OBJECTIVES: Due to poor treatment adherence and lifestyle-based interventions, chronic hypertension is a dominant risk factor predisposing individuals to heart failure and malignant arrhythmias. We investigated the impact of the postnatal acclimation of hairless SHR to ambient temperature that is, for them, below thermoneutrality, on the electrical coupling protein connexin-43 (Cx43) and pro-fibrotic markers in both heart ventricles of male and female hairless SHR rats compared to the wild SHR. METHODS: Some 6-month-acclimated male and female hairless SHR as well as age- and sex-matched wild SHR were included and compared with the non-hypertensive Wistar strain. The left and right heart ventricles were examined for Cx43 topology, myocardial structure, and the histochemistry of capillaries. The protein levels of Cx43, relevant protein kinases, and extracellular matrix proteins (ECMs) were determined by immunoblotting. MMP-2 activity was assessed via zymography, and susceptibility to malignant arrhythmias was tested ex vivo. RESULTS: Cx43 and its phosphorylated variant pCx43368 were significantly reduced in the left heart ventricles of wild SHR males, while to a lesser extent in the hairless SHR. In contrast, these proteins were not significantly altered in the right heart ventricles of males or in both heart ventricles in females, regardless of the rat strain. Pro-arrhythmic Cx43 topology was detected in the left heart ventricle of wild SHR and to a lesser extent in hairless SHR males. TGFβ protein was significantly increased only in the left ventricle of the wild SHR males. MMP-2 activity was increased in the right ventricle but not in the left ventricles of both males and females, regardless of the rat strain. CONCLUSIONS: The findings indicate that the postnatal acclimation of hairless SHR to ambient temperature hampers the downregulation of Cx43 in the left heart ventricle compared to wild SHR males. The decline of Cx43 was much less pronounced in females and not observed in the right heart ventricles, regardless of the rat strain. It may impact the susceptibility of the heart to malignant arrhythmias.

• MeSH
• aklimatizace MeSH
• down regulace MeSH
• hypertenze * metabolismus   MeSH
• konexin 43 * metabolismus   genetika   MeSH
• krysa rodu rattus MeSH
• potkani inbrední SHR * MeSH
• potkani Wistar MeSH
• srdeční arytmie * metabolismus   etiologie   MeSH
• srdeční komory * metabolismus   MeSH
• teplota * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Recently, we have identified a recessive mutation, an abnormal coat appearance in the BXH6 strain, a member of the HXB/BXH set of recombinant inbred (RI) strains. The RI strains were derived from the spontaneously hypertensive rat (SHR) and Brown Norway rat (BN-Lx) progenitors. Whole genome sequencing of the mutant rats identified the 195875980 G/A mutation in the tuftelin 1 (Tuft1) gene on chromosome 2, which resulted in a premature stop codon. Compared with wild-type BXH6 rats, BXH6-Tuft1 mutant rats exhibited lower body weight due to reduced visceral fat and ectopic fat accumulation in the liver and heart. Reduced adiposity was associated with decreased serum glucose and insulin and increased insulin-stimulated glycogenesis in skeletal muscle. In addition, mutant rats had lower serum monocyte chemoattractant protein-1 and leptin levels, indicative of reduced inflammation. Analysis of the liver proteome identified differentially expressed proteins from fatty acid metabolism and β-oxidation, peroxisomes, carbohydrate metabolism, inflammation, and proteasome pathways. These results provide evidence for the important role of the Tuft1 gene in the regulation of lipid and glucose metabolism and suggest underlying molecular mechanisms.NEW & NOTEWORTHY A new spontaneous mutation, abnormal hair appearance in the rat, has been identified as a nonfunctional tuftelin 1 (Tuft1) gene. The pleiotropic effects of this mutation regulate glucose and lipid metabolism. Analysis of the liver proteome revealed possible molecular mechanisms for the metabolic effects of the Tuft1 gene.

