L-Carnitine improves mechanical responses of cardiomyocytes and restores Ca homeostasis during aging.

L-Carnitine (β-hydroxy-γ-trimethylaminobutyric acid, LC) is a crucial molecule for the mitochondrial oxidation of fatty acids. It facilitates the transport of long-chain fatty acids into the mitochondrial matrix. The reduction in LC levels during the aging process has been linked to numerous cardiovascular disorders, including contractility dysfunction, and disrupted intracellular Ca homeostasis.

Vitamin D3 Promotes Structural and Functional Recovery After Vincristine-Induced Peripheral Neuropathy in Rats: An Experimental Study.

Background Vincristine-induced peripheral neuropathy (VIPN) is a distal axonopathy characterized by the loss of distal myelinated axons. This study aimed to assess the potential neuroregenerative roles of vitamin D3 using functional and electron microscopic analyses in a rat model of VIPN. Methodology A total of 40 female Wistar rats were randomly divided into four main groups: Group 1 (control, = 10), Group 2 (vincristine, = 10), Group 3 (vincristine + vitamin D3, = 10), and Group 4 (vincristine + vehicle, = 10).

Pharmacological blockade of angiotensin II receptor restores diabetes-associated reduction of store operated Ca entry in adult cardiomyocytes.

The store-operated Ca entry (SOCE) represents an important route for generating cellular Ca signals that are implicated in physiological and various pathological scenarios that include diabetic cardiomyopathy (DM-CMP) which is well known to have Ca dysregulation among other salient features. In this study, we investigated the role of SOCE in Ca handling of cardiomyocytes obtained from adult male Wistar rats that were made diabetic by intraperitoneal administration of streptozotocin (STZ 50 mg/kg). We also included another group of rats with diabetes induced by STZ administration but received an angiotensin II receptor blocker - losartan.

Sulfur Dioxide Derivative Prevents the Prolongation of Action Potential During the Isoproterenol-Induced Hypertrophy of Rat Cardiomyocytes.

Exogenous SO2 is toxic especially to the pulmonary and cardiovascular system, similar to nitric-oxide, carbon-monoxide, and hydrogen-sulfide. Endogenous SO2 is produced in many cell types. The SO2 content of the rat heart has been observed to substantially decrease during isoproterenol-induced hypertrophy.

Concealed role of red blood cells in pathogenesis of pulmonary arterial hypertension: Decreased red blood cell nitric oxide generation and effect of Rho-Kinase inhibitor fasudil.

Background: Pulmonary arterial hypertension (PAH) is a devastating disease characterized with alterations in pulmonary vasculature yielding increased pulmonary arterial resistance. Emerging evidences suggest important regulatory roles of red blood cells (RBCs) on nitric oxide (NO) bioavailability, mainly by modulating their endothelial nitric oxide synthase (eNOS) enzyme activity.

Objective: The aim of this pilot study was to evaluate the alterations in RBC eNOS activity and intracellular NO generation in PAH patients and the modulatory effects of Rho-Kinase (ROCK) inhibitors.

Comparison of nerve conduction velocity distribution methods by cold exposure and ischemia.

Purpose: Non-invasive estimation of the conduction velocity distribution (CVD) of a peripheral nerve has the potential to both improve clinical diagnoses of pathology and to observe the progress of the disease or the efficacy of treatments. Comparisons were made of the performance of three non-invasive CVD estimation methods proposed by independent research groups on peripheral nerve bundles under different conditions.

Methods: The first method (Cummins) uses a nerve compound action potential (CAP) with temporal dispersion and a mathematical single fiber action potential (SFAP).

Mathematical model of the ventricular action potential and effects of isoproterenol-induced cardiac hypertrophy in rats.

Mathematical action potential (AP) modeling is a well-established but still-developing area of research to better understand physiological and pathological processes. In particular, changes in AP mechanisms in the isoproterenol (ISO) -induced hypertrophic heart model are incompletely understood. Here we present a mathematical model of the rat AP based on recordings from rat ventricular myocytes.

Rho-kinase is a negative regulator of red blood cell eNOS under basal conditions.

Background: Rho-kinase, an effector of the small GTPase RhoA, is known to be a novel inhibitory regulator of eNOS in endothelial cells under basal conditions and disease states. However, although RBC possesses active RhoA/Rho-kinase pathway, Rho-kinase mediated eNOS regulation has not been investigated in RBC, so far.

Objective: The aim of the present study is to investigate whether eNOS activity is regulated by Rho-kinase under basal conditions and to evaluate whether inhibition of this enzyme causes eNOS activation and intracellular NO production in RBC.

