Combination of chronic kidney disease (CKD) and heart failure (HF) results in extremely high morbidity and mortality. The current guideline-directed medical therapy is rarely effective and new therapeutic approaches are urgently needed. The study was designed to examine if renal denervation (RDN) will exhibit long-standing beneficial effects on the HF- and CKD-related morbidity and mortality. Fawn-hooded hypertensive rats (FHH) served as a genetic model of CKD and fawn-hooded low-pressure rats (FHL) without CKD served as controls. HF was induced by creation of aorto-caval fistula (ACF). RDN was performed 28 days after creation of ACF and the follow-up period was 70 days. ACF FHH subjected to sham-RDN had survival rate of 34 % i.e. significantly lower than 79 % observed in sham-denervated ACF FHL. RDN did not improve the condition and the final survival rate, both in ACF FHL and in ACF FHH. In FHH basal albuminuria was markedly higher than in FHL, and further increased throughout the study. RDN did not lower albuminuria and did not reduce renal glomerular damage in FHH. In these rats creation of ACF resulted in marked bilateral cardiac hypertrophy and alterations of cardiac connexin-43, however, RDN did not modify any of the cardiac parameters. Our present results further support the notion that kidney damage aggravates the HF-related morbidity and mortality. Moreover, it is clear that in the ACF FHH model of combined CKD and HF, RDN does not exhibit any important renoprotective or cardioprotective effects and does not reduce mortality. Key words Chronic kidney disease, Heart failure, Renal denervation, Fawn-hooded hypertensive rats.

• MeSH
• Denervation methods   MeSH
• Hypertension * physiopathology   complications   MeSH
• Cardio-Renal Syndrome * physiopathology   surgery   etiology   MeSH
• Rats MeSH
• Kidney * innervation   MeSH
• Disease Models, Animal MeSH
• Sympathectomy * methods   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Heart failure (HF) is life-threatening disease due to electro-mechanical dysfunction associated with hemodynamic overload, while alterations of extracellular matrix (ECM) along with perturbed connexin-43 (Cx43) might be key factors involved. We aimed to explore a dual impact of pressure, and volume overload due to aorto-caval fistula (ACF) on Cx43 and ECM as well as effect of renin-angiotensin blockade. Hypertensive Ren-2 transgenic rats (TGR) and normotensive Hannover Sprague-Dawley rats (HSD) that underwent ACF were treated for 15-weeks with trandolapril or losartan. Blood serum and heart tissue samples of the right (RV) and left ventricles (LV) were used for analyses. ACF-HF increased RV, LV and lung mass in HSD and to lesser extent in TGR, while treatment attenuated it and normalized serum ANP, BNP-45 and TBARS. Cx43 protein and its ser368 variant along with PKCε were lower in TGR vs HSD and suppressed in both rat strains due to ACF but prevented more by trandolapril. Pro-hypertrophic PKCδ, collagen I and hydroxyproline were elevated in TGR and increased due to ACF in both rat strains. While SMAD2/3 and MMP2 levels were lower in TGR vs HSD and reduced due to ACF in both strains. Findings point out the strain-related differences in response to volume overload. Disorders of Cx43 and ECM signalling may contribute not only to HF but also to the formation of arrhythmogenic substrate. There is benefit of treatment with trandolapril and losartan indicating their pleiotropic anti-arrhythmic potential. It may provide novel input to therapy.

• MeSH
• Extracellular Matrix MeSH
• Hypertension * MeSH
• Connexin 43 genetics   MeSH
• Blood Pressure MeSH
• Rats MeSH
• Losartan pharmacology   MeSH
• Fistula * MeSH
• Rats, Sprague-Dawley MeSH
• Rats, Transgenic MeSH
• Renin MeSH
• Heart Failure * MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Connexin 43 MeSH
• Losartan MeSH
• Renin MeSH
• trandolapril MeSH Browser