• MeSH
• glukosa * metabolismus   MeSH
• inzulin metabolismus   MeSH
• krysa rodu rattus MeSH
• metabolismus lipidů genetika   MeSH
• nesmyslný kodon * genetika   MeSH
• potkani inbrední BN MeSH
• potkani inbrední SHR MeSH
• proteom metabolismus   MeSH
• zánět MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Substituted catechols include both natural and synthetic compounds found in the environment and foods. Some of them are flavonoid metabolites formed by the gut microbiota which are absorbed afterwards. Our previous findings showed that one of these metabolites, 4-methylcatechol, exerts potent vasorelaxant effects in rats. In the current study, we aimed at testing of its 22 structural congeners in order to find the most potent structure and to investigate the mechanism of action. 3-methoxycatechol (3-MOC), 4-ethylcatechol, 3,5-dichlorocatechol, 4-tert-butylcatechol, 4,5-dichlorocatechol, 3-fluorocatechol, 3-isopropylcatechol, 3-methylcatechol and the parent 4-methylcatechol exhibited high vasodilatory activities on isolated rat aortic rings with EC50s ranging from ∼10 to 24 μM. Some significant sex-differences were found. The most potent compound, 3-MOC, relaxed also resistant mesenteric artery but not porcine coronary artery, and decreased arterial blood pressure in both male and female spontaneously hypertensive rats in vivo without affecting heart rate. It potentiated the vasodilation mediated by cAMP and cGMP, but did not impact L-type Ca2+-channels. By using two inhibitors, activation of voltage-gated potassium channels (KV) was found to be involved in the mechanism of action. This was corroborated by docking analysis of 3-MOC with the KV7.4 channel. None of the most active catechols decreased the viability of the A-10 rat embryonic thoracic aorta smooth muscle cell line. Our findings showed that various catechols can relax vascular smooth muscles and hence could provide templates for developing new antihypertensive vasodilator agents without affecting coronary circulation.

• MeSH
• aorta thoracica účinky léků   metabolismus   MeSH
• arteriae mesentericae * účinky léků   metabolismus   MeSH
• arteriální tlak účinky léků   MeSH
• draslíkové kanály řízené napětím metabolismus   antagonisté a inhibitory   účinky léků   MeSH
• guanosinmonofosfát cyklický metabolismus   MeSH
• hypertenze farmakoterapie   patofyziologie   metabolismus   MeSH
• katecholy * farmakologie   chemie   MeSH
• koronární cévy účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• modely nemocí na zvířatech MeSH
• myocyty hladké svaloviny účinky léků   metabolismus   MeSH
• potkani inbrední SHR * MeSH
• prasata MeSH
• sexuální faktory MeSH
• simulace molekulového dockingu * MeSH
• svaly hladké cévní účinky léků   metabolismus   MeSH
• vazodilatace * účinky léků   MeSH
• vazodilatancia * farmakologie   chemie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Koletsky rats, the genetically obese strain of spontaneously hypertensive rats (SHROB), are the well-accepted animal model of human metabolic syndrome. They are characterized by early onset obesity, spontaneous hypertension, hyperinsulinemia, hyperlipidemia, proteinuria and shortened life-span. One of the factors in the pathogenesis of metabolic syndrome is oxidative stress. The aim of the present study was to compare two parameters related to oxidative stress: the levels of the main intracellular antioxidant, reduced glutathione as well as the indirect indicator of lipid peroxidation damage, thiobarbituric acid-reactive substances (TBARS) in heart, renal cortex and medulla and liver in male lean spontaneously hypertensive rats (SHR) and obese Koletsky rats. We did not find any significant differences in these markers in heart and kidneys. However, we found significantly lower glutathione level in Koletsky rat liver compared with SHR (5.03+/-0.23 vs. 5.83+/-0.14 μmol/g tissue, respectively). On the contrary, we observed significantly higher TBARS levels in Koletsky rat liver compared with SHR (28.56+/-2.15 vs. 21.83+/-1.60 nmol/mg protein, respectively). We conclude that the liver is the most sensitive tissue to oxidative damage with the significantly decreased concentration of glutathione and the significantly increased concentration of TBARS in obese Koletsky rats in comparison with lean control SHR.

• MeSH
• glutathion * metabolismus   MeSH
• hypertenze metabolismus   MeSH
• játra * metabolismus   MeSH
• krysa rodu rattus MeSH
• látky reagující s kyselinou thiobarbiturovou metabolismus   MeSH
• ledviny metabolismus   MeSH
• myokard metabolismus   MeSH
• obezita * metabolismus   MeSH
• oxidační stres * fyziologie   MeSH
• peroxidace lipidů * MeSH
• potkani inbrední SHR * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

