. In terms of macrocirculation, renal blood flow and time-averaged velocity decreased gradually with the progression of septic acute renal injury (p=0.004, p < 0.001). There was no difference in cardiac output and cardiac index values among the three groups (p=0.17 and p=0.12). In terms of microcirculation, ultrasonic Doppler parameters of the renal cortical interlobular artery, such as peak intensity, risk index and ratio of peak systolic velocity to end-diastolic velocity, gradually increased (all p values <0.05). The temporal contrast-enhanced ultrasound parameters-time to peak, rise time, fall half-time and mean transit time-were prolonged in AKI groups when compared with the control group (p < 0.001, p=0.003, p=0.004 and p=0.009, respectively). In patients with septic AKI, the renal blood flow and time average velocity of macrocirculation in the kidneys are reduced, while the time parameters of microcirculation such as time to peak, rise time, fall half-time and mean transit time are prolonged, especially in patients with severe AKI. These changes are not related to changes in cardiac output or cardiac index.

Abstract 10045: Higher Renal Vascular Resistance is Associated With Greater Body Mass Index in Children

Background: Obesity is associated with increased risk for cardiovascular and renal diseases, however, there has been little focus on renal vascular function. The purpose of this study is to assess renal vascular flow regulation and investigate their relation to cardiovascular risk factors in obese children. Methods: Noninvasive ultrasonographic measurements were made in 108 overweight/obese children aged 7 to 13 years (body mass index 18 to 33kg/m 2 ). Using color Doppler sonography, peak systolic (PSV), end-diastolic (EDV), and average peak flow (APV) velocities of renal artery were measured. Pulsatility index as a parameter of vascular resistance was calculated. Pulsatility index was defined as (PSV-EDV)/APV. Quantitative B-mode ultrasound scans were used to measure intima-media thickness and diameters of the common carotid artery. Plasma lipid concentrations, uric acid, homeostasis model assessment of insulin resistance, and high sensitivity C-reactive protein were assessed in the obese children. Results: Compared with overweight children with body mass index &lt;25 kg/m 2 , pulsatility index in obese children with body mass index≥25 kg/m 2 was significantly higher (1.24 ±0.13 vs. 1.13 ±0.14 cm/sec, p &lt; 0.01), because APV and EDV were significantly lower (35 ±3 vs. 38 ±7 cm/sec and 21± 3 vs. 25 ±5 cm/sec, p &lt;0.05, respectively), although PSV was not significantly different. Pulsatility index correlated significantly with body mass index (r =0.58, p &lt; 0.01), insulin (r = 0.24, p &lt; 0.05), homeostasis model assessment of insulin resistance (r =0.25, p &lt; 0.01), triglycerides (r = 0.26, p &lt; 0.01), uric acid (r = 0.22, p &lt; 0.05), systolic blood pressure (r = 0.31, p &lt; 0.01), and carotid intima-media thickness (r = 0.36, p&lt;0.01). Renal blood flow velocities did not correlate with high sensitivity C-reactive protein. Conclusions: The present study indicates that obesity can adversely affect renal vascular flow and resistance in children. Obesity-related insulin resistance may be a main risk factor for renal vascular flow changes. Obesity not only is a risk factor for later cardiovascular disease, but also is associated with significant impairment of renal arterial flow dynamics.

Effect of electroacupuncture on renal vascular microcirculation in diabetic mice based on in vivo two-photon microscopy imaging

