Age- and sex-dependent cardiovascular impact of maternal perinatal stress and altered dopaminergic metabolism in the medulla oblongata of the offspring.

M Maternal Major Depressive Disorder with Peripartum Onset presents health risks to the mother and the developing fetus. Using a rat model of chronic mild stress, we previously reported on the neurodevelopmental impact of maternal perinatal stress on their offspring; the present study examined the cardiovascular impact of maternal perinatal stress on their offspring. The cardiovascular impact was assessed in terms of blood pressure and echocardiographic parameters. The results examined by a three-way ANOVA showed a significant association of cardiovascular parameters with maternal perinatal stress, and offspring sex and age. Increased blood pressure was observed in adolescent female and adult male offspring of stress-exposed dams. Echocardiography showed an increase in left atrial dimension and a reduction in left ventricular systolic function in adolescent stress-exposed female offspring. Increased interventricular septum thickness at end-diastole and left ventricular diastolic dysfunction were observed in adult stress-exposed male offspring. The underlying mechanisms of cardiovascular impact were examined in stress-exposed adult offspring by assessing the levels of neurotransmitters and their metabolites in the medulla oblongata using high-performance liquid chromatography. A significant decrease in homovanillic acid, a dopamine metabolite and indicator of dopaminergic activity, was observed in adult stress-exposed female offspring. These results suggest a significant sex- and age-dependent impact of maternal stress during the peripartum period on the cardiovascular system in the offspring that extends to adulthood and suggests a multigenerational effect. The presented data urgently need a follow-up to confirm its potential clinical and public health relevance.

The Interaction of Vasopressin with Hormones of the Hypothalamo-Pituitary-Adrenal Axis: The Significance for Therapeutic Strategies in Cardiovascular and Metabolic Diseases.

A large body of evidence indicates that vasopressin (AVP) and steroid hormones are frequently secreted together and closely cooperate in the regulation of blood pressure, metabolism, water-electrolyte balance, and behavior, thereby securing survival and the comfort of life. Vasopressin cooperates with hormones of the hypothalamo-pituitary-adrenal axis (HPA) at several levels through regulation of the release of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and multiple steroid hormones, as well as through interactions with steroids in the target organs. These interactions are facilitated by positive and negative feedback between specific components of the HPA. Altogether, AVP and the HPA cooperate closely as a coordinated functional AVP-HPA system. It has been shown that cooperation between AVP and steroid hormones may be affected by cellular stress combined with hypoxia, and by metabolic, cardiovascular, and respiratory disorders; neurogenic stress; and inflammation. Growing evidence indicates that central and peripheral interactions between AVP and steroid hormones are reprogrammed in cardiovascular and metabolic diseases and that these rearrangements exert either beneficial or harmful effects. The present review highlights specific mechanisms of the interactions between AVP and steroids at cellular and systemic levels and analyses the consequences of the inappropriate cooperation of various components of the AVP-HPA system for the pathogenesis of cardiovascular and metabolic diseases.

Bone turnover markers and muscle decay indicator in patients with proximal femur fracture - a case-control study.

Introduction: Fracture of the proximal femur is common in elderly patients, in fact threatening their lives. Age-related sarcopenia may be involved in the imbalance resulting in the injury. Handy and readily accessible biochemical tests would be useful to assess the musculoskeletal system condition in daily practice. The aim of the study was to determine whether there is any relation between muscle decay and fracture of the proximal femur and to assess bone quality in elderly patients. Material and methods: In the study 22 patients who represented the treatment group were hospitalized due to proximal femur fracture. Eighteen patients from the control group with no fracture in their history were admitted to the Internal Medicine Department. Anyone treated for osteoporosis, immune disease affecting protein balance, neoplasm, mental illness, heart failure, or myocardial infarction was excluded from the study. In every case a blood sample from an elbow vein was drawn, collected in EDTA-K2 tubes, and then centrifuged to separate plasma from the whole blood. Subsequently, the concentrations of C-terminal cross-linked telopeptide of type I collagen (CTX-I), sex hormone binding globulin (SHBG) and creatine kinase (CK) in plasma were determined using commercial enzyme-linked immunosorbent assays. Results: The CK plasma concentration differed between the patient groups (p = 0.011). The SHBG plasma concentration was significantly higher in the treatment group (p = 0.006), whereas a slight difference in CTX-I plasma concentration between the groups was found (p = 0.038). No significant correlations between plasma CK, SHBG or CTX-I were found (p > 0.05). Conclusions: Creatine kinase is actually not an appropriate marker for the clinical assessment of muscle tissue quality in patients with or at risk of proximal femur fracture. Analyzing the quality of bone tissue, we can conclude it was poorer in patients with proximal femur fracture than in the control group.