We hypothesized that sympathetic hyperactivity and parasympathetic insuficiency in spontaneously hypertensive rats (SHR) underlie their exaggerated cardiovascular response to acute stress and impaired adaptation to repeated restraint stress exposure compared to Wistar-Kyoto rats (WKY). Cardiovascular responses to single (120 min) or repeated (daily 120 min for 1 week) restraint were measured by radiotelemetry and autonomic balance was evaluated by power spectral analysis of systolic blood pressure variability (SBPV) and heart rate variability (HRV). Baroreflex sensitivity (BRS) was measured by the pharmacological Oxford technique. Stress-induced pressor response and vascular sympathetic activity (low-frequency component of SBPV) were enhanced in SHR subjected to single restraint compared to WKY, whereas stress-induced tachycardia was similar in both strains. SHR exhibited attenuated cardiac parasympathetic activity (high-frequency component of HRV) and blunted BRS compared to WKY. Repeated restraint did not affect the stress-induced increase in blood pressure. However, cardiovascular response during the post-stress recovery period of the 7th restraint was reduced in both strains. The repeatedly restrained SHR showed lower basal heart rate during the dark (active) phase and slightly decreased basal blood pressure during the light phase compared to stress-naive SHR. SHR subjected to repeated restraint also exhibited attenuated stress-induced tachycardia, augmented cardiac parasympathetic activity, attenuated vascular sympathetic activity and improved BRS during the last seventh restraint compared to single-stressed SHR. Thus, SHR exhibited enhanced cardiovascular and sympathetic responsiveness to novel stressor exposure (single restraint) compared to WKY. Unexpectedly, the adaptation of cardiovascular and autonomic responses to repeated restraint was more effective in SHR.

• MeSH
• autonomní nervový systém * patofyziologie   MeSH
• baroreflex * fyziologie   MeSH
• fyzické omezení * MeSH
• fyziologická adaptace * fyziologie   MeSH
• hypertenze * patofyziologie   MeSH
• krevní tlak * fyziologie   MeSH
• krysa rodu rattus MeSH
• potkani inbrední SHR * MeSH
• potkani inbrední WKY * MeSH
• psychický stres patofyziologie   MeSH
• srdeční frekvence * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Spontaneously hypertensive rats (SHR) are characterized by sympathetic hyperactivity and insufficient parasympathetic activity, and their high blood pressure (BP) can be lowered by long-term inhibition of the renin-angiotensin system. The aim of our study was to determine the influence of chronic inhibition of angiotensin converting enzyme (ACE) by captopril on cardiovascular regulation by the sympathetic and parasympathetic nervous system. Implanted radiotelemetric probes or arterial cannulas were used to measure mean arterial pressure (MAP), heart rate (HR), and arterial baroreflex in adult SHR and Wistar-Kyoto (WKY) rats under basal or stress conditions. MAP and the low-frequency component of systolic blood pressure variability (LF-SBPV, marker of sympathetic activity) were greater in SHR than in WKY rats. Under basal conditions chronic captopril treatment reduced both parameters more effectively in SHR, and the same was true during acute restraint stress. HR was similar in control rats of both strains, but WKY rats showed greater heart rate variability (HRV), indicating higher parasympathetic activity. Captopril administration increased HR in both strains, whereas HRV was decreased only in WKY. Chronic captopril treatment improved the impaired baroreflex-HR control in SHR by increasing the sensitivity but not the capacity of vagal arm of arterial baroreflex. Captopril treatment attenuated BP changes elicited by dimethylphenylpiperazinium (DMPP, agonist of nicotinic acetylcholine receptors), especially in SHR, indicating that sympathetic nerve transmission is facilitated by angiotensin II more in hypertensive than in normotensive animals. Thus, chronic ACE inhibition improves baroreflex sensitivity and lowers BP through both central and peripheral attenuation of sympathetic tone.