To investigate the protective effect of electroacupuncture (EA) at "Zusanli"(ST36)and "Weiwanxiashu"(EX-B3) on capillary function around the renal tubule and renal tubule structure in diabetic mice based on two-photon microscopy (TPM) imaging, so as to providing visualizable evidence for the regulatory effect of EA on diabetic renal vascular microcirculation. Spontaneous type Ⅱ diabetes mellitus mice (db/db) were employed for this study. Twenty db/db mice were randomly divided into model group (n=10) and EA group (n=10), and 10 db/m mice used as the control group. EA was applied to bilateral ST36 and EX-B3 for 20 min/time, 6 times a week for 6 weeks. The body weight was recorded and the fasting blood glucose measured before and after the intervention. The urine production and water consumption of mice in each cage were recorded after EA. The renal in vivo imaging method based on TPM was established to display the morphological structure of renal tubules, and the mouse renal blood flow velocity was detected by injecting 500 kDa dextran-fluorescein into femoral vein after the intervention. Compared with the control group, the proportion of mice with decreased body mass in the model group was increased, accounting for 40%, while that in the control group was 0%; and fasting blood glucose, urine production and water consumption were significantly increased in the model group (P<0.001, P<0.000 1). A renal in vivo imaging method based on TPM was successfully established, which can be applied to quantitatively analyze the renal blood flow and renal tubular diameter of mice. Based on this method, the results showed that compared with the control group, the blood flow velocity of peritubular capillary in the model group was significantly decreased (P<0.000 1, P<0.001), renal tubular cells were slightly exfoliated and the diameter of renal tubular was significantly increased (P<0.000 1). Compared with the model group, EA reduced the body weight loss ratio from 40% to 0%, and significantly decreased the fasting blood glucose, urine production and water consumption (P<0.01, P<0.000 1, P<0.001), and the blood flow velocity of peritubular capillary in the EA group was significantly increased (P<0.001, P<0.05) and tubule dilatation significantly alleviated (P<0.0 1). EA at ST36 and EX-B3 can ameliorate renal vascular microcirculation disorder to relieve the renal structure damage and improve renal function in diabetes mice.

Cerebral and renal hemodynamics: similarities, differences, and associations with chronic kidney disease and aortic hemodynamics.

Elevated arterial pulsatility is a common risk factor for cerebrovascular disease and chronic kidney disease (CKD), which suggests that the brain and kidneys may have similar hemodynamic profiles. The objectives of this study were twofold: 1) to compare and contrast the cerebral and renal blood flow parameters in adults without CKD (hereafter, non-CKD adults) and CKD patients and 2) to determine the common predictor(s) of cerebral and renal hemodynamics among pressure pulsatility and several cardiovascular risk factors. In 110 non-CKD adults and 66 CKD patients, cerebral and renal blood flow velocity (BFV) were measured by transcranial Doppler and Duplex ultrasonography, respectively. Pulsatile hemodynamics were assessed by the pulsatility (PI) and resistive (RI) indices. Aortic pulse pressure was measured by tonometry. Compared with non-CKD adults, CKD patients showed greater pulsatility of the BFV (i.e., systolic minus diastolic BFV), PI, and RI in the kidneys but not the brain. However, the cerebral and renal PI and RI values were strongly correlated in both non-CKD adults (both PI and RI values: rs = 0.695) and CKD patients (both PI and RI values: rs = 0.640) (all P < 0.001). Multiple linear regression analysis further demonstrated that the cerebral and renal PI and RI associations remained significant after adjustment for potential covariates (e.g., age, sex, thepresence of CKD). The aortic pulse pressure was a significant predictor for both cerebral and renal PIand RI values. Collectively, our findings suggest that CKD patients have higher renal flow pulsatility, which is strongly and independently associated with cerebral flow pulsatility and aortic hemodynamics.

Effect of high-intensity interval exercise on renal artery hemodynamics in healthy young adults.

High-intensity interval exercise is useful for sustained exercise; however, its effect on renal artery hemodynamics is unclear. This study aimed to evaluate changes in renal artery blood flow velocity due to high-intensity interval exercise. Ten healthy adults (age, 23.5±1.2 years) completed high-intensity interval exercise and moderate-intensity continuous exercise protocols on separate days. The high-intensity interval exercise protocol (total duration, 26 min) comprised eight sets of high-intensity exercise sessions at 85% maximum oxygen uptake for 1 min, with intervals of 40% maximum oxygen uptake for 2 min between sets. The moderate-intensity continuous exercise protocol comprised 40 min of exercise at 40% maximum oxygen uptake. Renal artery blood flow velocity and natural log-transformed high frequency spectral power (an index of cardiac parasympathetic nervous system activity) were measured before and after exercise. Additionally, exercise enjoyment was measured using a questionnaire. Renal artery blood flow velocity did not significantly differ between protocols or timepoints for either protocol. However, the natural log-transformed high frequency spectral power was significantly lower with high-intensity interval exercise than with moderate-intensity continuous exercise (P<0.001, F=25.97) during exercise and at 10 min after exercise, and it did not return to pre-exercise levels with high-intensity interval exercise. Moreover, there was no significant difference in exercise enjoyment between the two protocols. In healthy young adults, high-intensity interval exercise reduces parasympathetic activity; however, it does not produce any significant changes in renal artery hemodynamics after exercise.

