Previous investigations revealed that most of the fluid regulating hormones showed no consistent relationship to the hypoxic diuretic response (HDR). In this study we examined if adrenomedullin (AM), a hypoxia-mediated diuretic/natriuretic peptide is connected to HDR. Thirty-three persons were examined at low altitude (LA), on the third exposure day at 3440 m (medium altitude, MA) and on the fourteenth day at 5050 m (high altitude, HA). Nocturnal diuresis rose from 460 ml [interquartile range 302 ml] at LA to 560 [660] ml at MA to 1015 [750] ml at HA (p<0.005). Sodium excretion was similar at LA and MA (41.8 [27.0] vs. 41.4 [28.4] mM) and increased to 80.2 [29.1] mM at HA (p<0.005). Urinary AM excretion was 7.9 [3.9] at LA, 7.5 [5.7] pM at MA, and increased to 10.5 [5.1] pM (p<0.05) at HA. Urinary AM excretion was correlated to diuresis (r=0.72, p<0.005) and sodium excretion (r=0.57, p<0.005). Plasma AM concentration rose from 16.4 [3.1] to 18.8 [4.9] pM/l at MA (p<0.005) and to 18.3 [4.3] pM/l at HA (p<0.005). Plasma AM concentration and urinary AM excretion were not correlated, neither were plasma AM concentration and diuresis or natriuresis. Our data suggest the involvement of increased renal AM production in the pathophysiology of high altitude fluid and sodium loss., B. Haditsch, A. Roessler, H. G. Hinghofer-Szalkay., and Obsahuje bibliografii a bibliografické odkazy
The relationship between obesity and renal lesions, especially in low estrogen levels, has been less documented. The aim of this study was to assess the renal changes in diet-induced obesity in ovariectomized rats. Wistar rats were ovariectomized or shamoperated and divided into four groups: sham-operated rats fed a standard diet (SSD); ovariectomized rats fed a standard diet (OSD); sham-operated rats fed a high-fat diet (SHFD); ovariectomized rats fed a high-fat diet (OHFD). Body weight and blood pressure were measured weekly. The rats were killed 24 weeks after initiation of standard or high-fat diet treatment, the kidneys were removed for immunohistochemical and histological studies. Blood and urine samples were collected to quantify sodium, potassium and creatinine. OHFD rats presented increases in visceral adipose tissue, serum insulin levels, blood pressure and proteinuria, and a decrease in fractional excretion of sodium as well. Histological and morphometric studies showed focal alterations in the renal cortex. Expression of macrophages, lymphocytes, nuclear factor-kappa B (NF-B), Proliferating Cell Nuclear Antigen (PCNA), angiotensin II (ANG II) and vimentin was greater in OHFD rats than in control rats. Thus, these results demonstrate that the high-fat diet in ovariectomized rats promoted renal function and structure changes, renal interstitial infiltration of mononuclear cells and increased expression of ANG II and NF-κB., L. S: B. Amaral, J. A. Silva, T. M. Trindade, W. B. D. Ribas, C. L. Macedo, T. M. Coimbra, N. O. Belo, A. C. M. Magalhães, T. J. Soares., and Obsahuje bibliografii
The influence of renal nerves on the effects of concurrent NO synthase inhibition (10 mg kg-1 b.w. i.v. L-NAME) and ETA/ETB receptor inhibition (10 mg kg-1 b.w. i.v. bosentan) on renal excretory function and blood pressure in conscious spontaneously hypertensive rats (SHR) was investigated. L-NAME increased blood pressure, urine flow rate, fractional excretion of sodium, chloride and phosphate in both normotensive Wistar rats and SHR with intact renal nerves (p<0.01). GFR or RBF did not change in any of the groups investigated. The effects of L-NAME on renal excretory function were markedly reduced by bosentan and the values returned to control level in the normotensive rats, while in SHR the values were reduced by bosentan, but they remained significantly elevated as compared to control level (p<0.05). The hypertensive response induced by L-NAME in SHR is partially due to activation of endogenous endothelins, but it does not depend on renal nerves. Chronic bilateral renal denervation abolished the effect of L-NAME on sodium and chloride excretion in normotensive rats, whereas it did not alter this effect in SHR. The participation of endogenous endothelins in changes of renal excretory function following NO synthase inhibition is diminished in SHR as compared to Wistar rats., R. Girchev, P. Markova., and Obsahuje bibliografii a bibliografické odkazy