• MeSH
• baroreflex * účinky léků   MeSH
• hypertenze farmakoterapie   patofyziologie   enzymologie   MeSH
• inhibitory ACE * farmakologie   MeSH
• kaptopril * farmakologie   MeSH
• krevní tlak * účinky léků   MeSH
• krysa rodu rattus MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• srdeční frekvence * účinky léků   MeSH
• sympatický nervový systém * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: C-reactive protein (CRP) is an acute inflammatory protein detected in obese patients with metabolic syndrome. Moreover, increased CRP levels have been linked with atherosclerotic disease, congestive heart failure, and ischemic heart disease, suggesting that it is not only a biomarker but also plays an active role in the pathophysiology of cardiovascular diseases. Since endothelial dysfunction plays an essential role in various cardiovascular pathologies and is characterized by increased expression of cell adhesion molecules and inflammatory markers, we aimed to detect specific markers of endothelial dysfunction, inflammation, and oxidative stress in spontaneously hypertensive rats (SHR) expressing human CRP. This model is genetically predisposed to the development of the metabolic syndrome. METHODS: Transgenic SHR male rats (SHR-CRP) and non-transgenic SHR (SHR) at the age of 8 months were used. Metabolic profile (including serum and tissue triglyceride (TAG), serum insulin concentrations, insulin-stimulated incorporation of glucose, and serum non-esterified fatty acids (NEFA) levels) was measured. In addition, human serum CRP, MCP-1 (monocyte chemoattractant protein-1), and adiponectin were evaluated by means of ELISA, histological analysis was used to study morphological changes in the aorta, and western blot analysis of aortic tissue was performed to detect expression of endothelial, inflammatory, and oxidative stress markers. RESULTS: The presence of human CRP was associated with significantly decreased insulin-stimulated glycogenesis in skeletal muscle, increased muscle and hepatic accumulation of TAG and decreased plasmatic cGMP concentrations, reduced adiponectin levels, and increased monocyte chemoattractant protein-1 (MCP-1) levels in the blood, suggesting pro-inflammatory and presence of multiple features of metabolic syndrome in SHR-CRP animals. Histological analysis of aortic sections did not reveal any visible morphological changes in animals from both SHR and SHR-CRP rats. Western blot analysis of the expression of proteins related to the proper function of endothelium demonstrated significant differences in the expression of p-eNOS/eNOS in the aorta, although endoglin (ENG) protein expression remained unaffected. In addition, the presence of human CRP in SHR in this study did not affect the expression of inflammatory markers, namely p-NFkB, P-selectin, and COX2 in the aorta. On the other hand, biomarkers related to oxidative stress, such as HO-1 and SOD3, were significantly changed, indicating the induction of oxidative stress. CONCLUSIONS: Our findings demonstrate that CRP alone cannot fully induce the expression of endothelial dysfunction biomarkers, suggesting other risk factors of cardiovascular disorders are necessary to be involved to induce endothelial dysfunction with CRP.

• MeSH
• adiponektin MeSH
• aorta MeSH
• biologické markery metabolismus   MeSH
• C-reaktivní protein metabolismus   MeSH
• chemokin CCL2 MeSH
• hypertenze * MeSH
• inzuliny * metabolismus   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• metabolický syndrom * diagnóza   genetika   MeSH
• oxidační stres MeSH
• potkani inbrední SHR MeSH
• zánět MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

A combination of liver and heart dysfunction worsens the prognosis of human survival. The aim of this study was to investigate whether empagliflozin (a sodium-glucose transporter-2 inhibitor) has beneficial effects not only on cardiac and renal function but also on hepatic function. Adult (6-month-old) male spontaneously hypertensive rats (SHR) were fed a high-fat diet (60% fat) for four months to induce hepatic steatosis and mild heart failure. For the last two months, the rats were treated with empagliflozin (empa, 10 mg.kg-1.day-1 in the drinking water). Renal function and oral glucose tolerance test were analyzed in control (n=8), high-fat diet (SHR+HF, n=10), and empagliflozin-treated (SHR+HF+empa, n=9) SHR throughout the study. Metabolic parameters and echocardiography were evaluated at the end of the experiment. High-fat diet feeding increased body weight and visceral adiposity, liver triglyceride and cholesterol concentrations, and worsened glucose tolerance. Although the high-fat diet did not affect renal function, it significantly worsened cardiac function in a subset of SHR rats. Empagliflozin reduced body weight gain but not visceral fat deposition. It also improved glucose sensitivity and several metabolic parameters (plasma insulin, uric acid, and HDL cholesterol). In the liver, empagliflozin reduced ectopic lipid accumulation, lipoperoxidation, inflammation and pro-inflammatory HETEs, while increasing anti-inflammatory EETs. In addition, empagliflozin improved cardiac function (systolic, diastolic and pumping) independent of blood pressure. The results of our study suggest that hepatoprotection plays a decisive role in the beneficial effects of empagliflozin in preventing the progression of cardiac dysfunction induced by high-fat diet feeding.