Evaluation of Renal Oxygenation and Hemodynamics in Patients with Chronic Kidney Disease by Blood Oxygenation Level-dependent Magnetic Resonance Imaging and Intrarenal Doppler Ultrasonography

Introduction: The basic pathophysiologic derangement of chronic kidney disease (CKD) begins with the loss of nephrons, leading to renal hemodynamic changes, eventually causing a reduced nephron count and renal hypoxia. The purpose of this study was to observe the renal oxygenation and renal hemodynamics of patients with CKD using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) and intrarenal Doppler ultrasonography (IDU). Methods: The study enrolled 39 patients with stage 1–4 CKD and 19 healthy volunteers (HVs). Based on their estimated glomerular filtration rate (eGFR), CKD patients were divided into 2 subgroups: a mild renal impairment (MI) group and a moderate to severe renal impairment (MSI) group. We monitored the participants’ mean cortical T2* (COT2*) and mean medullary T2* (MET2*) values on BOLD-MRI, and measured the peak systolic velocities (PSVs), end-diastolic velocities (EDVs), renal resistive index (RI), and kidney length by IDU. We also recorded clinical indicators such as age, sex, body mass index (BMI), 24-h urinary protein (24-h Upr), serum creatinine (sCr), blood urea nitrogen (BUN), and eGFR. BOLD-MRI, IDU measurements, and the clinical indicators were compared in CKD patients and HVs by the analysis of variance and Kruskal-Wallis H test. Spearman’s correlation was used to assess the relationship between data from BOLD-MRI and IDU and clinical indicators. Results: The COT2* values were significantly higher than the MET2* values in the HV, MI, and MSI groups. COT2*, MET2*, EDV, PSV, and kidney length gradually decreased in the HV, MI, and MSI groups (all p < 0.05), whereas RI and 24-h Upr gradually increased (both p < 0.05). Spearman correlation analysis showed that COT2* and MET2* were significantly positively correlated with eGFR, PSV, EDV, and kidney length but were significantly negatively correlated with sCr, BUN, and 24-h Upr (all p < 0.05). There was no correlation observed between the COT2* and MET2* and the RI and BMI values. Conclusions: Renal oxygenation and blood flow velocities were found declined as the CKD stage progressed. The BOLD-MRI and IDU techniques may have clinical value by measuring intrarenal oxygenation and renal blood perfusion to judge the severity of renal damage in patients with CKD.

Possible Protective Effect of Endothelin-1 Receptor Antagonist on Renal Impairment in Type 2 Diabetic Rats

Background: Diabetic nephropathy (DN) is characterized by persistent albuminuria and progressive decline in glomerular filtration rate (GFR). Bosentan is a non-peptide mixed antagonist of ET-1. Aim: To investigate the possible protective role of bosentan on renal impairment in T2DM rats and the mechanisms concerned. Materials: Fifty rats were randomly divided into five equal groups; Non-Diabetic (ND), Diabetic non-treated (DN), Diabetic Bosentan-treated (D-Bos.), Diabetic Metformin-treated (D-Met.), Diabetic combined Bosentan and Metformin-treated groups (D-Bos& Met.). T2DM was induced by Streptozotocin (STZ) (35mg/kg) and high fat diet (HFD) for 3 weeks. Both Bosentan and metformin were given orally for 4 weeks. At the end of the experiment, 24hrs urine samples were collected to measure urine (volume, albumin, NAG and creatinine), renal blood flow velocity (RBFV) and peripheral renal resistance (RVR) were measured using Doppler technique. Blood was collected directly from abdominal aorta to estimate fasting serum glucose, glycosylated hemoglobin (HBA1c), serum insulin, complete lipid profile, renal function tests and parameters of oxidative stress: malondialdehyde (MDA), total antioxidant capacity (TAC) and tumor necrosis factor-α (TNFα). Insulin resistance, serum LDL-cholesterol, urinary albumin creatinine ratio (UACR) and creatinine clearance (CC) were calculated. Results: Serum cysteine c, BUN, urinary albumin and UACR were significantly lowered in both D-Bos. & D-Met when compared to the corresponding values in DN while urinary volume, urinary creatinine, CC and RBFV were significantly elevated but serum creatinine, NAG & RVR were significantly lowered in D-Bos. only. Conclusion: Bosentan and metformin treatment both have a renoprotective effect. Combined treatment showed better results.

