24-hr Urine Research Articles

Solitary plasmacytoma of the uvula

A 64-year-old gentleman presented to an otolaryngologist complaining of feeling a foreign body in his throat for several weeks. He had no pain, no dysphagia, nor odynophagia. In general, he was in good health. On physical exam, a mass could be seen on the posterior aspect of the uvula in the oropharynx (Image 1). A biopsy surprisingly revealed a plasmacytoma, composed of sheets of atypical plasma cells expressing CD56 and CD138 (Image 2). The patient underwent a complete evaluation for plasma cell dyscrasia. Serum electrophoresis with immunofixation revealed a minute lambda band too small to quantify. A 24 hr urine immunofixation revealed no monoclonal proteins. Other studies included normal free serum light chains (kappa-1.06 mg/dL, lambda 1.16 mg/dL ratio 0.9138), Hgb 15.7 g/dL, erythrocyte sedimentation rate 5 MM/hr, Cre 1.13 mg/dL, Albumin 4.3 g/dL, Calcium 9.2 mg/dL. A bone marrow core biopsy and aspirate showed no increase in plasma cells and no evidence of a monoclonal plasma cell population. Skeletal Survey with standard X-rays showed no lytic bone lesions. The patient also underwent a PET-CT scan that showed only the solitary focus in the oropharynx with increased 18F-fluorodeoxyglucose uptake. An MRI of the head showed no other lesions in the nasopharynx or sinuses. Therefore, a diagnosis of Solitary Extraosseous Plasmacytoma (SEP) was made. Treatment consisted of 50Gy of radiation to the lesion on the soft palate and 42.5Gy to the first echelon draining lymph nodes, administered via intensity-modulated radiation therapy (IMRT) to limit toxicity to the parotid gland, sublingual glands, and oral cavity (Image 3). Six weeks postradiation, clinically the lesion had completely regressed, and serum immunofixation no longer detected a minute lambda band. Post treatment PET-CT was negative. He will continue ongoing serologic surveillance and direct laryngoscopy at 3 to 6 month intervals and will be followed indefinitely. In contrast to Osseous (Medullary) Solitary Plasmacytoma, which carries a ∼50% risk of eventually developing Multiple Myeloma, the risk of developing Multiple Myeloma in patients with SEP is lower, estimated at between 10 and 20%. SEP commonly involves the upper respiratory tract and oropharynx as in this case, and has been reviewed extensively 1-6. Currently, the standard treatment approach for SEP is definitive radiation therapy, with a dose of >45 Gy of radiation therapy to the lesion 1, 4. This results in local control rates of ∼90%. Radiation of regional draining lymph nodes has been recommended for lesions involving the soft tissues of the head and neck 2. Patients who continue to display a monoclonal gammopathy post radiation are considered higher risk for either local relapse or eventual evolution to Multiple Myeloma. All patients require close ongoing follow-up.

Iodine Status in Turkish Populations and Exposure to Iodide Uptake Inhibitors

Perchlorate, nitrate, and thiocyanate are competitive inhibitors of the sodium iodide symporter of the thyroid membrane. These inhibitors can decrease iodine uptake by the symporter into the thyroid gland and may disrupt thyroid function. This study assesses iodine status and exposure to iodide uptake inhibitors of non-pregnant and non-lactating adult women living in three different cities in Turkey (Istanbul, Isparta and Kayseri). We measured iodine and iodide uptake inhibitors in 24-hr urines collected from study participants (N = 255). All three study populations were mildly iodine deficient, with median urinary iodine (UI) levels of 77.5 µg/L in Istanbul, 58.8 µg/L in Isparta, and 69.8 µg/L in Kayseri. Perchlorate doses were higher in the study population (median 0.13 µg/kg/day), compared with a reference population (median 0.059 µg/kg/day), but lower than the U.S. EPA reference dose (0.7 µg/kg/day). Urinary thiocyanate levels increased with increasing exposure to tobacco smoke, with non-smokers (268 µg/L) significantly lower than light smokers (1110 µg/L), who were significantly lower than heavy smokers (2410 µg/L). This pilot study provides novel data indicating that study participants were moderately iodine deficient and had higher intakes of the iodide uptake inhibitor perchlorate compared with a reference population. Further investigation is needed to characterize the thyroid impact resulting from iodine deficiency coupled with exposure to iodide uptake inhibitors such as perchlorate, thiocyanate and nitrate.

Estimating 24-hour urine sodium level with spot urine sodium and creatinine.

The 24-hr urine sodium excretion level was estimated based on the spot urine sodium, and the efficacy of the formula was validated to determine the status of low salt intake <100 mEq Na/day. The 24-hr urine samples were collected from 400 patients. The 24-hr urine creatinine level was estimated with the use of three formulas: a newly derived Korean equation (E24UCR_K), and Tanaka (E24UCR_T) and Cockcroft-Gault (E24UCR_CG) equations. The correlation coefficients between the estimated and measured 24-hr urine creatinine for these three equations were 0.863, 0.846, and 0.896, respectively (All P<0.001). After estimating the 24-hr urine sodium levels, the correlation coefficients between the estimated and measured 24-hr urine sodium levels were 0.466, 0.490, and 0.516, respectively (All P<0.001). The sensitivity of three formulas to estimate the measured 24-hr urine sodium≥100 mEq/day using the estimated amount≥100 mEq/day was 84.3%, 87.6%, and 84.8%, respectively. In conclusion, the three equations used to estimate the 24-hr urine sodium content were useful to determine the status of low salt intake.

