Myriad of factors involved in blood pressure control. Salt intake connects them all.

Long-lasting elevated blood pressure (BP), i.e. hypertension, is a major contributor to morbidity and mortality worldwide.

Sex Dependence in Control of Renal Haemodynamics and Excretion in Streptozotocin Diabetic Rats-Role of Adenosine System and Nitric Oxide.

Recently, we compared an interplay of the adenosine system and nitric oxide () in the regulation of renal function between male normoglycaemic (NG) and streptozotocin-induced diabetic rats (DM). Considering the between-sex functional differences, e.g.

Polymer Biocompositions and Nanobiocomposites Based on P3HB with Polyurethane and Montmorillonite.

Due to the growing interest in biopolymers, biosynthesizable and biodegradable polymers currently occupy a special place. Unfortunately, the properties of native biopolymers make them not good enough for use as substitutes for conventional polymers. Therefore, attempts are being made to modify their properties.

Nonselective and A2a-Selective Inhibition of Adenosine Receptors Modulates Renal Perfusion and Excretion Depending on the Duration of Streptozotocin-Induced Diabetes in Rats.

Long-lasting hyperglycaemia may alter the role of adenosine-dependent receptors (P1R) in the control of kidney function. We investigated how P1R activity affects renal circulation and excretion in diabetic (DM) and normoglycaemic (NG) rats; the receptors' interactions with bioavailable NO and HO were also explored. The effects of adenosine deaminase (ADA, nonselective P1R inhibitor) and P1A2a-R-selective antagonist (CSC) were examined in anaesthetised rats, both after short-lasting (2-weeks, DM-14) and established (8-weeks, DM-60) streptozotocin-induced hyperglycaemia, and in normoglycaemic age-matched animals (NG-14, NG-60, respectively).

Biobased poly(3-hydroxybutyrate acid) composites with addition of aliphatic polyurethane based on polypropylene glycols.

Poly(3-hydroxybutyrate) (P3HB) is the most important of the polyhydroxyalkanoates. It is biosynthesized, biodegradable, biocompatible, and shows no cytotoxicity and mutagenicity. P3HB is a natural metabolite in the human body and, therefore, it could replace the synthetic, hard-to-degrade polymers used in the production of implants.

Role of Ang1-7 in renal haemodynamics and excretion in streptozotocin diabetic rats.

The contribution of angiotensin (1-7) (Ang1-7) to control of extrarenal and renal function may be modified in diabetes. We investigated the effects of Ang1-7 supplementation on blood pressure, renal circulation and intrarenal reactivity (IVR) to vasoactive agents in normoglycaemic (NG) and streptozotocin diabetic rats (DM). In Sprague Dawley DM and NG rats, 3 weeks after streptozotocin (60 mg/kg i.

Thermally stable biopolymer composites based on poly(3-hydroxybutyrate) modified with linear aliphatic polyurethanes - preparation and properties.

Purpose: Poly(3-hydroxybutyrate) (P3HB) is a biopolymer, but storing products from P3HB causes the deterioration of their properties leading to their brittleness. P3HB has also low thermal stability. Its melting point almost equals its degradation temperature.

New Mono- and Diesters with Imidazoquinolinone Ring- Synthesis, Structure Characterization, and Molecular Modeling.

The objective of the studies was to synthesize and characterize new mono- and diesters with an imidazoquinolin-2-one ring with the use of 2,3-dihydro-2-thioxo-1H-imidazo[4 ,5-c]-quinolin-4(5)-ones and ethyl bromoacetate. The products were isolated at high yield and characterized by instrumental methods (IR, H-, C-, and N- NMR, MS-ESI, HR-MS, EA). In order to clarify the places of substitution and the structure of the derivatives obtained, molecular modeling of substrates and products was performed.

Interplay of the adenosine system and NO in control of renal haemodynamics and excretion: Comparison of normoglycaemic and streptozotocin diabetic rats.