Vascular effects of combined vacuum interferential therapy in patients with urolithiasis after extracorporeal shock wave lithotripsy

To study the combined vacuum-interference therapy effect on the renal blood flow in patients with urolithiasis after ECSWL. Forty patients aged 33 to 64 years old with urolithiasis after ECSWL were included in the study. Patients were assigned into two groups by simple randomization. Starting the second day after ECSWL, along with drug therapy, the patients of the main group (n=20) received vacuum-interference therapy with the carrier frequency of 5 kHz, frequency range 80-150 Hz, and the vacuum of 0.3-0.4 bar for 15 min daily, 6-8 procedures in total. Patients in the control group (n=20) received antibacterial and anti-inflammatory drug therapy, the same as the main group. To evaluate the severity of impaired renal blood flow due to nephrolithotripsy, we studied renal blood flow by the basic hemodynamic characteristics of renal ultrasound dopplerography (USDG): renal blood flow indices at the level of renal, segmental, interlobar, and arch arteries, including measurement of systolic linear blood flow velocity (Vps) and diastolic blood flow velocity (Vsd), as well as pulsatility index (PI) and resistance index (RI). The ultrasound examination prior to ECSWL revealed a statistically significant increase in all studied parameters. Thus, Vsd in renal arteries was increased by 32.7% (p<0.01) and 17.8% (p<0.05), respectively; in segmental arteries by 14.5% (p<0.05) and 29.5% (p<0.05), respectively; in interlobar arteries by 14.5% (p<0.05) and 29.5% (p<0.05), respectively, and in the arcus arteriosus by 10.7% (p<0.05) and 21.4% (p<0.05), respectively; the renal vein blood flow was within the reference range. When assessing PI in UL patients before lithotripsy, a statistically significant increase in all studied indices was also observed: in the renal arteries by 19.0% (p<0.05), in the segmental arteries by 12.5% (p<0.05), and in the interlobar and arch arteries by 11.6% (p<0.05) and 11.8% (p<0.05), respectively. After the treatment course, the most pronounced change was observed in the patients of the main group, in which all indices differed from the reference values only by 3.5-8.3%. It is important to note an increase in linear velocity in the renal vein by 21.4% (p<0.05), indicating a significant improvement of renal blood flow due to improved venous outflow and increased arterial inflow in the renal arteries. In the control group patients, statistically significant improvement was observed only for systolic and diastolic blood flow velocity, as well as the renal vein blood flow velocity, which increased by 22.1% (p<0.05), 6.3% and 17.8% (p<0.05), respectively; the other parameters remained unchanged. When assessing PI and RI values after the treatment course, the most marked improvement was also observed in the main group of patients, in which all indices were close to the reference values (p<0.05). In the control group patients, the indices were 11.6-14.0% higher than reference values (p<0.05). According to obtained data, it was concluded that vacuum interference therapy has a pronounced vascular effect that promotes an earlier recovery of blood flow and normalization of the kidney function in patients with urolithiasis after extracorporeal lithotripsy and can be recommended for routine clinical practice.

Effects of aldose reductase inhibitors on renal blood flow parameters in patients with early diabetic nephropathy

ObjectiveTo investigate the changes of renal blood flow parameters in patients with early-stage diabetic nephropathy (DN) treated with Aldose reductase inhibitors (ARI)/Epalrestat. MethodsIn this prospective, 120 early DN patients aged 20–75 years from the Endocrinology Department of Chengyang District People's Hospital of Qingdao City in 2015 were randomized to intervention group including 68 patients and control group including 52 patients. Two groups of patients separately received Epalrestat and placebo for 3 months. Renal vascular parameters and blood biochemical index were collected at baseline and after intervention. ResultsAfter 3 months of supplementation, Epalrestat significantly improved the renal and segmental renal arterial end-diastolic blood flow velocity (EDV) and the interlobular artery peak systolic blood flow velocity (PSV) compared with placebo. While Epalrestat markedly decreased the blood flow resistance index (RI) in interlobular artery compared to placebo. There were no significant changes in fasting blood glucose (FBG), diastolic blood pressure (DBP), systolic blood pressure (SBP), serum urinary acid (SUA), low-density lipoprotein cholesterol (LDL), triacylglycerol (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL), waist circumference (WC) and body mass index (BMI). ConclusionEpalrestat can effectively improve renal arterial blood flow and renal arterial perfusion, which play a protective role in early DN.