Varied causative and risk factors can lead to cardiac dysfunction. Cardiac dysfunction often evolves into heart failure by cardiac remodeling due to autonomic nervous system disturbance and neurohumoral abnormalities, even if the detriment factors are removed. Renal sympathetic nerve activity plays a pivotal regulatory role in neurohumoral mechanisms. The present study was designed to determine the therapeutic eff ects of renal sympathetic denervation (RSD) on cardiac dysfunction, fibrosis, and neurohumoral response in transverse aortic constriction (TAC) rats with chronic pressure overload. The present study demonstrated that RSD attenuated myocardial fibrosis and hypertrophy, and structural remodeling of the left atrium and ventricle, up -regulated cardiac β adrenoceptor (β -AR, including β 1 AR and β 2 AR) and sarco -endoplasmic reticulum Ca 2+ -ATP ase (SERCA) while down -regulated angiotensin II type 1 receptor (AT 1 R), and decreased plasma B -type natriuretic peptide (BNP), norepinephrine (NE) , angiotensin II (Ang II), and arginine vasopressin (AVP) levels in TAC rats with chronic pressure overload. We conclude that RSD attenuates myocardial fibrosis, the left atrial enlargement, and the left ventricular wall hypertrophy; inhibits the overdrive of the sympathetic ner vous system (SNS), renin- angiotensin -aldosterone system (RAAS), and AVP system in TAC rats with chronic pressure overload . RSD could be a promising non -pharmacological approach to control the progression of cardiac dysfunction., Z.-Z. Li, H. Jiang, D. Chen, Q. Liu, J. Geng, J.-Q. Guo, R.-H. Sun, G.-Q. Zhu, Q.-J. Shan., and Obsahuje bibliografii
Renální denervace je novou metodou v terapii farmakorezistentní hypertenze, která spočívá v selektivním přerušení sympatických vláken v adventicii renálních tepen. Dosud nebyly publikovány výsledky randomizovaných zaslepených studií, které by prokázaly efektivitu tohoto zákroku. Budoucnost ukáže, jestli bude metoda široce indikována v léčbě hypertenze či jiných chorob, které souvisejí se zvýšenou aktivitou sympatiku, nebo najde uplatnění pouze u selektovaných skupin pacientů nebo se stane slepou cestou lidského poznání., Renal denervation is a novel method in the treatment of resistant hypertension, which is based on selective ablation of sympathetic nervous fibres in the adventitia of renal arteries. The results of randomized, double‑blind trials which would prove efficacy of this method have not been published yet. We will find out in the near future whether this method will be widely indicated for the treatment of hypertension and other diseases associated with increased sympathetic activity, whether renal denervation will be applied only to selected groups of patients, or whether it is a wrong way on the road of human knowledge., and Mikušová T., Stárek Z., Jež J., Lehar F., Špinarová L.
Je jen mále oblastí ve vnitřním lékařství, které zaznamenaly extrémně rychlý rozmach a implementaci do klinické praxe v posledních 5 letech, jako je katetrizační renální denervace (RDN) u pacientů nejen s rezistentní hypertenzí. Základním problémem, který nebyl dostatečně řešen ve všech studiích s RDN, je skutečnost, že více než 50 % pacientů s tzv. rezistentní hypertenzí jsou ve skutečnosti nemocní neukáznění a neadherující k zavedené mediaci. Výsledky studie SYMPLICITY HTN-3 neprokázaly žádné rozdíly mezi změnou krevního tlaku u pacientů s provedenou RDN proti skupině s tzv. falešnou procedurou, tedy pokračující medikamentózní terapií. Budoucnost RDN je více než otazná a je potřeba vrátit se zpět k animálním studiím, které ověří reálnou efektivitu RDN redefinovat populaci pacientů indikovaných k RDN a ověřit použitelnost nově vyvinutých technologií., Transcatheter renal denervation (RDN) has been markedly applied and developed in clinical practice in past five years and not only for patients with resistant hypertension. The issue that more than 50% patients with so-called resistant hypertension are in fact patients without adherence to this type of mediation has not been resolved in RDN trials till now. The study Symplicity HTN-3 showed no differences in blood pressure change between the patients with RDN and group of patients after false procedure who continued in their drug therapy. Future of RDN is more than questionable and there is a need to return to animal studies that will verify the real effectiveness of RDN, subsequently, will redefine population of patients indicated for RDN and confirm the applicability of newly developed techniques., and Miloš Táborský, Marcela Schejbalová