The adenosine (Ado) system may participate in regulation of kidney function in diabetes mellitus (DM), therefore we explored its role and interrelation with NO in the control of renal circulation and excretion in normoglycemic (NG) and streptozotocin-diabetic (DM) rats. Effects of theophylline (Theo), a non-selective Ado receptor antagonist, were examined in anaesthetized NG or in streptozotocin induced diabetic (DM) rats, untreated or after blockade of NO synthesis with l-NAME. We measured arterial blood pressure (MABP), whole kidney blood flow and renal regional flows: cortical and outer- and inner-medullary (IMBF), determined as laser-Doppler fluxes.

TMAO, a seafood-derived molecule, produces diuresis and reduces mortality in heart failure rats.

Trimethylamine-oxide (TMAO) is present in seafood which is considered to be beneficial for health. Deep-water animals accumulate TMAO to protect proteins, such as lactate dehydrogenase (LDH), against hydrostatic pressure stress (HPS). We hypothesized that TMAO exerts beneficial effects on the circulatory system and protects cardiac LDH exposed to HPS produced by the contracting heart.

Clopidogrel Partially Counteracts Adenosine-5'-Diphosphate Effects on Blood Pressure and Renal Hemodynamics and Excretion in Rats.

Background: Adenosine-5'-diphosphate (ADP) can influence intrarenal vascular tone and tubular transport, partly through activation of purine P2Y12 receptors (P2Y12-R), but their actual in vivo role in regulation of renal circulation and excretion remains unclear.

Methods: The effects of intravenous ADP infusions of 2-8mg/kg/hour were examined in anesthetized Wistar rats that were untreated or chronically pretreated with clopidogrel, 20mg/kg/24hours, a selective P2Y12-R antagonist. Renal blood flow (transonic probe) and perfusion of the superficial cortex and medulla (laser-Doppler fluxes) were measured, together with urine osmolality (U), diuresis (V), total solute (UV), sodium (UV) and potassium (UV) excretion.

Renal sympathetic nerve activity after catheter-based renal denervation.

Background: Catheter-based renal sympathetic denervation (RDN) has been considered a potential treatment for therapy resistant hypertension (RHT). However, in a randomized placebo-controlled trial, RDN did not lead to a substantial blood pressure (BP) reduction. We hypothesized that variation in the reported RDN efficacy might be explained by incomplete nerve disruption as assessed by renal I-meta-iodobenzylguanidine (I-mIBG) scintigraphy.

Hypertension in rats is associated with an increased permeability of the colon to TMA, a gut bacteria metabolite.

An increased blood trimethylamine N-oxide (TMAO) has emerged as a marker of cardiovascular mortality, however, the mechanisms of the increase are not clear. We evaluated if hypertension was associated with changes in the colon permeability to trimethylamine (TMA), a TMAO precursor. We did experiments on male, 24-26-week-old normotensive Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and SHR treated with enalapril, an antihypertensive drug (SHR-E).

Epidemiology and management of hypertension in paediatric and young adult kidney transplant recipients in The Netherlands.

Introduction: Hypertension in kidney transplant recipients (KTRs) is a risk factor for cardiovascular mortality and graft loss. Data on the prevalence of hypertension and uncontrolled hypertension (uHT) in paediatric and young adult KTRs are scarce. Also, it is unknown whether 'transition' (the transfer from paediatric to adult care) influences control of hypertension.

Intracolonic hydrogen sulfide lowers blood pressure in rats.

Research suggests that hydrogen sulfide (HS) is an important biological mediator involved in various physiological processes including the regulation of arterial blood pressure (BP). Although HS is abundant in the colon, the effects of gut-derived HS on the circulatory system have not yet been investigated. We studied the effects of intracolonic administration of NaS, a HS donor, on systemic hemodynamics.

Influence of P2X receptors on renal medullary circulation is not altered by angiotensin II pretreatment.

Background: Purine P2X and P2Y receptors (P2-R) are involved in control of renal circulation, especially in the medulla, wherein they appear to interact with angiotensin II (Ang II). Our experimental approach enabled examination of interaction with Ang II per se, in the absence of blood pressure elevation. In this whole-kidney functional study we focused on the influence of P2X1-R on perfusion of the renal medulla.

