Dietary sodium restriction reduces blood pressure in patients with treatment resistant hypertension.

Purpose: Patients with treatment resistant hypertension (TRH) are at particular risk of cardiovascular disease. Life style modification, including sodium restriction, is an important part of the treatment of these patients. We aimed to analyse if self-performed dietary sodium restriction could be implemented in patients with TRH and to evaluate the effect of this intervention on blood pressure (BP).

Does conservative kidney management offer a quantity or quality of life benefit compared to dialysis? A systematic review.

Background: Patients with stage 5 chronic kidney disease (CKD5) collaborate with their clinicians when choosing their future treatment modality. Most elderly patients with CKD5 may only have two treatment options: dialysis or conservative kidney management (CKM). The objective of this systematic review was to investigate whether CKM offers a quantity or quality of life benefit compared to dialysis for some patients with CKD5.

Estimation of renal perfusion based on measurement of rubidium-82 clearance by PET/CT scanning in healthy subjects.

Background: Changes in renal blood flow (RBF) may play a pathophysiological role in hypertension and kidney disease. However, RBF determination in humans has proven difficult. We aimed to confirm the feasibility of RBF estimation based on positron emission tomography/computed tomography (PET/CT) and rubidium-82 (Rb) using the abdominal aorta as input function in a 1-tissue compartment model.

Effect of amiloride and spironolactone on renal tubular function, ambulatory blood pressure, and pulse wave velocity in healthy participants in a double-blinded, randomized, placebo-controlled, crossover trial.

We wanted to test the hypothesis that treatment with amiloride or spironolactone reduced ambulatory (ABP) and central blood pressure (CBP) and that tubular transport via ENaCγ and AQP2 was increased after furosemide treatment. During baseline conditions, there were no differences in ABP, CBP, renal tubular function, or plasma concentrations of vasoactive hormones. After furosemide treatment, an increase in CBP, CH(2)o, FE(Na), FE(K), u-AQP2/min, u-ENaCγ/min, PRC, p-Ang II, and p-Aldo was observed.

Abnormal increase in urinary aquaporin-2 excretion in response to hypertonic saline in essential hypertension.

Background: Dysregulation of the expression/shuttling of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in renal collecting duct principal cells has been found in animal models of hypertension. We tested whether a similar dysregulation exists in essential hypertension.

Methods: We measured urinary excretion of AQP2 and ENaC β-subunit corrected for creatinine (u-AQP2(CR), u-ENaC(β-CR)), prostaglandin E2 (u-PGE2) and cyclic AMP (u-cAMP), fractional sodium excretion (FE(Na)), free water clearance (C(H2O)), as well as plasma concentrations of vasopressin (AVP), renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), and atrial and brain natriuretic peptide (ANP, BNP) in 21 patients with essential hypertension and 20 normotensive controls during 24-h urine collection (baseline), and after hypertonic saline infusion on a 4-day high sodium (HS) diet (300 mmol sodium/day) and a 4-day low sodium (LS) diet (30 mmol sodium/day).

Urinary excretion of AQP2 and ENaC in autosomal dominant polycystic kidney disease during basal conditions and after a hypertonic saline infusion.

Renal handling of sodium and water is abnormal in chronic kidney diseases. To study the function and regulation of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in autosomal dominant polycystic kidney disease (ADPKD), we measured urinary excretion of AQP2 (u-AQP2), the β-subunit of ENaC (u-ENaC(β)), cAMP (u-cAMP), and prostaglandin E(2) (u-PGE(2)); free water clearance (C(H2O)); fractional sodium excretion (FE(Na)); and plasma vasopressin (p-AVP), renin (p-Renin), angiotensin II (p-ANG II), aldosterone (p-Aldo), and atrial and brain natriuretic peptide (p-ANP, p-BNP) in patients with ADPKD and healthy controls during 24-h urine collection and after hypertonic saline infusion during high sodium intake (HS; 300 mmol sodium/day) and low sodium intake (LS; 30 mmol sodium/day). No difference in u-AQP2, u-ENaC(β), u-cAMP, u-PGE(2), C(H2O), and vasoactive hormones was found between patients and controls at baseline, but during HS the patients had higher FE(Na).

Protein-enriched diet increases water absorption via the aquaporin-2 water channels in healthy humans.

Background: According to animal experiments, a protein-enriched diet increased renal absorption of sodium and water. We wanted to test the hypothesis that a protein-enriched diet would increase the expression of the aquaporin-2 water channels and the epithelial sodium channels in the distal part of the nephron using biomarkers for the activity of the two channels.

Methods: We performed a randomized, placebo controlled crossover study in 13 healthy humans to examine the effect of a protein-enriched diet on renal handling of water and sodium during baseline condition and during hypertonic saline infusion.

Effects of dihydralazine on renal water and aquaporin-2 excretion in humans.

Objective: Dihydralazine is a vasodilator that lowers blood pressure, but often also leads to significant water and sodium retention. To characterize the effect of dihydralazine on renal sodium and water handling, we tested the hypothesis that dihydralazine causes water retention parallel with an increase in urinary excretion of aquaporin-2 (u-AQP2) in healthy humans.

Material And Methods: The effect of intravenous infusion of dihydralazine in three doses (3.