Analysis of correlation between 24-hour urinary sodium and the degree of blood pressure control in patients with chronic kidney disease and non-chronic kidney disease.

We investigated the association between 24-hr urinary sodium (24UNA) and adequacy of blood pressure (BP) control in patients with chronic kidney disease (CKD) and nonCKD. All data were collected retrospectively by accessing the electrical medical records in patients with 24-hr urine collection and serum creatinine. Enrolled 400 subjects were subgrouped by the amount of 24UNA, or CKD stage. The appropriate BP was defined as BP < 130/80 mmHg for subjects with proteinuria, and BP < 140/90 mmHg for subjects without proteinuria. The mean level of 24UNA was 166±76 mEq/day. The 24UNA group was an independently related factor to diastolic BP as a continuous variable. The rate of appropriate BP control in patients with proteinuria was highest in 24UNA <100 mEq/L (P=0.012). The odds to fail achievement of BP target in subjects with 24UNA≥90 mEq/day was 2.441 (1.249-4.772, P=0.009) higher than that of 24UNA <90 mEq/day among participants with proteinuria. There was difference in the amount of 24UNA between CKD and non-CKD except each stage of CKD group. In conclusion, salt intake estimated by 24-hr urine sodium excretion is a risk factor to achieve appropriate BP control.

Urinary sodium excretion has positive correlation with activation of urinary renin angiotensin system and reactive oxygen species in hypertensive chronic kidney disease.

It is not well described the pathophysiology of renal injuries caused by a high salt intake in humans. The authors analyzed the relationship between the 24-hr urine sodium-to-creatinine ratio (24HUna/cr) and renal injury parameters such as urine angiotensinogen (uAGT/cr), monocyte chemoattractant peptide-1 (uMCP1/cr), and malondialdehyde-to-creatinine ratio (uMDA/cr) by using the data derived from 226 hypertensive chronic kidney disease patients. At baseline, the 24HUna/cr group or levels had a positive correlation with uAGT/cr and uMDA/cr adjusted for related factors (P<0.001 for each analysis). When we estimated uAGT/cr in the 24HUna/cr groups by ANCOVA, the uAGT/cr in patients with ≥200 mEq/g cr was higher than in patients with <100 mEq/g cr (708 [95% CI, 448-967] vs. 334 [95% CI, 184-483] pg/mg cr, P=0.014). Similarly, uMDA/cr was estimated as 0.17 (95% CI, 0.14-0.21) pM/mg cr in patients with <100 mEq/g cr and 0.27 (95% CI, 0.20-0.33) pM/mg cr in patients with ≥200 mEq/g cr (P=0.016). During the 16-week follow-up period, an increase in urinary sodium excretion predicted an increase in urinary angiotensinogen excretion. In conclusion, high salt intake increases renal renin-angiotensin-system (RAS) activation, primarily, and directly or indirectly affects the production of reactive oxygen species through renal RAS activation.

Blood Pressure and Dietary Related Risk Factors Associated with High Sodium Intake Assessed with 24-hour Urine Analysis for Korean Adults

Objectives: This study was conducted to examine blood pressure and other characteristics of a high sodium intake group assessed with 24-hr urine analysis and the dietary factors related to the risk of high sodium intake among Korean adults. Methods: A cross-sectional study was conducted with adults aged 20-59 years. Subjects who completed 24-hr urine collection (N = 205) were divided into 3 groups (tertile) according to the sodium intake estimated with 24-hour urine analysis. We compared the blood pressure, BMI and dietary related factors of the 3 groups (low, medium, high sodium intake group) with General Linear Model (GLM) and Duncan's multiple range test (p 14% (OR = 3.99; 95% CI: 1.404- 6.841). The dietary attitude related to increased risk of high sodium intake included 'enjoy dried fish and salted mackerel' (p < 0.001) and 'eat all broth of soup, stew or noodle' (p < 0.001). Conclusions: Because high sodium intake was associated with higher blood pressure, nutrition education should focus on alcohol consumption, emphasis on related dietary factors such as using low salt soybean paste, improvements in the habit of eating dried fish and salted mackerel or eating all broth of soup, stew or noodle. Korean J Community Nutr 19(6): 537~549, 2014

Estimated amount of 24-hour urine sodium excretion is positively correlated with stomach and breast cancer prevalence in Korea.

Stomach cancer is one of the most common cancers in Korea. The aim of this study was to identify the association between the prevalence of cancer, particularly stomach cancer, and the amount of 24-hr urine sodium excretion estimated from spot urine specimens. The study included 19,083 subjects who took part in the Korean National Health and Nutritional Examination Survey between 2009 and 2011. The total amount of urine sodium excreted in a 24-hr period was estimated by using two equations based on the values for spot urine sodium and creatinine. In subjects who had an estimated 24-hr urine sodium excretion of more than two standard deviations above the mean (group 2), the prevalence of stomach cancer was higher than in subjects with lower 24-hr sodium excretion (group 1). By using the Tanaka equation to estimate it, the prevalence of stomach cancer was 0.6% (114/18,331) in group 1, whereas it was 1.6% (9/568) in group 2 (P=0.006). By using the Korean equation, the prevalence was 0.6% (115/18,392) in group 1, and 1.6% in group 2 (8/507) (P=0.010). By using the Tanaka equation, breast cancer in women is more prevalent in group 2 (1.9%, 6/324) than group 1 (0.8%, 78/9,985, P=0.039). Higher salt intake, as defined by the estimated amount of 24-hr urine sodium excretion, is positively correlated with a higher prevalence of stomach or breast cancer in the Korean population.

Can the adrenergic system be implicated in the pathophysiology of bladder pain syndrome/interstitial cystitis? A clinical and experimental study

To evaluate sympathetic system activity in bladder pain syndrome/interstitial cystitis (BPS/IC) patients and to investigate if chronic adrenergic stimulation in intact rats induces BPS/IC-like bladder modifications. Clinical study--In BPS/IC patients and aged and body mass index matched volunteers TILT test was undertaken and catecholamines were measured in plasma and 24 hr urine samples. Experimental study--Phenylephrine was injected subcutaneously (14 days) to female Wistar rats. Pain behavior, spinal Fos expression, urinary spotting, number of fecal pellets expelled, frequency of reflex bladder contractions, and urothelial height were analyzed. Urothelium permeability was investigated by trypan blue staining. Immunoreactivity against caspase 3 and bax were studied in the urothelium and against alpha-1-adrenoreceptor and TRPV1 in suburothelial nerves. Mast cell number was determined in the sub-urothelium. In rats with lipopolysaccharide-induced cystitis, urinary catecholamines, and Vesicular Monoamine Transporter 2 (VMAT2) expression in bladder nerves were analyzed. The TILT test showed an increase of sympathetic activity. Noradrenaline levels in blood at resting conditions and in 24-hr urine samples were higher in BPS/IC patients. Phenylephrine administration increased visceral pain, spinal Fos expression, bladder reflex activity, urinary spotting and the number of expelled fecal pellets. The mucosa showed urothelial thinning and increased immunoreactivity for caspase 3 and bax. Trypan blue staining was only observed in phenylephrine treated animals. Suburothelial nerves co-expressed alpha1 and TRPV1. Mastocytosis was present in the suburothelium. Cystitis increased sympathetic nerve density and urinary noradrenaline levels. Excessive adrenergic stimulation of the bladder may contribute to the pathophysiological mechanisms of BPS/IC.

Effect of a Novel Nuclear Factor-κB Activation Inhibitor on Renal Ischemia-Reperfusion Injury

In kidney transplantation, the relationship between prolonged warm or cold ischemic storage of kidneys and a higher incidence of delayed graft function is previously known, and delayed graft function has been known to aggravate poor long-term graft survival. We investigated the effect of a novel nuclear factor-κB activation inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on renal ischemia-reperfusion (I/R) injury. DHMEQ was administered to Lewis rats once just before renal artery clamping (DHMEQ pretreatment group), and the effect on I/R injury was investigated. In the DHMEQ pretreatment group, the 24-hr urine volume on days 1 to 3 after I/R was significantly larger, and the protein concentration of the urine on days 2 to 7 was significantly smaller than in the untreated group. The serum creatinine level was significantly improved, and significantly lower levels of the inflammatory cells and inflammatory cytokines were present in the kidneys on day 1. The relative ratio of nuclear to cytoplasmic nuclear factor-κB and oxidative stress of kidney tissue on day 1 were significantly decreased. Treatment with DHMEQ before renal artery clamping may therefore be useful for renal I/R injury and application to renal transplantation is expected.

Autologous Stem Cell Transplantation Improves Survival For High Risk Cardiac Amyloidosis