Ketidaksesuaian Dosis dan Interval Pemberian Antibiotik pada Lansia di Bangsal Penyakit Dalam RSUD dr Moewardi Solo serta Gambaran Timbulnya Efek Samping yang Merugikan

Aging causes a decrease in renal blood flow velocity and clearance values ​​related to renal filtration function. A decrease in kidney filtration function results in a decrease in the ability of drug elimination so that the drug and its metabolites tend to accumulate in the blood. The dose of certain antibiotics must be adjusted to the patient's kidney function. Clinical estimates of kidney filtration function are expressed in terms of creatinine clearance (CrCl). This study aims to determine the percentage of suitability of the dose and interval of antibiotic administration with the CrCl value of elderly patients and to see description of the side effects arising from the administration of antibiotics.&#x0D; This research was observational with data retrospective retrieval of medical records. The subjects of the study were elderly patients who were hospitalized in the ward ward in dr. Moewardi Solo Hospital in the period January - May 2019 , ≥ 60 years aged with a diagnosis of Pneumonia, Urinary Tract Infection (UTI), Cellulitis and sepsis with complete medical record data. The antibiotics evaluated are all antibiotics given to the patient while being treated.&#x0D; The results showed the suitability of the dose and interval of antibiotic administration with the CrCl value of elderly patients hospitalized in the disease ward in RSUD Dr. Moewardi Solo for the period January-May 2019 was 63.35%, the incidence of side effects arising from the administration of antibiotics was nausea and vomiting (10 patients ) and diarrhea (4 patients).

Wavelet Coherence as a Tool for Visualizing the Relationship between Glomerular Filtration Rate and Renal Artery Blood Flow Velocity

Wavelet Coherence as a Tool for Visualizing the Relationship between Glomerular Filtration Rate and Renal Artery Blood Flow Velocity

The association between NIRS and Doppler ultrasonography in preterm infants with patent ductus arteriosus

Objective: To determine if near-infrared spectroscopy (NIRS), which is easier to obtain than Doppler ultrasonography (USG), may be used in accordance with Doppler USG to provide additional data for assessment of organ blood flow velocities in preterm infants with hemodynamically significant PDA.Study design: Thirty-one infants who were treated with ibuprofen for closure of PDA were monitored continuously with NIRS. Cerebral, mesenteric, and renal arterial blood flow velocities were measured with Doppler USG before and after the treatment.Results: While cerebral, mesenteric, and renal fractional oxygen extraction (FTOE) measurements decreased significantly (p = .042, p < .001, p < .001, respectively), NIRS measurements (p = .016, p < .001, p < .001, respectively) and mean blood flow velocities (p = .003, p = .011, p = .002, respectively) increased significantly after the treatment. There was a significant correlation between pretreatment cerebral and mesenteric FTOE and resistive index (RI) values (r = 0.45, p = .01, and r = 0.46, p = .01, respectively). However, no correlation was observed between renal FTOE values and renal RI (r = 0.33, p = .06). Posttreatment cerebral, renal, and mesenteric FTOE values correlated positively with corresponding RI (r = 0.41, p = .02; r = 0.39, p = .02; r = 0.65, p < 01; respectively). Pretreatment and posttreatment cerebral, mesenteric, and renal FTOE values and arterial mean velocities were inversely correlated (pretreatment: r = 0.69, p < .01; r = 0.72, p < .01; r = 0.77, p < .01; posttreatment: r = 0.54, p = .01; r = 0.69, p < .01; r = 0.38, p = .01; respectively).Conclusion: As Doppler and NIRS measurements correlated significantly, we concluded that NIRS might be used in monitoring organ blood flow in preterm infants with PDA, which may provide additional data for management of this condition.