We aimed to explore whether specific high-sucrose intake in older female rats affects myocardial electrical coupling protein, connexin-43 (Cx43), protein kinase C (PKC) signaling, miR-1 and miR-30a expression, and susceptibility of the heart to malignant arrhythmias. Possible benefit of the supplementation with melatonin (40 µg/ml/day) and omega-3 polyunsaturated fatty acids (Omacor, 25 g/kg of rat chow) was examined as well. Results have shown that 8 weeks lasting intake of 30% sucrose solution increased serum cholesterol, triglycerides, body weight, heart weight, and retroperitoneal adipose tissues. It was accompanied by downregulation of cardiac Cx43 and PKCε signaling along with an upregulation of myocardial PKCδ and miR-30a rendering the heart prone to ventricular arrhythmias. There was a clear benefit of melatonin or omega-3 PUFA supplementation due to their antiarrhythmic effects associated with the attenuation of myocardial Cx43, PKC, and miR-30a abnormalities as well as adiposity. The potential impact of these findings may be considerable, and suggests that high-sucrose intake impairs myocardial signaling mediated by Cx43 and PKC contributing to increased susceptibility of the older obese female rat hearts to malignant arrhythmias.

• Keywords
• Adiposity, Cardiac connexin-43, Female rats, Melatonin, Omega-3 PUFA, Sucrose diet, Ventricular fibrillation,
• MeSH
• Anti-Arrhythmia Agents metabolism   pharmacology   MeSH
• Connexin 43 metabolism   MeSH
• Dietary Sucrose adverse effects   MeSH
• Rats MeSH
• Melatonin metabolism   pharmacology   MeSH
• MicroRNAs metabolism   MeSH
• Myocardium metabolism   MeSH
• Obesity chemically induced   complications   drug therapy   metabolism   MeSH
• Fatty Acids, Omega-3 metabolism   pharmacology   MeSH
• Rats, Wistar MeSH
• Protein Kinase C-delta metabolism   MeSH
• Protein Kinase C-epsilon metabolism   MeSH
• Signal Transduction drug effects   MeSH
• Heart drug effects   MeSH
• Arrhythmias, Cardiac etiology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Arrhythmia Agents MeSH
• Connexin 43 MeSH
• Dietary Sucrose MeSH
• Melatonin MeSH
• MicroRNAs MeSH
• MIRN30 microRNA, rat MeSH Browser
• Fatty Acids, Omega-3 MeSH
• Protein Kinase C-delta MeSH
• Protein Kinase C-epsilon MeSH

We aimed to study the impact of altered thyroid status on myocardial expression of electrical coupling protein connexin-43 (Cx43), the susceptibility of rats to ventricular fibrillation (VF) and the effects of antioxidant-rich red palm oil (RPO). Adult male and female euthyroid, hyperthyroid (treated with T3/T4), hypothyroid (treated with methimazole) Wistar rats supplemented or not with RPO for 6 weeks were used. Function of isolated perfused heart and VF threshold were determined. Left ventricular tissue was used for assessment of mRNA and protein levels of Cx43, its phosphorylated forms and topology. Protein kinase C signaling (PKC) and gene transcripts of some proteins related to cardiac arrhythmias were assessed. Hyperthyroid state resulted in decrease of total and phosphorylated forms of Cx43 and suppression of PKC-ε expression in males and females, decrease of Cx43 mRNA in females, decrease of VF threshold and increase of functional parameters in male rat hearts. In contrast, hypothyroid status resulted in the increase of total and phosphorylated forms of Cx43, enhancement PKC-ε expression in males and females, increase of Cx43 mRNA in females, increase of VF threshold and decrease of functional parameters in male rat hearts. Function of the heart was partially normalized by RPO intake, which also enhanced myocardial Cx43 and PKC-ε expression as well as increased VF threshold in hyperthyroid male rats. We conclude that there is an inverse relationship between myocardial expression of Cx43, including its functional phosphorylated forms, and susceptibility of male rat hearts to VF in condition of altered thyroid status. RPO intake partly ameliorated adverse changes caused by excess of thyroid hormones.

• Keywords
• Cardiac arrhythmias, Connexin-43, PKC, Red palm oil, Thyroid hormones,
• MeSH
• Administration, Oral MeSH
• Connexin 43 antagonists & inhibitors   genetics   metabolism   MeSH
• Rats MeSH
• RNA, Messenger antagonists & inhibitors   genetics   metabolism   MeSH
• Myocardium metabolism   MeSH
• Plant Oils administration & dosage   pharmacology   MeSH
• Palm Oil MeSH
• Rats, Wistar MeSH
• Heart drug effects   MeSH
• Arrhythmias, Cardiac drug therapy   metabolism   MeSH
• Thyroid Gland drug effects   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Gja1 protein, rat MeSH Browser
• Connexin 43 MeSH
• RNA, Messenger MeSH
• Plant Oils MeSH
• Palm Oil MeSH