Extracellular ATP activates eNOS and increases intracellular NO generation in Red Blood Cells.

Background: It has been well documented that ATP activates NOS enzymes and causes increased NO production in several cell types. Although RBC known to possesses eNOS enzyme activity, it has not been investigated whether RBC eNOS could be induced by extracellular ATP.

Objective: The aim of the present study is to evaluate extracellular ATP mediated eNOS activation and NO production in RBC.

Effect of magnesium supplementation on blood rheology in NOS inhibition-induced hypertension model.

This study investigated the effects of magnesium on blood rheological properties and blood pressure in nitric oxide synthase (NOS) inhibition-induced hypertension model. Hypertension was induced by oral administration of the nonselective NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME, 25 mg/kg/day) for 6 weeks and systolic blood pressure was measured by the tail-cuff method. The groups receiving magnesium supplementation were fed with rat chow containing 0.

Melatonin leads to axonal regeneration, reduction in oxidative stress, and improved functional recovery following sciatic nerve injury.

Despite recent advances in microsurgical techniques and equipments, recovery of function following repair of transected nerves often remains suboptimal. Contrary to traumatic injuries vascular damage that causes peripheral nerve injury has not been well-documented in the literature. In the present study a total of 40 female rats were randomly divided into four groups: Group 1: intact controls (n: 10), Group 2: sham-operated (n: 10), Group 3: vehicle-treated (n: 10), Group 4: melatonin-treated (n: 10).

Serum lipid peroxidation markers are correlated with those in brain samples in different stress models.

Objective: Stress can stimulate increased production of oxygen radicals. We investigated the correlations between serum levels of lipid peroxidation markers and those in brain samples in different stress models.

Methods: Animals (n = 96) were divided equally into eight groups: a control group and groups treated with vitamin E (Vit E); exposed to immobilisation stress; exposed to immobilisation stress and treated with Vit E; exposed to cold stress; exposed to cold stress and treated with Vit E; exposed to both immobilisation and cold stress; and a final group exposed to both immobilisation and cold stress and treated with Vit E.

Long-term administration of rosuvastatin prevents contractile and electrical remodelling of diabetic rat heart.

In recent years, many findings have been presented about the potential benefit of statin therapy on diabetes-induced cardiovascular complications. Cardioprotective effects of statins were suggested to be mediated at least in part through inhibition of small GTPases, particularly those of the Rho family. The present study was designed to examine whether rosuvastatin can improve electrical remodeling and contractile dysfunction in type 1 diabetic rat heart via modulation of RhoA pathway.

Effect of angiotensin II type 1 receptor blocker on osteoporotic rat femurs.

Background: Osteoblasts and osteoclasts are known to express Ang II type I (AT1) receptor in cell cultures, suggesting the existence of local renin-angiotensin system (RAS) in bone. This study was designed to investigate the effects of losartan as AT1 receptor blocker on ovariectomized rats' femur.

Methods: Losartan (5 mg/kg/day) was administered via oral gavage for 8 weeks.

Shear stress activation of nitric oxide synthase and increased nitric oxide levels in human red blood cells.

Red blood cells (RBC) play an important role in the balance between generation and scavenging of nitric oxide (NO) and hence its local bioavailability and influence on vasomotor control. Previous studies have reported increased NO levels in RBC suspensions subsequent to exposure to shear forces; the present study was designed to further investigate changes in intracellular NO concentration and possible mechanisms involved for RBC exposed to well-controlled shear forces. Attached human RBC were subjected to shear stresses up to 0.

Sex-related effects on diabetes-induced alterations in calcium release in the rat heart.

The present study was designed to determine whether the properties of local Ca(2+) release and its related regulatory mechanisms might provide insight into the role of sex differences in heart functions of control and streptozotocin-induced diabetic adult rats. Left ventricular developed pressure, the rates of pressure development and decay (+/-dP/dt), basal intracellular Ca(2+) level ([Ca(2+)](i)), and spatiotemporal parameters of [Ca(2+)](i) transients were found to be similar in male and female control rats. However, spatiotemporal parameters of Ca(2+) sparks in cardiomyocytes isolated from control females were significantly larger and slower than those in control males.

Gender related differential effects of Omega-3E treatment on diabetes-induced left ventricular dysfunction.

The present study was designed to determine whether there are beneficial effects of intake of Omega-3E (containing 70% pure omega-3 and 2% natural vitamin E) in cardiac dysfunction of diabetic rats. We also examined whether there are gender-related differences in the responses to the intake of Omega-3E on the heart dysfunction. Experiments were performed by using Langendorff-perfused hearts from normal, diabetic (with 50 mg/kg streptozotocin), and Omega-3E (50 mg/kg body weight/day) treated diabetic 3-month-old Wistar rats.