Age and Gender-Related Changes in Renal Haemodynamics of Albino Rats: The Possible Role of Cytokines and Prostaglandins

AbstractBackground: The normal aging process leads to changes in kidney morphology, hemodynamics and function, which are influenced by several factors, including gender. Females develop less age-dependent loss of renal function due to cardiorenal protective effects of estrogens.Aim of Study: The aim of this study was to elucidate the age and gender-related changes in some renal haemodynamics in albino rats with special focusing on the role of cytokines and prostaglandins in establishment of such changes.Material and Methods: Sixty albino rats (30 males & 30 females) of local strain were divided into 2 major groups (Group I of male rats and Group II of female rats) was further subdivided into 3 subgroups: Young (4wk), young adult (3mo) and old (25mo). Body Weight (BW) and absolute Kidney Weight (KW) were measured. The Systolic Blood Pressure (SBP) of the rats was measured by the rat-tail plethysmography technique using a tail-cuff sphygmomanometer. The Renal Blood Flow Velocity (RBFV) and Renal Vascular Resistance (RVR) were measured using bi-directional blood flow meter with FFT-analysis. The blood samples were collected after a period of overnight fasting, left to be clotted, centrifuged and serum was separated for measurement of serum testosterone in male rats, serum estrogen in female rats, creatinine clearance, serum IL1beta, IL6 and serum PGE.Results: The aging of male rat group is accompanied by change in the renal hemodynamic and some blood measure-ments. This is represented by significant increase in systolic blood pressure, renal vascular resistance, serum PGE, serum interleukin1-b & 6, impaired renal function and significant decrease of renal blood flow. It was observed that the old female group had decreased in estrogen hormone level, which led to increase in systolic blood pressure, renal vascular resistance, serum PGE, serum interleukin1-b & 6 and signif-icant decrease renal blood flow.Conclusion: Aging has a significant influence in renal hemodynamic (decrease of renal blood flow and increase of renal vascular resistance) and also, serum interleukin1-b & 6 have a role in this change accompanied with pathophysiology of aging. Female is more protected from complications of the kidney aging than male due to the previous effect of estrogen hormone.

Hemodynamics of infants with strong fluctuations of internal cerebral vein.

There is a high incidence of intraventricular hemorrhage in extremely low-birthweight (ELBW) infants of low gestational age with high-grade fluctuations in the perfusion waveform of the internal cerebral vein. This study investigated changes in the hemodynamic status of ELBW infants during initial strong fluctuations in the perfusion waveform of the internal cerebral vein. We evaluated the perfusion waveform of the internal cerebral vein in 192 ELBW infants from birth, every 8h for a total of 120h. Sixty-seven infants had high-grade fluctuations. On the basis of the presence of patent ductus arteriosus (PDA), patients were subdivided into PDA(-) (n=32) and PDA(+) (n=35) groups. During the first high-grade fluctuation, the PDA(-) group had significant increases in systolic, diastolic, and mean blood pressure (P<0.001 for all). The PDA(+) group did not have significant changes in blood pressure but did have significant increases in the number of interruptions or regurgitations of diastolic renal arterial blood flow (P=0.04) and end-diastolic left pulmonary arterial flow velocity (P<0.001), indicating increased left-to-right shunt. Blood pressure elevation may underlie fluctuations in the perfusion waveform of the internal cerebral vein and lead to the first high-grade increases during acute management of ELBW infants. When no elevation in blood pressure occurred, hemodynamically significant PDA was considered a potential underlying factor.