Evaluation of Nitrosative/Oxidative Stress and Inflammation in Heart Failure with Preserved and Reduced Ejection Fraction.

Heart failure (HF) is a complex syndrome characterized by impaired cardiac function. Two common subtypes of HF include heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). In this study, we aimed to evaluate and compare the plasma levels of 3-nitrotyrosine (3-NT)-as a marker of nitrosative/oxidative stress and myeloperoxidase (MPO)-as an indicator of inflammation between HFpEF and HFrEF. Twenty-seven patients diagnosed with HFpEF and twenty-two with HFrEF were enrolled in this study. Additionally, forty-one patients were recruited for the control group. An echocardiographic assessment was conducted, followed by the collection of blood samples from all participants. Subsequently, the levels of 3-NT and MPO were quantified using the ELISA method. Comprehensive clinical characteristics and medical histories were obtained. Circulating levels of 3-NT were significantly higher in the HFpEF patients than in the control and the HFrEF groups. Nitrosative/oxidative stress is significantly intensified in HFpEF but not in HFrEF.

A Review of the Roles of Apelin and ELABELA Peptide Ligands in Cardiovascular Disease, Including Heart Failure and Hypertension.

Apelin and ELABELA (ELA), which are peptides belonging to the adipokines group, are endogenous peptide ligands of their receptor, APJ, which together constitute the apelinergic system. The apelinergic system is expressed in numerous human tissues and organs, including the heart, blood vessels, adipose tissue, central nervous system, lungs, kidneys, and liver. Apelin, being the most widely studied member of the apelinergic system, plays a key role in the cardiovascular system and exerts a pleiotropic effect in tissues. Under physiological conditions, the peripheral actions of apelin include augmented cardiac contractility, increased left ventricular stroke volume, vasodilation, increased diuresis, and lowered systemic blood pressure. Multiple studies suggest that activation of the apelinergic system exerts beneficial effects on the treatment of cardiovascular diseases (CVD), including hypertension and heart failure, whereas the silencing of the apelin/APJ axis results in attenuation of inflammatory processes and prevents formation of atherosclerotic plaques. As numerous effects of apelin are not entirely explained, further studies of the cardiovascular actions of apelin and ELA are necessary to help establish effective pharmacological treatments of CVDs. This article aims to review the roles of apelin and elabela peptide ligands in cardiovascular diseases, including heart failure and hypertension.

Remodeling and Fibrosis of the Cardiac Muscle in the Course of Obesity-Pathogenesis and Involvement of the Extracellular Matrix.

Obesity is a growing epidemiological problem, as two-thirds of the adult population are carrying excess weight. It is a risk factor for the development of cardiovascular diseases (hypertension, ischemic heart disease, myocardial infarct, and atrial fibrillation). It has also been shown that chronic obesity in people may be a cause for the development of heart failure with preserved ejection fraction (HFpEF), whose components include cellular hypertrophy, left ventricular diastolic dysfunction, and increased extracellular collagen deposition. Several animal models with induced obesity, via the administration of a high-fat diet, also developed increased heart fibrosis as a result of extracellular collagen accumulation. Excessive collagen deposition in the extracellular matrix (ECM) in the course of obesity may increase the stiffness of the myocardium and thereby deteriorate the heart diastolic function and facilitate the occurrence of HFpEF. In this review, we include a rationale for that process, including a discussion about possible putative factors (such as increased renin-angiotensin-aldosterone activity, sympathetic overdrive, hemodynamic alterations, hypoadiponectinemia, hyperleptinemia, and concomitant heart diseases). To address the topic clearly, we include a description of the fundamentals of ECM turnover, as well as a summary of studies assessing collagen deposition in obese individuals.

The effect of depressive-like behavior in pregnant rat dams on the cardiovascular system in their offspring.

Maternal depression during pregnancy affects 18-20% of women and is often associated with comorbidities and adverse health outcomes for the offspring. We have previously reported on neurodevelopmental delays in a rat model of maternal depression during pregnancy; current report presents echocardiographic (ECHO) data derived from the same experiment and focuses on cardiovascular response in the offspring to maternal perinatal depression. Rat dams were exposed to chronic mild stress (CMS) with repeated restraint before pregnancy. Cardiac functions were assessed in the 35-day-old offspring, derived from control (CO, n = 11) and stress-exposed dams (SO, n = 16), using echocardiography (ECHO). The expression of cardiac failure marker - B-type natriuretic peptide (BNP) was measured in the myocardium by RT-PCR. ECHO analysis revealed a significant increase in heart rate (HR) and impairment of left ventricular diastolic function parameters. Importantly, a significant increase in mitral valve flow E wave velocity (MVE) and a decrease of mitral valve deceleration time of E wave (MV DT) were observed in SO. The expression of BNP was significantly higher in SO. These results suggest that maternal depression during pregnancy impacts offspring cardiovascular function, and specifically the diastolic cardiac functions of the left ventricle.

The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress.

PURPOSE OF REVIEW: Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101-103 cells/g in the upper intestine to 1011-1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer. RECENT FINDINGS: Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of "metabolic endotoxemia," which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

Central interaction between the apelinergic and vasopressinergic systems in the regulation of the haemodynamic parameters in rats maintained on a high-fat diet.

A high-fat diet can affect the central activity of the apelinergic and vasopressinergic systems, which can have a significant impact on cardiovascular regulation. The aim of the study was to investigate the role of the central interaction between apelin and vasopressin in the regulation of the cardiovascular system in Sprague Dawley rats maintained on a normal-fat diet (NFD) or on a high-fat diet (HFD). The animals were instrumented with a cannula implanted into the left cerebral ventricle for intracerebroventricular (ICV) infusions of saline (0.9% NaCl), apelin-13 (APLN-13), V1a receptor antagonist (V1aRANT) APJ receptor antagonist (F13A), vasopressin (AVP); and with a catheter placed within the femoral artery for mean arterial blood pressure and heart rate monitoring. Blood, the hypothalamus and the medulla oblongata were collected for biochemical analysis. The hypertensive effect of APLN-13 was blocked by a prior ICV infusion of V1aRANT, only in the NFD rats. However, the hypertensive effect of AVP was blocked by the prior ICV infusion of F13A in both the NFD and HFD rats. A HFD caused an increase in the protein level of APJ and V1a receptors, both in the hypothalamus and the medulla oblongata. This study confirms the presence of an interaction between both peptides in the central regulation of the cardiovascular system in rats on a NFD or a HFD.

Interaction of Orexin A and Vasopressin in the Brain Plays a Role in Blood Pressure Regulation in WKY and SHR Rats.

BACKGROUND Orexin A (OXA) and vasopressin (AVP) exert a central hypertensive effect due to an increase in sympathetic nerve activity. To date, little is known about the interaction of these 2 neuropeptides in the central regulation of blood pressure. The present study compared the consequences of infusion into the left cerebral ventricle (ICV) of OXA on mean arterial blood pressure (MABP) in normotensive (WKY) and spontaneously hypertensive (SHR) rats, and explored whether the central pressor action of OXA in these 2 strains depends on activation of brain AVP V1a receptors (V1aR). MATERIAL AND METHODS Ten groups of experiments were performed on 12-week-old WKY and SHR rats implanted with ICV cannulas for infusion of OXA (3 nmol) and V1aR antagonist (V1aRANT, 500 ng), administered separately and together. Levels of V1aR and OXR in the medulla oblongata of WKY and SHR rats were compared in separate series. RESULTS We found that: 1) OXA significantly increased MABP only in WKY rats, 2) V1aRANT prevented an increase in MABP induced by OXA in WKY rats and decreased MABP in SHR rats, 3) OXA abolished the hypotensive action of V1aRANT in SHR rats, and 4) SHR rats had significantly higher levels of OX1R and V1aR proteins and OX1R mRNA in the brain medulla. CONCLUSIONS The present study shows that OXA and AVP can interact in the brain to affect blood pressure regulation, and that this interaction differs in normotension and hypertension.

Autonomic nervous system in Takotsubo syndrome.