Cardiac involvement in light chain amyloidosis (AL) predicts poor prognosis and is associated with higher treatment related mortality and morbidity during autologous stem cell transplantation (ASCT). We studied the outcomes of AL patients with cardiac involvement undergoing ASCT at our center between January 2002 and December 2012.Out of a total of 264 AL patients, 53 patients had cardiac involvement according to the International Consensus Criteria (Gertz M et al. AJH 2005) and 27 underwent ASCT. Cardiac staging was assessed using the Revised Prognostic Staging System for Light Chain Amyloidosis (Kumar S et al, JCO 2012). Hematologic and cardiac responses were evaluated before and at 1 year after ASCT using the guidelines established by the 10th International Symposium on Amyloid and Amyloidosis (Gertz M et al. AJH 2005).The median age of the patients was 53 years (range 36-74) with a median duration from diagnosis to ASCT of 6 months (range 3-95). The estimated median follow up for the entire cohort was 41 months (range 6-173). Twenty-four patients (89%) had an additional organ involvement, besides heart. Cardiac stage ≥3 was seen in 14 patients. The median troponin-T, Troponin-I, BNP and NT-proBNP levels and free light chain difference (FCL-diff) were 0.054 ng/ml, 0.05 ng/ml, 376 pg/ml, 1888 pg/ml, and 116.4 mg/l respectively (table1). Twenty-four patients (89%) received induction chemotherapy and 22 of those (81%) received novel chemotherapy agents. Eighteen patients (66.6%) achieved at least PR prior to ASCT. Four patients (14.8%) received reduced doses melphalan conditioning (140-180 mg/m2). One-year transplant related mortality (TRM) was 3.7% (1 patient died at day 11 post-transplant due to cardiac event). At 1-year post ASCT, overall HR was seen in 24 patients (89%) (CR=26% and PR=63%) while 3 patients (11%) had cardiac responses. At the time of last follow up, 17 patients (63%) were alive. The median overall survival (OS) from diagnosis and from ASCT was 58 months (95% CI; 46-69) and 46 months (95% CI; 36-55) respectively (figure1). The median progression free survival (PFS) was 25 months (95% CI; 6-44). Cumulative incidence of hematologic relapse at 3 year was 38.5% (95%CI 23.7-62.5). Cardiac progression at last follow up was seen in 1 patient (3.7%). Negative factors affecting OS included lack of induction therapy prior to ASCT and NT-proBNP more than 5000 pg/ml. We conclude that ASCT is well tolerated in patients with high-risk cardiac amyloidosis and the incorporation of induction therapy can improve overall outcomes of these patients. [Display omitted] Table1Patient CharacteristicsBaseline characteristicsTotal (N=27)Interquartile rangeMedian age (year)5336-71Gender: male (%)20 (74.1)Median time from diagnosis to transplant, (month)63-95Receive induction chemotherapy (%)24 (88.9)Receive novel induction chemotherapy (%)22 (81.5)Light chain type (%)-Kappa-Lambda.6 (22.2) 21 (77.8)Other organ involvement (%)24 (88.9)History of cardiac complications prior ASCT (%)17 (63)History of cardiac complications after ASCT (%)20 (74.1)ICU admission prior ASCT (%)3 (11.1)Cardiac event prior ASCT (%)17 (62.9%)Median FLC-diff (mg/l) (N=15)116.415-1168Median EF (%) (N=19)6030-82Median IVS (mm.) (N=14)1.350.7-2.1Median Troponin-T (ng/ml) (N=20)0.0190.01-0.22Median Troponin-I (ng/ml) (N=19)0.060.03-9.09Median BNP (pg/ml) (N=23)37615.2-1782Median NT-proBNP (pg/ml) (N=12)1888.519-9911Median serum calcium (mg/dl)9.27-11Median serum albumin (g/dl)3.92.4Median Creatinine (mg/dl)1.01-9Median B2 microglobulin (mg/l)3.151-15Median 24-hr urine protein (mg)574120-36006Median serum M protein (g/dl)0.50-4Median LDH (IU/l)377146-770Median BM plasma cell (%)110-58Cardiac stage at diagnosis.Stage 11Stage 25Stage 36Stage 48Cardiac stage at transplant.Stage 13Stage 25Stage 34Stage 46 Disclosures:No relevant conflicts of interest to declare.

The optimal duration of frequency‐volume charts related to compliance and reliability

To assess Frequency-volume charts (FVCs) for the yield of additional recorded days and the ideal duration of recording related to compliance and reliability. Of 500 consecutive urologic outpatients willing to complete a 7-day FVC, 378 FVCs were evaluable. During seven consecutive days every voiding time and volume were recorded. Missed entries were indicated with a coded letter, thereby assessing the true frequency and compliance. Reliability is the agreement of the day-to-day FVC parameters with the 7-day FVC pattern. Single-day reliability was assessed and used in the Spearman-Brown formula. FVCs of 228 male and 150 females were evaluated. Mean age was 55.2 years (standard deviation [SD]: 16.2 years), and mean 24-hr urine production was 1,856 ml (SD: 828 ml). The percentage of patients with complete FVCs decreased from 78% on day 2 to 58% on day 7, and dropped below 70% after 4 days. Single-day reliability was r = 0.63 for nocturnal urine production, r = 0.72 for 24-hr urine production, and r = 0.80 for mean voided volume. At 5 days, reliability of 90% was achieved for all parameters. With each additional day, FVCs showed a decrease in compliance and an increase in reliability. At day 3, reliability of 80% was achieved for all FVC parameters, but compliance dropped to 73%. Beyond 5 days, the yield of additional recorded days was limited. We advocate an FVC duration of 3 days, but the duration may be shortened or extended depending on the goal of the FVC.