КАРДИОРЕНАЛЬНЫЕ ВЗАИМОСВЯЗИ ПРИ ХРОНИЧЕСКОЙ ОБСТРУКТИВНОЙ БОЛЕЗНИ ЛЁГКИХ

The aim is to study the interrelationships between the state of pulmonary, intracardiac hemodynamics and renal blood flow in patients with chronic obstructive pulmonary disease (COPD) complicated with the chronic cor pulmonale (CCP). 75 patients with COPD complicated with compensated CCP who had the study of pulmonary, intracardiac and renal hemodynamics with the method of ultrasound duplex scanning were examined. The patients were divided into 2 groups: the 1st group included 45 patients with COPD with pulmonary hypertension (PH) without clinical signs of right ventricle insufficiency; the 2nd group included 30 patients with COPD and PH complicated with right ventricle insufficiency. It was found out that the patients with COPD alongside with the progression of the disease and development of the heart insufficiency had an increase of renal vessel resistance (p&lt;0.01) and a decrease of the velocity of renal blood flow (p&lt;0.001). In the first group of patients there was found a consistent correlation between the increase of the vessel resistance in renal arteries and growth of general peripheral vessel resistance (p&lt;0.001), of systolic pressure in the pulmonary artery (p&lt;0.001) and diastolic dysfunction of the left ventricle (LV) (p&lt;0.001), suggested the influence of these predictors on the velocity of the arterial blood flow in kidneys. In the 2nd group there was registered a strong correlation between the decrease of ejection fraction (EF) of LV and the increase of pulsation and resistive indices of arcuate arteries (r=0.69; p&lt;0.01 and r=0.71; p&lt;0.01, respectively), as well as the increase of end-diastolic volume, end-systolic volume of LV and speed parameters of the renal blood flow at all levels (r=0.67; p&lt;0.01). The study of the relationship between the parameters of hemodynamics of the right ventricle (RV) and the state of the renal blood flow revealed a consistent correlation between the decrease of EF of RV and the decrease of diastolic rate at all levels of renal arteries (p&lt;0.001), the increase of resistive (p&lt;0.01) and pulsation indices (p&lt;0.01) of the arterial system of kidneys. These correlations reflect a negative influence of both a left ventricle and right ventricle insufficiency on the state of the renal blood flow.

Renal Medullary Oxygenation Decreases in a Dose‐Dependent Manner with Graded Lower Body Negative Pressure in Healthy Young Adults

BackgroundIncrease in sympathetic nerve activity (SNA) evokes a renal vasoconstrictor response that is powerfully opposed by autoregulatory influences. In the renal medulla, increases in SNA serve to increase Na+/K+‐ATPase activity (an oxygen dependent process) in the distal tubule, a process contributing to salt and water retention. In this report, we engaged SNA with lower body negative pressure (LBNP) as we employed magnetic resonance imaging to examine an index of renal medullary oxygenation, T2*. At a separate time we applied LBNP as we measured changes in renal blood flow velocity. This is an index that largely reflects changes in renal cortical blood flow.MethodsThirteen healthy (mean age 28 ± 1 yr) men (n = 7) and women (n = 6) participated in one or both of the experimental visits. Graded negative pressure (−10, −20, and −30 mmHg) was applied during 2 visits; visit 1 was for Doppler and visit 2 for MRI. Blood pressure (BP) and heart rate (HR) were also measured at baseline and at each stage of LBNP and recovery. RBV was obtained in all 13 subjects while T2* was obtained in 8 of 13 subjects.ResultsLBNP −30 mmHg led to a lower T2* (−0.65 ± 0.14 ms; P &lt; 0.001). RBV decreased and renal vascular resistance (RVR) increased at −30 mmHg (ΔRBV −7.44 ± 3.87 cm/s, P = 0.041; ΔRVR arbitrary units 0.28 ± 0.11, P = 0.028). During recovery, T2* remained below baseline for the first and the second minutes of the recovery.ConclusionsThese data suggest that −30 mmHg LBNP leads to renal vasoconstriction and medullary deoxygenation. We suspect that changes in T2* are due to a sympathetically mediated, oxygen requiring, accentuation of Na/K ATP activity in the distal tubule. We postulate that this leads to salt and water retention as the SNS is engaged.Support or Funding InformationCommonwealth Universal Research Enhancement Program (CURE); P01 HL134609 (Sinoway)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Omega-3 polyunsaturated fatty acid supplementation reduces blood pressure but not renal vasoconstrictor response to orthostatic stress in healthy older adults.

Older adults exhibit augmented renal vasoconstriction during orthostatic stress compared to young adults. Consumption of omega‐3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oil (FO), modulates autonomic nerve activity. However, the effect of omega‐3 polyunsaturated fatty acid consumption on the renal vasoconstrictor response to orthostatic stress in young and older adults is unknown. Therefore, 10 young (25 ± 1 years; mean ± SEM) and 10 older (66 ± 2 years) healthy adults ingested 4 g FO daily for 12 weeks, and underwent graded lower body negative pressure (LBNP; −15 and −30 mmHg) pre‐ and post‐FO supplementation. Renal blood flow velocity (RBFV; Doppler ultrasound), arterial blood pressure (BP; photoplethysmographic finger cuff), and heart rate (electrocardiogram) were recorded. Renal vascular resistance (RVR), an index of renal vasoconstriction, was calculated as mean BP/RBFV. All baseline cardiovascular values were similar between groups and visits, except diastolic BP was higher in the older group (P < 0.05). FO supplementation increased erythrocyte EPA and DHA content in both groups (P < 0.05). FO did not affect RVR or RBFV responses to LBNP in either group, but attenuated the mean BP response to LBNP in the older group (older −30 mmHg: pre‐FO −4 ± 1 vs. post‐FO 0 ± 1 mmHg, P < 0.05; young −30 mmHg: pre‐FO −5 ± 1 vs. post‐FO −5 ± 2 mmHg). In conclusion, FO supplementation attenuates the mean BP response but does not affect the renal vasoconstrictor response to orthostatic stress in older adults.