Takotsubo syndrome (TTS) is an acute and usually reversible heart failure syndrome with symptoms resembling acute myocardial infarction, however, without obstruction of coronary arteries. In the majority of cases, TTS is preceded by emotional or physical stress and the disease concerns mainly postmenopausal women. Although several hypotheses have been introduced, the pathogenesis of TTS is controversial and still remains to be determined. As reported in recent studies, the role of the autonomic nervous system (ANS) seems to be pivotal in the pathogenesis of TTS. Therefore, the aim of this article is to summarize and discuss the current knowledge of the pathogenesis of TTS with a special focus on the ANS.

Common Genetic Variants Link the Abnormalities in the Gut-Brain Axis in Prematurity and Autism.

This review considers a link between prematurity and autism by comparing symptoms, physiological abnormalities, and behavior. It focuses on the bidirectional signaling between the microbiota and the brain, here defined as the microbiota-gut-vagus-heart-brain (MGVHB) axis and its systemic disruption accompanying altered neurodevelopment. Data derived from clinical and animal studies document increased prevalence of gastrointestinal, cardiovascular, cognitive, and behavioral symptoms in both premature and autistic children and suggest an incomplete maturation of the gut-blood barrier resulting in a "leaky gut," dysbiosis, abnormalities in vagal regulation of the heart, altered development of specific brain regions, and behavior. Furthermore, this review posits the hypothesis that common genetic variants link the abnormalities in the MGVHB axis in premature and autistic pathologies. This hypothesis is based on the recently identified common genetic variants: early B cell factor 1 (EBF1), selenocysteine tRNA-specific eukaryotic elongation factor (EEFSEC), and angiotensin II receptor type 2 (AGTR2), in the maternal and infant DNA samples, associated with risk of preterm birth and independently implicated in a risk of autism. We predict that the AGTR2 variants involved in the brain maturation and oxytocin-arginine-vasopressin (OXT-AVP) pathways, related to social behavior, will contribute to our understanding of the link between prematurity and autism paving a way to new therapies.

Dysregulation of the Renin-Angiotensin System and the Vasopressinergic System Interactions in Cardiovascular Disorders.

PURPOSE OF REVIEW: In many instances, the renin-angiotensin system (RAS) and the vasopressinergic system (VPS) are jointly activated by the same stimuli and engaged in the regulation of the same processes. RECENT FINDINGS: Angiotensin II (Ang II) and arginine vasopressin (AVP), which are the main active compounds of the RAS and the VPS, interact at several levels. Firstly, Ang II, acting on AT1 receptors (AT1R), plays a significant role in the release of AVP from vasopressinergic neurons and AVP, stimulating V1a receptors (V1aR), regulates the release of renin in the kidney. Secondly, Ang II and AVP, acting on AT1R and V1aR, respectively, exert vasoconstriction, increase cardiac contractility, stimulate the sympathoadrenal system, and elevate blood pressure. At the same time, they act antagonistically in the regulation of blood pressure by baroreflex. Thirdly, the cooperative action of Ang II acting on AT1R and AVP stimulating both V1aR and V2 receptors in the kidney is necessary for the appropriate regulation of renal blood flow and the efficient resorption of sodium and water. Furthermore, both peptides enhance the release of aldosterone and potentiate its action in the renal tubules. In this review, we (1) point attention to the role of the cooperative action of Ang II and AVP for the regulation of blood pressure and the water-electrolyte balance under physiological conditions, (2) present the subcellular mechanisms underlying interactions of these two peptides, and (3) provide evidence that dysregulation of the cooperative action of Ang II and AVP significantly contributes to the development of disturbances in the regulation of blood pressure and the water-electrolyte balance in cardiovascular diseases.

Copeptin Blood Content as a Diagnostic Marker of Chronic Kidney Disease.