Variability of Organophosphorous Pesticide Metabolite Levels in Spot and 24-hr Urine Samples Collected from Young Children during 1 Week

Background: Dialkyl phosphate (DAP) metabolites in spot urine samples are frequently used to characterize children’s exposures to organophosphorous (OP) pesticides. However, variable exposure and short biological half-lives of OP pesticides could result in highly variable measurements, leading to exposure misclassification. Objective: We examined within- and between-child variability in DAP metabolites in urine samples collected during 1 week. Methods: We collected spot urine samples over 7 consecutive days from 25 children (3–6 years of age). On two of the days, we collected 24-hr voids. We assessed the reproducibility of urinary DAP metabolite concentrations and evaluated the sensitivity and specificity of spot urine samples as predictors of high (top 20%) or elevated (top 40%) weekly average DAP metabolite concentrations. Results: Within-child variance exceeded between-child variance by a factor of two to eight, depending on metabolite grouping. Although total DAP concentrations in single spot urine samples were moderately to strongly associated with concentrations in same-day 24-hr samples (r ? 0.6–0.8, p &lt; 0.01), concentrations in spot samples collected &gt; 1 day apart and in 24-hr samples collected 3 days apart were weakly correlated (r ? –0.21 to 0.38). Single spot samples predicted high (top 20%) and elevated (top 40%) full-week average total DAP excretion with only moderate sensitivity (? 0.52 and ? 0.67, respectively) but relatively high specificity (? 0.88 and ? 0.78, respectively). Conclusions: The high variability we observed in children’s DAP metabolite concentrations suggests that single-day urine samples provide only a brief snapshot of exposure. Sensitivity analyses suggest that classification of cumulative OP exposure based on spot samples is prone to type 2 classification errors.

Abstract 304: The Role of Calcitonin Gene Related Peptide (CGRP) in Cardiovascular Regulation and Blood Vessel Structure

Calcitonin gene related peptide (CGRP) is known to be a potent microvascular dilator and hypotensive agent. This peptide and its receptors are distributed widely in both central and peripheral nervous systems. CGRP-containing neural fibers are closely associated with blood vessels in the arterial circulation where its release leads to vascular dilation. However, its role in cardiovascular regulation remains controversial. We studied the hemodynamic and autonomic function, as well as blood vessel structure in CGRP knockout (KO) mice. Blood pressure (BP), heart rate (HR) and activity level were assessed at least one week after mice were implanted with telemeters. Ten CGRP KO and ten wild type (WT) mice (4-5 month old) were used in this study. After the recording period, 24-hr urine and blood were collected for assessment of catecholamines and their metabolites. To study the baroreflex sensitivity, phenylephrine and sodium nitroprusside were administered in an acute study with seven mice from each group. We found no significant difference in 24-hr mean arterial pressure (MAP) (105.0 ± 1.8mmHg, vs. 112.1 ± 3.1mmHg, p= 0.05) between the two groups. There was also no difference in HR (KO: 566.4 ± 12.1; WT: 581.9 ± 8.5, p = 0.31). Norepinephrine was greatly elevated in both plasma and 24-hr urine in KO mice (in urine: KO: 956 ± 91 pg/ml, WT: 618 ± 46pg/ml, p = 0.004; in plasma: KO: 2505 ± 596pg/ml, n=6, WT: 1168 ± 98 pg/ml, p = 0.04). Paradoxically, cardiovagal baroreflex sensitivity was higher in the KO mice (KO: 3.2 ± 0.7 ms/mmHg, n=7, WT: 1.4 ± 0.3 ms/mmHg, n=7, p=0.03). Thoracic aortas were collected from both groups to measure vessel stiffness. The diameter at 125 mmHg of the aorta was significantly smaller in CGRP KO mice than in WT (321±30μm, vs. 422±82μm, p&lt;0.01). Therefore, we hypothesize that although CGRP may have a limited contribution to physiological cardiovascular regulation, it may play a significant role in modulating the vagal tone and the structure properties of blood vessels.

Abstract 452: The Degree of Nephron Deficit is a Determinant of the Cardiovascular and Renal Risks Associated With a Reduced Nephron Endowment

A reduced nephron endowment is associated with an increased sensitivity to hypertensive stimuli. We examined whether nephron endowment, and the degree of nephron deficit, impacts on the blood pressure and renal response to chronic angiotensin II (AngII) infusion. To address this aim we used the GDNF heterozygous mouse that, despite the same genotype, produces two distinct levels of nephron deficit due to the role of GDNF in both the initiation of kidney development and induction of nephron formation. GDNF het mice are born with either 2 small kidneys and a 30% nephron deficit (Het2K), or a single small kidney (Het1K) and a 65% nephron deficit compared to wild-type littermates (WT). Sixteen week old male GDNF WT (n=9), Het2K (n=5) and Het1K (n=7) mice were implanted with radiotelemetry probes and baseline pressures recorded. Mice were administered enalapril (10mg/kg/day, drinking water) alone for 3 days, then concomitant with an AngII infusion (600ng/kg/min; s.c. osmotic minipump) for a further 21 days. 24hr albumin and urine excretion were assessed at baseline and at the end of the 21 days of blood pressure recording. Baseline MAP was not different between WT, Het2K and Het1K groups (98.3±1.3, 97.1±1.8, 100.9±1.9mmHg respectively). Enalapril treatment led to a similar fall in MAP of 23mmHg in the 3 groups before the commencement of AngII infusion. AngII led to an immediate rise in MAP in all groups. At the end of the 21day infusion period, MAP of WT and Het2K mice were similar (122±3.3, 120.5±6.1mmHg), but MAP of Het1K mice (139.7±3.6mmHg; P&lt;0.01) was significantly elevated over WT mice. Albumin excretion was not different between the groups at baseline, and AngII infusion did not significantly increase albumin excretion in WT or Het2K mice. However albumin excretion in Het1K mice increased 15 fold (4.86±1.56 to 76.05±30.3ug/24hr; P&lt;0.001). Urine excretion also significantly increased in the Het1K (1.59±1.5 to 3.7±0.59ml/24h; P&lt;0.001) in response to Angiotensin II, though WT and Het2k mice were not affected. AngII infusion in Het1K, but not Het2k mice, led to significant exacerbation of hypertension and albuminuria. Our data suggests that the degree of nephron deficit is an important determinant of the risks associated with a reduced nephron endowment.

