The aim of the present study was to assess systemic circulatory and tissue activities of both the classical arm and of the alternative arm of the renin-angiotensin system (RAS) in a new transgenic rat line (TG7371) that expresses angiotensin-(1-7) (ANG 1-7)-producing fusion protein; the results were compared with the activities measured in control transgene-negative Hannover Sprague-Dawley (HanSD) rats. Plasma and tissue concentrations of angiotensin II (ANG II) and ANG 1-7, and kidney mRNA expressions of receptors responsible for biological actions of ANG II and ANG 1-7 [i.e. ANG II type 1 and type 2 (AT1 and AT2) and Mas receptors] were assessed in TG7371 transgene-positive and in HanSD rats. We found that male TG7371 transgene-positive rats exhibited significantly elevated plasma, kidney, heart and lung ANG 1-7 concentrations as compared with control male HanSD rats; by contrast, there was no significant difference in ANG II concentrations and no significant differences in mRNA expression of AT1, AT2 and Mas receptors. In addition, we found that in male TG7371 transgene-positive rats blood pressure was lower than in male HanSD rats. These data indicate that the balance between the classical arm and the alternative arm of the RAS was in male TGR7371 transgene-positive rats markedly shifted in favor of the latter. In conclusion, TG7371 transgene-positive rats represent a new powerful tool to study the long-term role of the alternative arm of the RAS in the pathophysiology and potentially in the treatment of cardio-renal diseases.
- MeSH
- angiotensin I * metabolismus MeSH
- angiotensin II * MeSH
- kardiovaskulární nemoci metabolismus genetika MeSH
- krevní tlak fyziologie MeSH
- krysa rodu rattus MeSH
- ledviny metabolismus MeSH
- nemoci ledvin metabolismus genetika MeSH
- peptidové fragmenty * metabolismus MeSH
- potkani Sprague-Dawley * MeSH
- potkani transgenní * MeSH
- protoonkogen Mas MeSH
- receptor angiotensinu typ 1 genetika metabolismus MeSH
- receptory spřažené s G-proteiny genetika metabolismus MeSH
- rekombinantní fúzní proteiny metabolismus MeSH
- renin-angiotensin systém * fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Sympathetic hyperactivity and relative NO deficiency are characteristic alterations in both genetic and salt hypertension. The contribution of these abnormalities to blood pressure (BP) maintenance can be determined in conscious rats using a consecutive blockade of particular vasoactive systems. Thus, the contribution of pressor effects of angiotensin II to the maintenance of high BP is usually small, but the role of renin-angiotensin system in the development of hypertension mediated by central and peripheral effects of angiotensin II on sympathetic activity is highly important. This is even true in angiotensin-dependent hypertension of heterozygous Ren-2 transgenic rats in which sympathetic hyperactivity is increasing with age. Central sympathoexcitation in this hypertensive model can be inhibited by lower losartan doses than peripheral angiotensin II-dependent vasoconstriction. This experimental model also yielded important knowledge on nephroprotective effects of new therapeutic drugs - endothelin receptor type A blockers. A considerable part of sympathetic vasoconstriction is dependent on the interaction of Ca2+ sensitization (RhoA/Rho kinase pathway) and Ca2+ influx (through L-VDCC). The blockade of these pathways prevents a major part of sympathetic vasoconstriction. Ca2+ sensitization seems to be attenuated in genetic hypertension in order to compensate increased Ca2+ influx. In contrast, enhanced Ca2+ sensitization is a hallmark of salt sensitivity in Dahl rats in which salt hypertension is dependent on increased Ca2+ influx. The attention should also be paid to the impairment of arterial baroreflex sensitivity which permits enhanced BP responses to pressor or depressor stimuli. Some abnormalities can be studied in blood vessels isolated from hypertensive rats but neither conduit arteries nor mesenteric resistance arteries represent the vascular beds decisive for the increased peripheral resistance and high BP. Keywords: Sympathetic vasoconstriction, NO-dependent vasodilatation, Calcium sensitization, Calcium influx, Arterial baroreflex, Spontaneously hypertensive rats, Salt hypertensive Dahl rats, Ren-2 transgenic rats, RAS blockade, SNS blockade, NOS inhibition, Endothelin, Vascular contraction and relaxation, Isolated conduit and resistance arteries, EDCF, PGI2, BKCa channels.