Plasma content of copeptin increases with the advancement of chronic kidney disease (CKD). The purpose of this study was to evaluate copeptin content as a potential marker of CKD, as a single pathology or with coexisting heart failure. Seventy-six patients were divided into the following groups: Group 1 (control), without CKD and heart failure; Group 2, CKD stage 3a; Group 3, CKD stage 3b; Group 4, CKD stage 4; Group 5, CKD stage 5; and Group 6, CKD stage 3b and heart failure. For all patients, plasma concentrations of copeptin, creatinine, urea, cystatin C, sodium, C-reactive protein (CRP), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and blood pH were assessed. We found that plasma content of creatinine, urea, CRP, cystatin, NT-proBNP, and copeptin increased with CKD progression. Heart failure in CKD patients was not the cause of an appreciable increase of copeptin level. Copeptin/creatinine, copeptin/cystatin C ratios, and especially copeptin/eGFR ratio enhanced copeptin prognostic sensitivity concerning renal failure in CKD, compared with copeptin alone. The copeptin×NT-proBNP ratio decreased along CKD progression, reaching a nadir in the accompanying heart failure. In contradistinction, copeptin×NT-proBNP/creatinine ratio increased along CKD progression, reaching a peak in the accompanying heart failure. We conclude that copeptin is an important marker in CKD, but not so concerning heart failure in the disease. A decrease in copeptin×NT-proBNP and an increase in copeptin×NT-proBNP/creatinine ratio are useful markers of cardiac function decline in CKD.

Pathophysiological effect of bladder outlet obstruction on the urothelium.

Bladder outlet obstruction (BOO) and associated lower urinary tract symptoms are major urological issues that significantly affect patient's quality of life and may lead to severe complications. The prevalence of both is increasing each year, raising the burden to health system. Therefore, casual and symptomatic treatment should be of great importance. However, management of symptoms is often difficult as their pathophysiology is multifactorial and not well elucidated. Recently urothelium has gathered much attention as one of the potential causal agents. It has been suggested that in addition to its barrier function, urothelium regulates transport through blood-urine barrier and is a part of "sensory web" by which it modulates afferent input. In this review we focus on adjustment of urothelium related to BOO in terms of its ultrastructure, barrier and transport function, and impact on "sensory web."

Expression of matrix metalloproteinase enzymes in endometrium of women with abnormal uterine bleeding.

OBJECTIVES: Abnormal uterine bleeding (AUB) is caused by derangement of physiological processes of tissue growth, shedding and regeneration. It is known that interplay between metalloproteinases (MMP's) and tissue inhibitors of metalloproteinases (TIMP's) may play a crucial role in its occurrence. AIM: To define if expression of proMMP-2, MMP-2 and TIMP-1 in endometrium of women with AUB is dependent on steroid sex hormone concentration and histopathological picture. MATERIALS AND METHODS: Endometrial scraps were taken from 21 women with AUB and 19 controls. Samples were evaluated in light microscopy by a certified pathologist. Activity of proMMP-2 and MMP-2 proteins levels were evaluated by gelatin zymography and TIMP-1 by reversed zymography. The results has been correlated with serum estradiol and progesterone concentrations in linear regression model. RESULTS: Expression: of proMMP-2 in endometrium of women with AUB is correlated with estradiol concentration and inversely correlated with progesterone levels. It was significantly higher in women with dysfunctional endometrium (p<0.001). Expression of MMP-2 was highest in women with endometrial polyps and longer bleeding (p<0.01), while expression of TIMP-1 was independent from hormone concentration. CONCLUSION: Lack of correlation between proMMP-2 and MMP-2 levels suggest different pathway of their activation in AUB. ProMMP-2 is up regulated by estradiol and down regulated by progesterone while MMP-2 levels increase with the length of bleeding.

Role of Nitric Oxide Pathway in Development and Progression of Chronic Kidney Disease in Rats Sensitive and Resistant to its Occurrence in an Experimental Model of 5/6 Nephrectomy.

BACKGROUND Understanding the mechanisms conditioning development of chronic kidney disease (CKD) is still a challenge. The aim of this study was to evaluate the activity of the intrarenal nitric oxide (NO) pathway in the context of sensitivity or resistance of different animal strains to the development and degree of renal failure. MATERIAL AND METHODS Two rat strains were used: Wistar (WR) and Sprague-Dawley rats (SDR) in a model of CKD - 5/6 nephrectomy. We assessed parameters of renal failure and expression of nitric oxide synthase (NOS) isoforms in renal cortex and medulla. RESULTS We did not observe renal failure in WR, and CKD developed in SDR with increase of creatinine and urea concentration as well as decrease of diuresis and glomerular filtration. In the renal cortex, baseline expression of NOS2 was higher in WR than in SDR. 5/6 nephrectomy resulted in reduction of NOS2 in both strains and NOS3 in WR. In the renal medulla, baseline NOS2 expression was higher in SDR, and nephrectomy resulted in its decrease only in SDR. Although baseline NOS3 expression was higher in SDR, the NOS3 expression after nephrectomy was higher in WR rats. CONCLUSIONS In model of CKD - 5/6 nephrectomy, SDR proved to be sensitive and WR resistant to development of CKD. The intrarenal activity of the nitric oxide pathway was the factor that differentiated both strains. This mechanism may be responsible for insensitivity of WR to development of renal failure in this model of CKD.