Abstract 506: Effects of High Salt Diet on Urine and Sodium Excretion in Db/db Mice

Cardiovascular diseases are among the complications of diabetes mellitus. People with hypertension are encouraged to reduce salt intake. Our working hypothesis is that diabetes will not cause sodium retention in the presence sodium load. This study was carried out to evaluate the role of diabetes in pressure diuresis and natriuresis. Diabetic mice (db/db-/-) 5 week old adult (37-49 g) male and diabetic were purchased from Jackson Laboratory, Bar Harbor, ME, USA. The db/db phenotype spontaneously develops characteristics of type 2 diabetes including obesity, hyperinsulinemia, and insulin resistance. The animals were randomly divided into groups (n=5-6 per group) and assigned to normal rat chow (0.5% NaCl diet) or high salt diet (8% NaCl from Research Diets, Inc. New Brunswick, NJ, USA), for 7 weeks. Renal function was determined by measuring urine volume (Uv), urinary and sodium (UNav). Metabolic cages were used in collecting 24-hr urine samples. Urinary sodium was measured using flame photometer. There were no significant differences in urine volumes collected on Day 1 in high salt and normal salt-fed db/db-/- mice. Urinary volumes (ml) of 26.7±8.1, 18.7±3.9, 28.0±3.5 of high salt-fed mice and 22.5±4.7, 18.2±5.9, 26.0±4.2 of normal salt-fed mice were collected in weeks 1, 3 and 7. The observed weekly increase in urine volume was significant in each group, but not significant between the two groups. Urinary sodium (μmol/ 24 hr) of 16.6±7.1, 22.8±4.1, 66.1±21.3 of high salt-fed mice and 1.0±0.2, 12.5±3.4, 3.5±0.1 of normal salt-fed mice were collected in weeks 1, 3, and 7. There were significant weekly increases in sodium excretion in high salt diet only. From our observation, sodium was excreted significantly. Therefore, sodium retention may not be a contributory factor to the incidence of hypertension in diabetes. There is need for further investigations on the complications of diabetes in relation to cardiovascular events such as hypertension.

Abstract 273: Increased Blood Pressure and Proteinuria and Absence of Increased Nitric Oxide (NO) Production During Pregnancy in the Dahl Salt Sensitive (S) Rat

In normal pregnancy, systemic vasodilation due to increased NO production allows a drop in blood pressure (BP) despite increased volume retention. Little is known about the pathogenesis of preeclampsia, defined by increased BP and proteinuria, due to a lack of animal models that spontaneously develop the disease. Here we tested the hypothesis that the Dahl S rat, a genetic model of hypertension and kidney disease, is also a spontaneous model of preeclampsia. Female Dahl S rats were implanted with a telemetry unit, and baseline BP was recorded. Rats were placed in metabolic cages for 24 hr urine collection while on a low nitrate diet, and urinary protein and NO metabolite concentrations were measured via Bradford and Greiss assays, respectively. There were no differences in baseline BP (152±1 vs 151±4 mmHg) or proteinuria (61±10 vs 60±17 mg/d) in the rats selected for mating vs virgin rats (n=5-7). Pregnancy was confirmed by presence of sperm (day 1). Measurements were made during mid and late pregnancy (days 10-11, 17-18), and terminal measurements were taken on day 19. Pregnant rats exhibited an increase in BP and proteinuria with no change in urinary NOx excretion (Table), while no changes were observed in age-matched virgin rats. Kidney cortex abundance of neither NOS1 nor NOS3 was increased at late pregnancy; however, plasma concentration of the endogenous NOS inhibitor ADMA was increased in late pregnant compared to virgin rats (0.82±0.06 vs. 0.62±0.06 μM, p&lt;0.05). These data suggest that the Dahl S rat cannot upregulate NO production during pregnancy; therefore, this relative NO deficiency may contribute to worsening hypertension and proteinuria during pregnancy in this strain.

Abstract 155: Group IV Cytosolic Phospholipase A 2 a Disruption Protects Against Angiotensin II-Induced Hypertension and End Organ Damage

Previously we have shown that Group IV cytosolic phospholipase A 2 α (cPLA 2 α) is critical for the development of angiotensin (Ang) II-induced hypertension, cardiovascular dysfunction and fibrosis. This study was conducted to determine the role of cPLA 2 α in renal dysfunction and end organ damage associated with Ang II-induced hypertension. Eight weeks old male wild type (cPLA 2 α +/+ ) and cPLA 2 α knockout (cPLA 2 α -/- ) mice were infused with Ang II (700 ng/kg/min) or its vehicle for 2 weeks and systolic blood pressure (SBP) was measured weekly by the tail cuff method. Ang II increased SBP (mmHg) in cPLA 2 α +/+ mice to a greater degree than in cPLA 2 α -/- mice (125 ± 2 to 186 ± 7 vs. 125 ± 2 to 132 ± 2 respectively, P&lt; 0.05). Ang II caused renal fibrosis as indicated by accumulation of α-smooth muscle actin, transforming growth factor-β-positive cells and collagen deposition in the kidneys of cPLA 2 α +/+ but not cPLA 2 α -/- mice. Ang II infusion increased reactive oxygen species production in the kidney measured by 2-hydroxyethidium fluorescence (AU), in cPLA 2 α +/+ mice (16.14 ± 0.61 vehicle vs. 24.08 ± 0.61 Ang II P &lt; 0.05) but not in cPLA 2 α -/- mice (16.93 ± 0.58 vehicle vs. 17.19 ± 0.93 Ang II). Mice were placed in metabolic cages to monitor their water intake and urine output. After 13 days of Ang II infusion, 24 hr water intake was increased (4.33 ± 0.14 ml to 8.17 ± 0.27 ml P &lt; 0.05) in cPLA 2 α +/+ mice but not in cPLA 2 α -/- mice (4.87 ± 0.22 ml to 4.8 ± 0.27 ml). Twenty-four hr urine output (μl) was increased to a greater extent in cPLA 2 α +/+ mice (423.33 ± 67.26 to 2030.94 ± 191.58 P &lt; 0.05) vs. cPLA 2 α -/- mice (374.37 ± 66.89 to 787.37 ± 126.50). Urine osmolality (mOsm/kg) was decreased (3778.33 ± 240.21 to 1620 ± 129.23 P &lt; 0.05) in cPLA 2 α +/+ but not in cPLA 2 α -/- mice (4042 ± 306.07 to 3372.5 ± 43.27), and proteinuria (mg/24hr) increased to a greater extent in cPLA 2 α +/+ mice (2.07 ± 0.11 to 6.99 ± 0.34 P &lt; 0.05) vs. cPLA 2 α -/- mice (1.95 ± 0.07 to 3.03 ± 0.20 in cPLA 2 α -/- ). These data suggest that cPLA 2 α contributes to Ang II-induced hypertension, associated renal dysfunction and end organ damage, most likely due to release of arachidonic acid, activation of NADPH oxidase and generation of ROS. Thus, cPLA 2 α could serve as a potential therapeutic target in the treatment of hypertension and end organ damage.

Abstract 383: Hypertensive and Renal Injury Responses to Angiotensin II and High Salt Intake in Mice Lacking the Gene for Interleukin-10

Endogenous interleukin-10 (IL-10) exerts immune down-regulating action on the generation of tumor necrosis factor-alpha (TNF-α). The present study examined the hypothesis that IL-10 plays a protective role in hypertension and renal injury induced by angiotensin II (AngII) and high salt (HS) diet by minimizing TNF-α production. Systemic blood pressure (BP; monitored by implanted radio-telemetry), TNF-α level in plasma and in the kidney (by ELISA) as well as renal injury (glomerulosclerosis, GS by PAS staining and renal interstitial fibrosis, RIF by Trichrome staining) responses to chronic infusion of AngII (400 ng/min; osmotic minipump) for 2 wks were evaluated in wild-type (WT; n=11) and IL-10 gene knockout mice (KO; n=11) which were fed either normal (NS; 0.03% NaCl, n=5) or HS (4% NaCl; n=6) diets. On the last day of the experiment, a 24 hr urine collection was made using metabolic cages prior to sacrificing the mice for the collection of plasma and renal tissue samples. The mean baseline BP in KO was lower (104±3 vs 116±4 mmHg) than that in WT. Increase in BP in AngII+HS treated KO was lower (Δ 20±5 vs Δ 39±2 mmHg) than that in WT but similar in AngII+NS treated KO and WT (Δ 40±3 vs Δ 47±7 mmHg). In AngII+HS treated WT, TNF-α was higher in plasma (69±6 vs 34±4 pg/mL) and in renal tissue (208±15 vs 95±11 pg/mg protein) compared to values in WT treated with AngII+NS. In AngII+HS treated KO, TNF-α was lower in plasma (20±3 vs 180±44 pg/mL) and in renal tissue (205±23 vs 277±23 vs pg/mg protein) compared to values in KO treated with AngII+NS. The urinary nitrate/nitrite excretion rate was higher in AngII+NS (0.56±0.25 vs 0.08±0.01 mM/24 hr) and AngII+HS (1.23±0.12 vs 0.18±0.02 mM/24 hr) treated KO compared to the correspondingly treated WT. The eNOS protein expression was higher in KO treated with AngII+NS (~2 folds) or AngII+HS (~3 folds) compared to those in treated WT. GS (24.6±1.3 vs 13.8±2.1 %) and RIF (10.6±1.1 vs 7.8±0.5 %) changes were greater in AngII+NS treated KO than those in treated WT. However, the changes were minimal in HS treated groups. In conclusion, these data demonstrate that there exists an interaction of IL-10 and eNOS activity in the regulation of TNF-α in the kidney that provides a protective role by minimizing hypertension and renal injury induced by Ang II and HS intake.