- MeSH
- hypertenze * patofyziologie metabolismus MeSH
- krevní tlak účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- renin-angiotensin systém účinky léků fyziologie MeSH
- sympatický nervový systém patofyziologie účinky léků MeSH
- vazodilatace účinky léků fyziologie MeSH
- vazokonstrikce * účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- MeSH
- aldosteron fyziologie nedostatek MeSH
- lidé MeSH
- renin-angiotensin systém fyziologie účinky léků MeSH
- Check Tag
- lidé MeSH
Although the administration of crystalloid fluids is one of the most frequently used treatment procedures, we often forget that the administration of fluids should be governed by the same rules that apply to the administration of any medicinal product. Fluid administration has its indications and contraindications, the exact dose should be defined and both therapeutic effects and goals, as well as possible adverse effects accompanying fluid administration, should be monitored. Each time a crystalloid fluid is administered, we must think about its composition in the context of the patient's clinical condition, and from this point of view, we should individualize the treatment. The aim of this article is to describe the physiology and pathophysiology of fluids, to clarify the historical context of the development of the composition of crystalloid fluids used in clinical practice, and to provide an up-to-date view of the therapeutic parenteral administration of crystalloid fluids in children from infancy to 18 years of age. The information in the article does not relate to the neonatal age and does not address the enteral form of rehydration.
- MeSH
- dehydratace terapie MeSH
- dítě MeSH
- krystaloidní roztoky MeSH
- lidé MeSH
- rehydratační roztoky MeSH
- renin-angiotensin systém MeSH
- tekutinová terapie * metody MeSH
- vasopresiny MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
BACKGROUND: Hyperkalemia (HK) is associated with suboptimal renin-angiotensin system (RAS) inhibitor and mineralocorticoid receptor antagonist (MRA) use in heart failure with reduced ejection fraction (HFrEF). OBJECTIVES: This study sought to assess characteristics and RAS inhibitor/MRA use in patients receiving patiromer during the DIAMOND (Patiromer for the Management of Hyperkalemia in Subjects Receiving RAASi Medications for the Treatment of Heart Failure) run-in phase. METHODS: Patients with HFrEF and HK or past HK entered a run-in phase of ≤12 weeks with patiromer-facilitated RAS inhibitor/MRA optimization to achieve ≥50% recommended RAS inhibitor dose, 50 mg/d MRA, and normokalemia. Patients achieving these criteria (randomized group) were compared with the run-in failure group (patients not meeting the randomization criteria). RESULTS: Of 1,038 patients completing the run-in, 878 (84.6%) were randomized and 160 (15.4%) were run-in failures. Overall, 422 (40.7%) had HK entering run-in with a similar frequency in the randomized and run-in failure groups (40.3% vs 42.5%; P = 0.605). From start to the end of run-in, in the randomized group, an increase was observed in target RAS inhibitor and MRA use in patients with HK (RAS inhibitor: 76.8% to 98.6%; MRA: 35.9% to 98.6%) and past HK (RAS inhibitor: 60.5% to 98.1%; MRA: 15.6% to 98.7%). Despite not meeting the randomization criteria, an increase after run-in was observed in the run-in failure group in target RAS inhibitor (52.5% to 70.6%) and MRA use (15.0% to 48.1%). This increase was observed in patients with HK (RAS inhibitor: 51.5% to 64.7%; MRA: 19.1% to 39.7%) and past HK (RAS inhibitor: 53.3% to 75.0%; MRA: 12.0% to 54.3%). CONCLUSIONS: In patients with HFrEF and HK or past HK receiving suboptimal RAS inhibitor/MRA therapy, RAS inhibitor/MRA optimization increased during patiromer-facilitated run-in.