Restoration of diabetes-induced abnormal local Ca2+ release in cardiomyocytes by angiotensin II receptor blockade.

Stimulation of local renin-angiotensin system and increased levels of oxidants characterize the diabetic heart. Downregulation of ANG II type 1 receptors (AT(1)) and enhancement in PKC activity in the heart point out the role of AT(1) blockers in diabetes. The purpose of this study was to evaluate a potential role of an AT(1) blocker, candesartan, on abnormal Ca(2+) release mechanisms and its relationship with PKC in the cardiomyocytes from streptozotocin-induced diabetic rats.

Effects of diabetes on ryanodine receptor Ca release channel (RyR2) and Ca2+ homeostasis in rat heart.

The defects identified in the mechanical activity of the hearts from type 1 diabetic animals include alteration of Ca2+ signaling via changes in critical processes that regulate intracellular Ca2+ concentration. These defects result partially from a dysfunction of cardiac ryanodine receptor calcium release channel (RyR2). The present study was designed to determine whether the properties of the Ca2+ sparks might provide insight into the role of RyR2 in the altered Ca2+ signaling in cardiomyocytes from diabetic animals when they were analyzed together with Ca2+ transients.

Altered mechanical and electrical activities of the diabetic heart: Possible use of new therapeutics?

Diabetes mellitus produces functional, biochemical and morphological myocardial abnormalities independent of coronary atherosclerosis and hypertension. Although tight glycemic control decreases the risk of heart failure in patients with diabetes, the effects of different diabetic treatment regimens on heart failure have yet to be determined and remain subject to further investigation.Evidence suggests that reactive oxygen species play an important role in the development of diabetic cardiomyopathy, and antioxidants have been used to reduce cardiomyopathy in patients with diabetes.

Interpretation of relevance of sodium-calcium exchange in action potential of diabetic rat heart by mathematical model.

Sarcolemmal Na+-Ca2+ exchange plays a central role in ion transport of the myocardium and the current carried with it contributes to the late phase of the action potential (AP) besides the contribution of outward K+-currents. In this study, the mathematical model for AP of the diabetic rat ventricular myocytes [34] was modified and used for the diabetic rat papillary muscle. We used our experimentally measured values of two K+-currents; transient outward current, Ito and steady-state outward current, Iss, as well as L-type Ca2+-current, I(CaL), then compared with the simulated values.

Selenium-induced alterations in ionic currents of rat cardiomyocytes.

In the present study, rats were treated with sodium selenite (5 micromol/kg body weight/day, ip) for 4 weeks and the parameters of contractile activity, action potential, L-type Ca2+-current (ICaL), as well as transient outward (Ito), inward rectifier (IK1), and steady state (Iss) K+-currents were investigated. Sodium selenite treatment increased rat blood glucose level and lowered plasma insulin level, significantly. This treatment also caused slightly prolongation in action potential with no significant effects on spontaneous contraction parameters and intracellular Ca2+ transients of the heart preparations.

Effect of donepezil on EEG spectral analysis in Alzheimer's disease.

EEG spectral analysis allows a quantitative analysis of changes in the frequency bands during disease progression in Alzheimer's disease (AD) and could be used to monitor treatment and disease progression. Eighteen patients with probable AD were evaluated by Folstein Mini Mental State Examination (MMSE) and EEG spectral analysis before donepezil treatment, 2 months after 5 mg/day and 4 months after the dose was raised to 10 mg/day. EEG evaluations were done in 4 derivations (T3-T5, T4-T6, C3-P3, C4-P4).

Effect of immobilization and cold stress on visual evoked potentials.

The main aim of our research was to study the effects of immobilization and/or cold stress on amplitudes and latencies of visual evoked potentials (VEPs) and thiobarbituric acid reactive substances (TBARS). Forty healthy male albino rats, aged three months, were used. The rats were equally divided into four groups: Control group (C), the group exposed to cold stress (CS), the group exposed to immobilization stress (IS), and the group exposed to both cold and immobilization stress (CIS).

The effect of vitamin E on stress-induced changes in visual evoked potentials (VEPs) in rats exposed to different experimental stress models.

Purpose: The aim of the study was to investigate the effects of vitamin E on stress-induced changes in visual evoked potentials (VEPs) and lipid peroxidation.

Methods: Eight experimental groups of 10 rats per group were formed. These consisted of the control group (C); the group treated with vitamin E (E); groups exposed to cold stress (CS), immobilization stress (IS) and both cold and immobilization stress (CIS), and groups exposed to equivalent stresses and treated with vitamin E (CSE, ISE, CISE).