Effects of Dietary Sodium Restriction in Kidney Transplant Recipients Treated With Renin-Angiotensin-Aldosterone System Blockade: A Randomized Clinical Trial.

Background: In patients with chronic kidney disease receiving renin-angiotensin-aldosterone system (RAAS) blockade, dietary sodium restriction is an often-used treatment strategy to reduce blood pressure (BP) and albuminuria. Whether these effects extend to kidney transplant recipients is unknown. We therefore studied the effects of dietary sodium restriction on BP and urinary albumin excretion (UAE) in kidney transplant recipients receiving RAAS blockade.

Effects of renal sympathetic denervation on cardiac sympathetic activity and function in patients with therapy resistant hypertension.

Background: Renal sympathetic denervation (RSD) is currently being investigated in multiple studies of sympathetically driven cardiovascular diseases such as heart failure and arrhythmias. Our aim was to assess systemic and cardiac sympatholytic effects of RSD by the measurement of cardiac sympathetic activity and cardiovascular parameters.

Methods: A total of 21 consecutive patients with refractory hypertension (daytime ambulatory blood pressure (BP)≥150/100 mmHg despite the use of 3 or more antihypertensive drugs), no evidence for secondary hypertension and normal renovascular anatomy were included.

Renal 123I-MIBG Scintigraphy Before and After Kidney Autotransplantation.

A 25-year-old man underwent an autotransplantation of his right kidney because of fibromuscular dysplasia-induced renal artery stenosis and subsequent hypertension. Since transplantation results in complete kidney denervation, it enabled assessment of renal sympathetic nerve activity changes using renal I-MIBG scintigraphy. Before and 2 weeks after transplantation I-MIBG, scintigraphy was performed.

High salt intake increases blood pressure in normal rats: putative role of 20-HETE and no evidence on changes in renal vascular reactivity.

Unlabelled: Background/Aims . High salt (HS) intake may elevate blood pressure (BP), also in animals without genetic salt sensitivity. The development of salt-dependent hypertension could be mediated by endogenous vasoactive agents; here we examined the role of vasodilator epoxyeicosatrienoic acids (EETs) and vasoconstrictor 20-hydroxyeicosatetraenoic acid (20-HETE).

Renal denervation of the native kidneys for drug-resistant hypertension after kidney transplantation.

There is a strong rationale for renal denervation (RDN) of the native kidneys in kidney transplant recipients with treatment-resistant hypertension. We present a patient with a stable graft function, who underwent RDN for posttransplant therapy-resistant hypertension (24-h ambulatory blood pressure measurement (ABPM) 143/89 mmHg, while compliantly using five different antihypertensive agents). After RDN, BP measurements and orthostatic complaints required withdrawal of two antihypertensive agents and halving a third.

Role of atrial natriuretic peptide in mediating the blood pressure-independent natriuresis elicited by systemic inhibition of nitric oxide.

While it is clearly recognized that increased intrarenal nitric oxide (NO) levels elicit natriuresis, confounding data showing that systemic nitric oxide synthase inhibition (NOSi) also increases sodium excretion (UNaV) poses a conundrum. This response has been attributed to the associated increases in arterial pressure (AP); however, the increases in AP and in UNaV are temporally dissociated. The changes in regional renal haemodynamics induced by NOSi could also contribute to the alterations of UNaV.

Treatment efficacy of hypertension in kidney transplant recipients in the Netherlands.

Background: Hypertension in kidney transplant recipients jeopardises graft and patient survival. Guidelines suggest blood pressure targets of ≤130/80 mmHg and sodium intake <90 mmol/day.

Methods: Since the efficacy of antihypertensive treatment among kidney transplant recipients is unknown, we analysed data on office-based blood pressure and use of antihypertensive drugs from the Netherlands Organ Transplant Registry on 5415 kidney transplant recipients.