- MeSH
- antagonisté mineralokortikoidních receptorů * terapeutické užití MeSH
- antagonisté receptorů pro angiotenzin terapeutické užití MeSH
- hyperkalemie * farmakoterapie krev MeSH
- inhibitory ACE terapeutické užití MeSH
- lidé středního věku MeSH
- lidé MeSH
- polymery * terapeutické užití MeSH
- renin-angiotensin systém účinky léků MeSH
- senioři MeSH
- srdeční selhání * farmakoterapie MeSH
- tepový objem účinky léků MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- randomizované kontrolované studie MeSH
The study of ontogenetic aspects of water and electrolyte metabolism performed in the Institute of Physiology (Czechoslovak Academy of Sciences) led to the research on the increased susceptibility of immature rats to salt-dependent forms of hypertension since 1966. Hemodynamic studies in developing rats paved the way to the evaluation of hemodynamic mechanisms during the development of genetic hypertension in SHR. A particular attention was focused on altered renal function and kidney damage in both salt and genetic hypertension with a special respect to renin-angiotensin system. Renal damage associated with hypertension progression was in the center of interest of several research groups in Prague. The alterations in ion transport, cell calcium handling and membrane structure as well as their relationship to abnormal lipid metabolism were studied in a close cooperation with laboratories in Munich, Glasgow, Montreal and Paris. The role of NO and oxidative stress in various forms of hypertension was a subject of a joint research with our Slovak colleagues focused mainly on NO-deficient hypertension elicited by chronic L-NAME administration. Finally, we adopted a method enabling us to evaluate the balance of vasoconstrictor and vasodilator mechanisms in BP maintenance. Using this method we demonstrated sympathetic hyperactivity and relative NO deficiency in rats with either salt-dependent or genetic hypertension. At the end of the first decennium of this century we were ready to modify our traditional approach towards modern trends in the research of experimental hypertension. Keywords: Salt-dependent hypertension o Genetic hypertension o Body fluids o Hemodynamics o Ion transport o Cell membrane structure and function o Renal function o Renin-angiotensin systems.
- MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- hypertenze * metabolismus patofyziologie MeSH
- krevní tlak MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- renin-angiotensin systém MeSH
- zvířata MeSH
- Check Tag
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
x
x
- Klíčová slova
- finerenon, Esaxerenon, Firibastat(OGC001), Bosentan, Darusentan, Aprocitentan, studie FIDELIO -DKD, studie FIGARO-DKD, studie FIDELITY, studie FRESH, studie PRECISION,
- MeSH
- antagonisté mineralokortikoidních receptorů farmakologie MeSH
- antihypertenziva * farmakologie klasifikace MeSH
- endoteliny fyziologie MeSH
- glutamylaminopeptidasa fyziologie MeSH
- klinické zkoušky, fáze II jako téma MeSH
- klinické zkoušky, fáze III jako téma MeSH
- lidé MeSH
- natriuretické peptidy fyziologie MeSH
- renin-angiotensin systém účinky léků MeSH
- vyvíjení léků * trendy MeSH
- Check Tag
- lidé MeSH
This study investigated whether sacubitril/valsartan or valsartan are able to prevent left ventricular (LV) fibrotic remodelling and dysfunction in two experimental models of pre-hypertension induced by continuous light (24 hours/day) exposure or by chronic lactacystin treatment, and how this potential protection interferes with the renin-angiotensin-aldosterone system (RAAS). Nine groups of three-month-old male Wistar rats were treated for six weeks as follows: untreated controls (C), sacubitril/valsartan (ARNI), valsartan (Val), continuous light (24), continuous light plus sacubitril/valsartan (24+ARNI) or