• MeSH
• benzhydrylové sloučeniny * farmakologie   MeSH
• dieta s vysokým obsahem tuků * škodlivé účinky   MeSH
• glifloziny * farmakologie   MeSH
• glukosidy * farmakologie   MeSH
• hypertenze farmakoterapie   MeSH
• játra * účinky léků   metabolismus   patologie   MeSH
• kardiotonika farmakologie   MeSH
• krevní glukóza metabolismus   účinky léků   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu rattus MeSH
• ledviny účinky léků   metabolismus   patologie   MeSH
• ochranné látky farmakologie   MeSH
• potkani inbrední SHR * MeSH
• ztučnělá játra prevence a kontrola   farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Chronic treatment with acetylcholinesterase inhibitors may be a promising therapeutic strategy for treatment of cardiovascular diseases. The aim of our study was to analyze the changes in blood pressure (BP) and heart rate (HR) during 14 days of treatment with two different acetylcholinesterase inhibitors - pyridostigmine (PYR) having only peripheral effects or donepezil (DON) with both peripheral and central effects. In addition, we studied their effects on the cardiovascular response to restraint stress and on sympathovagal control of HR in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). SHR were characterized by elevated BP and increased low-frequency component of systolic BP variability (LF-SBPV), but their cardiac vagal tone and HR variability (HRV) were reduced compared with WKY. Chronic treatment with either acetylcholinesterase inhibitor decreased HR and increased HRV in both strains. PYR treatment slightly decreased BP and LF-SBPV in the dark phase of the day. Neither drug significantly altered BP response to stress, but PYR attenuated HR increase during restraint stress. Regarding sympathovagal balance, acute methylatropine administration caused a greater increase of HR in WKY than in SHR. Chronic PYR or DON treatment enhanced HRV and HR response to methylatropine (vagal tone) in WKY, whereas PYR but not DON treatment potentiated HRV and vagal tone in SHR. In conclusion, vagal tone was lower in SHR compared with WKY, but was enhanced by chronic PYR treatment in both strains. Thus, chronic peripheral, but not central, acetylcholinesterase inhibition has major effects on HR and its variability in both normotensive and hypertensive rats.

• MeSH
• acetylcholinesterasa MeSH
• cholinesterasové inhibitory farmakologie   terapeutické užití   MeSH
• deriváty atropinu * MeSH
• donepezil farmakologie   MeSH
• hypertenze * farmakoterapie   MeSH
• krevní tlak MeSH
• krysa rodu rattus MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• pyridostigmin-bromid * farmakologie   MeSH
• srdeční frekvence MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Nestin is a unique intermediate filament expressed for a short period in the developing heart. It was also documented in several cell types of the adult myocardium under pathological conditions such as myocardial infarction or fibrosis. However, circumstances of nestin re-occurrence in the diseased or aging heart have not been elucidated yet. In this work we immunohistochemically detected nestin to determine its expression and distribution pattern in the left ventricular myocardium of normotensive Wistar Kyoto (WKY) rats and in the hypertrophic ones of spontaneously hypertensive (SHR) rats, both at the age of 1 and 1.5 year. No nestin+ cells were identified in the intact myocardium of 1-year-old WKY rats, whereas in the aged 1.5-year-old WKY rats nestin+ endothelial cells in some blood vessels were discovered. In the hypertrophic myocardium of all SHR rats, nestin was rarely detected in desmin+ vimentin- cardiomyocytes and in some vimentin+ interstitial cells often accumulated in clusters, varying in intensity of desmin immunoreactivity. Moreover, nestin was infrequently expressed in the endothelial cells of some myocardial blood vessels in 1-year-old SHR rats, but not in 1.5-year-old ones. Quantitative image analysis of nestin expression in the myocardium confirmed significant increase in 1.5-year-old WKY rats and in SHR rats of both ages compared to the intact 1-year-old WKY rats. This study firstly documents nestin re-expression indicating cytoskeletal remodelling in different cell types of the aging intact and chronically pressure over-loaded hypertrophied myocardium. Our findings confirm nestin involvement in complex changes during myocardial hypertrophy and progressive aging.

• MeSH
• hypertenze metabolismus   patologie   MeSH
• kardiomyocyty metabolismus   patologie   MeSH
• krysa rodu rattus MeSH
• myokard * metabolismus   patologie   MeSH
• nestin * metabolismus   MeSH
• potkani inbrední SHR * MeSH
• potkani inbrední WKY * MeSH
• proteiny intermediálních filament metabolismus   MeSH
• proteiny nervové tkáně metabolismus   MeSH
• stárnutí * metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH