High-phosphorus diet controlled for sodium elevates blood pressure in healthy adults via volume expansion.

Whether increasing exposure to dietary phosphorus can lead to adverse clinical outcomes in healthy people is not clear. In this open-label prospective cross-over study, we are to explore the impact of various dietary phosphorus intake on mineral, sodium metabolisms and blood pressure in young healthy adults. There were 3 separate study periods of 5 days, each with a 5 days washout period between different diets interventions. Six young healthy male volunteers with normal nutrition status were recruited in Phase I Clinical Research Center and sequentially exposed to the following diets: (a) normal-phosphorus diet (NPD): 1500 mg/d, (b) low-phosphorus diet (LPD): 500 mg/d, (c) high-phosphorus diet (HPD): 2300 mg/d. HPD induced a significant rise in daily average serum phosphate (1.47 ± 0.02 mmol/L [4.56 ± 0.06 mg/dl]) compared to NPD (1.34 ± 0.02 mmol/L [4.15 ± 0.06 mg/dL]) and LPD (1.17 ± 0.02 mmol/L [3.63 ± 0.06 mg/dL]) (p < .05). Daily average levels of serum parathyroid hormone and fibroblast growth factor 23 in HPD were significantly higher, and serum 1,25(OH)2 D3 was remarkably lower than those in LPD. HPD induced a significant decrease in daily average serum aldosterone and an increase in daily average atrial natriuretic peptide level compared to LPD. The 24-hour urine volume in HPD subjects was less than that in LPD subjects. HPD significantly increased daily average systolic blood pressure by 6.02 ± 1.24 mm Hg compared to NPD and by 8.58 ± 1.24mm Hg compared to LPD (p < .05). Our study provides the first evidence that 5-day high-phosphorus diet can induce elevation in SBP in young healthy adults, which may due to volume expansion.

Aqueous extract of Astragali Radix ameliorates proteinuria in adriamycin nephropathy rats through inhibition of oxidative stress and endothelial nitric oxide synthase.

AIM OF THE STUDY: To investigate the effects of aqueous extract of Astragali Radix (ARE) on the oxidative stress status and endothelial nitric oxide synthase level in adriamycin (ADR) nephropathy rats. MATERIALS AND METHODS: ADR nephropathy rats were randomly treated with ARE (2.5 g/kg/d, n=6, ARE group), or benazepril (10mg/kg/d, n=6, angiotensin-converting enzyme inhibitor (ACEI) group) for ten weeks. Serum urea nitrogen, creatinine, albumin, total protein, cholesterol and 24-h urinary protein concentration were determined. Renal cortex catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), malondialdehyde (MDA) activities, and 24-h urinary NO(3)(-)/NO(2)(-) excretion were determined by chromatometry. Renal cortex cyclic guanosine monophosphate (cGMP) level was measured by enzyme immunoassay and eNOS expression was determined by immunohistochemistry. RESULTS: ARE and ACEI treatments could remarkably reduce more 24h urinary protein excretion than that in ADR group (88.32±9.96 mg, 81.78±16.28 mg vs. 153.91±28.63 mg, P<0.01), and there was no difference between ARE and ACEI group. Renal cortex CAT, GSH-Px activities in ARE and ACEI group were significantly higher than ADR group, and renal cortex SOD activity in ARE group was higher than ADR group. Renal cortex MDA activity, cGMP level, and glomerular and tubular eNOS expression in ARE and ACEI group were lower than that in ADR group, and 24-h urinary NO(3)(-)/NO(2)(-) excretion in ARE group was lower than ADR group. Renal cortex MDA content (r=0.895, P<0.01), cGMP content (r=0.666, P<0.01) and eNOS expression in glomerulus (r=0.910, P<0.01) were strongly positively associated with 24h urinary protein excretion. And renal cortex SOD content was negatively associated with 24h urinary protein excretion (r=-0.861, P<0.01). CONCLUSIONS: ARE may ameliorate the proteinuria by suppressing the over expression of eNOS, and inhibiting the oxidative injury in ADR nephropathy rats.

Effects of HELP therapy on acute ischemic stroke and vascular endothelial cell function.

To evaluate the therapeutic effects of the HELP system (heparin-induced extracorporeal low-density lipoprotein-apolipoprotein(a)-fibrinogen precipitation) in patients with acute ischemic stroke and probe into its possible mechanism, 10 patients with acute ischemic stroke were included in this study and received the HELP therapy in addition to low molecular weight dextran, salvia miltiorrhiza and aspirin. Matched with gender, age, European Stroke Scale (ESS) and fibrinogen, 20 patients with cerebral infarction treated with low molecular heparin were chosen as controls during the same period. We compared the efficacy and prognosis between the two groups. In order to clarify the effects of HELP treatment on endothelial function, human umbilical vein endothelial cells (HUVEC) were cultured with the serum of pre- and post-HELP therapy and control patients, then endothelial permeability and biomarkers of endothelial dysfunction or activation in the supernatant of incubated HUVEC, such as soluble thrombomodulin (sTM), soluble intracellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1), were tested. Twenty-one days after treatment, ESS scores in the HELP group (70.4 +/- 23.06) were higher than those in control group (60.7 +/- 18.94), but there was no statistical significance (P > 0.05). In the HELP group, total efficacy rate reached 60% with ESS score (6 cases of recovery and efficacy, 4 cases of inefficacy), while it was 40% in control group (8 cases of recovery and efficacy, 12 cases of inefficacy), but unfortunately there was no significant difference between both groups using the chi(2)-test (P > 0.05). Interestingly, with the activities of daily living (ADL) score, the efficacy rate in the HELP group (60%) was markedly higher than that in the control group (20%) (P < 0.05). Furthermore, Pearson correlation analysis showed that the therapeutic window (the time from the patient's onset to receiving the therapy) was correlated to final ADL scores (P = 0.044) and the mean therapeutic window was 14.08 +/- 3.41 h in patients who achieved efficacy criteria. After therapy, no difference was found in hemorheology, fibrinogen, blood lipid, oxidized low-density lipoprotein (oxLDL) or C-reactive protein (CRP) in the control group, while there was a significant decrease in the HELP group immediately after treatment (P < 0.01). But the hospital stay time was similar between the HELP group and the controls (23.11 +/- 10.65 vs. 21.53 +/- 8.73 days; P > 0.05) and 21 days later, the dimension of the largest cross-sectioned infarction area by CT scan did not significantly change for the two groups' of patients (P > 0.05). When cultured with the patient's serum after HELP therapy, the concentration of sTM, sICAM-1, and MCP-1 in the supernatant of cultured HUVEC remained unchanged at 24 h (P > 0.05), while it was remarkably higher when HUVEC was cultured with the serum of the controls and patients before HELP therapy (P < 0.01), except for sTM. The endothelial permeability was also improved after the HELP treatment. With the effects of improving hemorheology, decreasing acute phase reactive proteins such as CRP and fibrinogen, ameliorating endothelial cell function, HELP system may be a novel therapy for acute ischemic stroke.