valsartan (24+Val), lactacystin (Lact), lactacystin plus sacubitil/valsartan (Lact+ARNI) or plus valsartan (Lact+Val). Both the 24 and Lact groups developed a mild but significant systolic blood pressure (SBP) increase, LV hypertrophy and fibrosis, as well as LV systolic and diastolic dysfunction. Yet, no changes in serum renin-angiotensin were observed either in the 24 or Lact groups, though aldosterone was increased in the Lact group compared to the controls. In both models, sacubitril/valsartan and valsartan reduced elevated SBP, LV hypertrophy and fibrosis and attenuated LV systolic and diastolic dysfunction. Sacubitril/valsartan and valsartan increased the serum levels of angiotensin (Ang) II, Ang III, Ang IV, Ang 1-5, Ang 1-7 in the 24 and Lact groups and reduced aldosterone in the Lact group. We conclude that both continuous light exposure and lactacystin treatment induced normal-to-low serum renin-angiotensin models of pre-hypertension, whereas aldosterone was increased in lactacystin-induced pre-hypertension. The protection by ARNI or valsartan in the hypertensive heart in either model was related to the Ang II blockade and the protective Ang 1-7, while in lactacystin-induced pre-hypertension this protection seems to be additionally related to the reduced aldosterone level.
- MeSH
- acetylcystein analogy a deriváty MeSH
- aldosteron MeSH
- aminobutyráty * MeSH
- bifenylové sloučeniny farmakologie MeSH
- fibróza MeSH
- fixní kombinace léků MeSH
- hypertenze * farmakoterapie MeSH
- hypertrofie levé komory srdeční MeSH
- krysa rodu rattus MeSH
- potkani Wistar MeSH
- prehypertenze * MeSH
- renin-angiotensin systém MeSH
- renin MeSH
- srdeční selhání * MeSH
- tepový objem MeSH
- tetrazoly farmakologie terapeutické užití MeSH
- valsartan farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Angiotensin-converting enzyme 2 (ACE2), one of the key enzymes of the renin-angiotensin system (RAS), plays an important role in SARS-CoV-2 infection by functioning as a virus receptor. Angiotensin peptides Ang I and Ang II, the substrates of ACE2, can modulate the binding of SARS-CoV-2 Spike protein to the ACE2 receptor. In the present work, we found that co incubation of HEK-ACE2 and Vero E6 cells with the SARS-CoV-2 Spike pseudovirus (PVP) resulted in stimulation of the virus entry at low and high micromolar concentrations of Ang I and Ang II, respectively. The potency of Ang I and Ang II stimulation of virus entry corresponds to their binding affinity to ACE2 catalytic pocket with 10 times higher efficiency of Ang II. The Ang II induced mild increase of PVP infectivity at 20 microM; while at 100 microM the increase (129.74+/-3.99 %) was highly significant (p<0.001). Since the angiotensin peptides act in HEK ACE2 cells without the involvement of angiotensin type I receptors, we hypothesize that there is a steric interaction between the catalytic pocket of the ACE2 enzyme and the SARS-CoV-2 S1 binding domain. Oversaturation of the ACE2 with their angiotensin substrate might result in increased binding and entry of the SARS-CoV-2. In addition, the analysis of angiotensin peptides metabolism showed decreased ACE2 and increased ACE activity upon SARS-CoV-2 action. These effects should be taken into consideration in COVID-19 patients suffering from comorbidities such as the over-activated renin-angiotensin system as a mechanism potentially influencing the SARS-CoV-2 invasion into recipient cells.
- MeSH
- angiotensin I metabolismus farmakologie MeSH
- angiotensin II metabolismus MeSH
- angiotensin konvertující enzym metabolismus MeSH
- angiotensin-konvertující enzym 2 metabolismus MeSH
- COVID-19 * MeSH
- glykoprotein S, koronavirus * MeSH
- inhibitory ACE MeSH
- lidé MeSH
- renin-angiotensin systém * MeSH
- SARS-CoV-2 metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