Abstract 233: Resistance Training Attenuates Renal Dysfunction in Animal Diabetic Nephropathy but Does Not Restore Kidney ACE/ACE2 Balance

Overactivity of the intrarenal renin-angiotensin system (RAS) has been implicated in the pathogenesis of diabetic nephropathy. Our group has already demonstrated that aerobic exercise reduces kidney angiotensin II levels and attenuates renal dysfunction under concurrence of diabetes and hypertension. Resistance training (RT) has recently been recognized as a useful therapeutic tool for the treatment chronic diseases and similar to aerobic exercise, has been reported to improve glycemic control. Therefore, the aim of this study was to evaluate the effect of RT on renal function and RAS in diabetic animals, to understand whether this type of exercise is also associated with renoprotection. Wistar rats (3 months old) were randomized into: sedentary control (SC); trained control (TC); sedentary diabetic (SD) and trained diabetic (TD). Animals were made diabetic with a single tail injection of streptozotocin (STZ, 50 mg/Kg). RT was performed on an 110-cm ladder (8 ladder climbs, once/day, 5 days/week, 8 weeks), carrying a load of 50-80% body weight (BW) appended to the tail. At week 8, 24 hr urine volume and albuminuria were evaluated. Kidney was excised and ACE and ACE2 activities were determined (ZPhe-HL and 7-Mca-APK(Dnp), respectively) (Two way ANOVA + Tukey test; P&lt;0.05). RT significantly reduced blood glucose (TD = 449 ± 17 vs. SD = 572 ± 18 mg/dL) and attenuated BW loss of diabetic animals. DM reduced renal ACE activity in sedentary and trained groups (SD = 3.72 ± 0.48, TD = 3.85 ± 0.40 vs. SC = 9.2 ± 0.59 nmol/min/mg), while RT reduced enzyme activity only in control group (TC = 5.14 ± 0.26 vs. SC = 9.2 ± 0.59 nmol/min/mg). RT reduced renal ACE2 in the control group compared to the others (TC = 0.05 ± 0.0001 vs. SC = 0.09 ± 0.004, SD = 0.09 ± 0.003, TD = 0.10 ± 0.002 μM/min/mg), with no effect of diabetes on enzyme activity. RT improved renal function, decreasing urinary volume and albuminuria (DT = 4.13 ± 0.84 vs. SD = 11 ± 2.11 mg/24h) in DT group. The results from the present study show that RT is strongly associated with renoprotection in an experimental model of diabetic nephropathy. Moreover, results show that this improvement on renal function is modulated by other pathways apart from ACE and ACE2 converting enzymes. Financial Support: FAPESP, CAPES, CNPq.

Abstract 295: Sodium Restriction Increases Ophthalmic Artery Systolic Velocity in Healthy Subjects

Changes in ocular blood flow occur in systemic diseases. A high peak systolic velocity (PSV) in the ophthalmic artery (OA) has been observed in diabetes mellitus and hypertension, conditions often associated with high tissue renin-angiotensin system (RAS) activity and reduced renal plasma flow (RPF). Since our group has demonstrated that sodium restriction ( a high RAS state ) is associated with a decrease in RPF which is correctable with ACE inhibition, we hypothesized that sodium restriction would result in higher ophthalmic PSV. Sixteen healthy volunteers (age 46.2±13.2, male 69%, white 75%, BMI 26±3.7) were placed on a low sodium (LS) diet (10 mmol/day) for 1 week followed by high sodium (HS) diet (200 mmol/day). Sodium balance was assessed by 24hr urine collection. BP, RPF (PAH clearance) and OA hemodynamic measurements (Multigon, NY) were made after overnight fasting and rest in the supine position. Sodium restriction did not affect BP (systolic/diastolic LS: 121/73 ± 12/7 vs HS: 122/72 ± 15/9 mmHg, mean ± SD, NS) or heart rate (69 ± 16 vs 70 ± 15/min, NS). As expected, RPF was lower on LS compared with HS (599.2 ± 89.8 vs 633.4 ± 93.5ml/min/1.73 m 2 , p=0.006). Sodium restriction was associated with higher OA peak (38.8 ± 6.4 vs 33.2 ± 6.0 cm/sec, p=0.018) and mean (19.7±2.9 vs 17.1±3.5, p=0.003) systolic velocity ( Figure ). There was no change in end-diastolic velocity (10.6±2.5 vs 9.7±2.4, p=0.266) with sodium restriction. In conclusion, sodium restriction was associated with an increase in OA peak and mean systolic velocity in healthy individuals. Further studies are required to investigate the potential relevance of our results to diabetic and hypertensive retinopathy.