Muscle mechanoreflex activation via passive calf stretch causes renal vasoconstriction in healthy humans.

Reflex renal vasoconstriction occurs during exercise, and renal vasoconstriction in response to upper-limb muscle mechanoreflex activation has been documented. However, the renal vasoconstrictor response to muscle mechanoreflex activation originating from lower limbs, with and without local metabolite accumulation, has not been assessed. Eleven healthy young subjects (26 ± 1 yr; 5 men) underwent two trials involving 3-min passive calf muscle stretch (mechanoreflex) during 7.5-min lower-limb circulatory occlusion (CO). In one trial, 1.5-min 70% maximal voluntary contraction isometric calf exercise preceded CO to accumulate metabolites during CO and stretch (mechanoreflex and metaboreflex; 70% trial). A control trial involved no exercise before CO (mechanoreflex alone; 0% trial). Beat-to-beat renal blood flow velocity (RBFV; Doppler ultrasound), mean arterial blood pressure (MAP; photoplethysmographic finger cuff), and heart rate (electrocardiogram) were recorded. Renal vascular resistance (RVR), an index of renal vasoconstriction, was calculated as MAP/RBFV. All baseline cardiovascular variables were similar between trials. Stretch increased RVR and decreased RBFV in both trials (change from CO with stretch: RVR - 0% trial = Δ 10 ± 2%, 70% trial = Δ 7 ± 3%; RBFV - 0% trial = Δ -3.8 ± 1.1 cm/s, 70% trial = Δ -2.7 ± 1.5 cm/s; P < 0.05 for RVR and RBFV). These stretch-induced changes were of similar magnitudes in both trials, e.g., with and without local metabolite accumulation, as well as when thromboxane production was inhibited. These findings suggest that muscle mechanoreflex activation via passive calf stretch causes renal vasoconstriction, with and without muscle metaboreflex activation, in healthy humans.

Effects of intravenous bolus injection of nicorandil on renal artery flow velocity assessed by color Doppler ultrasound

BackgroundPrevious animal studies have shown that a potassium channel opener, nicorandil, provokes vasodilation in renal microvasculature and increases renal blood flow. We conducted a clinical study that aimed to evaluate the effect of nicorandil on renal artery blood flow in comparison with nitroglycerin by using color Doppler ultrasound. MethodsThe present study enrolled 40 patients with stable coronary artery disease who had no renal arterial stenosis and renal parenchymal disease. The patients received intravenous administration of nicorandil (n=20) or nitroglycerin (n=20). Before and after the administration, renal artery blood flow velocity was measured by color-guided pulsed-wave Doppler. ResultsThe peak-systolic, end-diastolic, and mean renal artery blood flow velocities before the administration were not different between the nicorandil group and the nitroglycerin group. The peak-systolic (79±15cm/s to 99±21cm/s, p<0.001; and 78±19cm/s to 85±19cm/s, p=0.004), end-diastolic (22±5cm/s to 28±8cm/s, p<0.001; and 24±6cm/s to 26±6cm/s, p=0.005) and mean (41±6cm/s to 49±9cm/s, p<0.001; and 43±9cm/s to 45±9cm/s, p=0.009) renal artery flow velocities increased significantly in either group. The nominal changes in the peak-systolic (20±10cm/s vs. 7±8cm/s, p<0.001), end-diastolic (5±4cm/s vs. 2±3cm/s, p=0.001), and mean (8±5cm/s vs. 2±2cm/s, p<0.001) renal artery blood flow velocities were significantly greater in the nicorandil group compared with the nitroglycerin group. ConclusionIntravenous nicorandil increased renal artery blood flow velocity in comparison with nitroglycerin. Nicorandil has a significant effect on renal hemodynamics.