The role of apelin in central cardiovascular regulation in rats with post-infarct heart failure maintained on a normal fat or high fat diet.

Based on the available literature, it can be assumed that in cases of post-infarct heart failure (HF) and obesity, a significant change in the central regulation of the cardiovascular system takes place with, among others, the involvement of the apelinergic system. The main objective of the present study was to clarify the role of apelin-13 in the central regulation of the cardiovascular system in Sprague Dawley rats with HF or sham operated (SO) and fed on a normal fat (NFD) or a high fat diet (HFD). The study was divided into two parts: Part I, hemodynamic studies; and Part II, biochemical and molecular studies. The animals were subjected to the following research procedures. Part I and II: feeding NFD or HFD; experimental induction of HF or SO; Part I: intracerebroventricular (ICV) infusion of the examined substances, monitoring of mean arterial blood pressure (MABP) and heart rate (HR); Part II: venous blood and tissue samples collected. ICV infusion of apelin-13 caused significantly higher changes in ΔMABP in the SO NFD group. No changes were noted in ΔHR in any of the studied groups. Apelin and apelin receptor (APJ) mRNA expression in the brain and adipose tissues was higher in the HF rats. HFD causes significant increase in expression of apelin and APJ mRNA in the left ventricle. In conclusion, HF and HFD appear to play an important role in modifying the activity of the central apelinergic system and significant changes in mRNA expression of apelin and APJ receptor.

High-fat diet and chronic stress reduce central pressor and tachycardic effects of apelin in Sprague-Dawley rats.

Central application of apelin elevates blood pressure and influences neuroendocrine responses to stress and food consumption. However, it is not known whether the central cardiovascular effects of apelin depend also on caloric intake or chronic stress. The purpose of the present study was to determine the effects of intracerebroventricular administration of apelin on blood pressure (mean arterial blood pressure) and heart rate in conscious Sprague-Dawley rats consuming either a normal-fat diet (NFD) or high-fat diet (HFD) for 12 weeks. During the last 4 weeks of the food regime, the rats were exposed (NFDS and HFDS groups) or not exposed (NFDNS and HFDNS groups) to chronic stress. Each group was divided into two subgroups receiving intracerebroventricular infusions of either vehicle or apelin. Apelin elicited significant increase of mean arterial blood pressure and heart rate in the NFDNS rats. This effect was abolished in the HFDNS, HFDS and NFDS groups. HFD resulted in a significant elevation of blood concentrations of total cholesterol, triglycerides glucose and insulin. Chronic stress reduced plasma concentration of total and high-density lipoprotein cholesterol, and increased plasma corticosterone concentration and APJ receptor mRNA expression in the hypothalamus, whereas a combination of a HFD with chronic stress resulted in the elevation of plasma triglycerides, total cholesterol and low-density lipoprotein cholesterol, and in increased plasma corticosterone concentration, apelin concentration and APJ receptor mRNA expression in the hypothalamus. It is concluded that a HFD and chronic stress result in significant suppression of the central pressor action of apelin, and cause significant though not unidirectional changes of metabolic and endocrine parameters.

Sphingolipids in cardiovascular diseases and metabolic disorders.

Many investigations suggest the pivotal role of sphingolipids in the pathogenesis of lifestyle diseases such as myocardial infarction, hypertension, stroke, diabetes mellitus type 2 and obesity. Some studies suggest that sphingolipids are important factors in cellular signal transduction. They serve as biologically active components of cell membrane and are involved in many processes such as proliferation, maturation and apoptosis. Recently, ceramide and sphingosine-1-phosphate have become the target of many investigations. Ceramide is generated in three metabolic pathways and many factors induce its production as a cellular stress response. Ceramide has proapoptotic properties and acts as a precursor for many other sphingolipids. Sphingosine-1-phosphate is a ceramide derivative, acting antiapoptotically and mitogenically and it is importantly involved in cardioprotection. Further research on the involvement of sphingolipids in cellular pathophysiology may improve the prevention and therapy of lifestyle diseases.