Long-term treatment with kefir probiotics ameliorates cardiac function in spontaneously hypertensive rats.

This work evaluated the effects of long-term kefir treatment in cardiac function (cardiac contractility and calcium-handling proteins) and the central nervous system (CNS) control of the sympathetic signaling in spontaneously hypertensive rats (SHR). Male normotensive rats [Wistar Kyoto rats (WKYs)] and SHRs were divided into three groups: WKYs and SHRs treated with vehicle, and SHRs treated with milk fermented by the grains of kefir (5%; SHR-Kefir; oral gavage, 0.3 ml/100 g daily/9 weeks). At the end of treatment, mean arterial pressure (MAP) and heart rate (HR) were measured by direct arterial catheterization. Hemodynamic parameters (left ventricular systolic pressure, left ventricular isovolumetric relaxation time constant, maximal and minimal pressure decay) were acquired through a left ventricular catheter implantation. Left ventricle protein expressions of phospholamban (PLB), its phosphorylated form (p-PLB) and sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) were determined by Western blot. Tyrosine hydroxylase (TH) protein expression was evaluated via immunofluorescence within the paraventricular nucleus (PVN) of the hypothalamus and the rostral ventrolateral medulla (RVLM). SHR-Kefir group presented lower MAP and HR compared to SHRs. Kefir treatment ameliorated cardiac hypertrophy and promoted reduced expression of PLB, p-PLB and SERCA2a contractile proteins. Within the PVN and RVML, TH protein overexpression observed in SHRs was reduced by probiotic treatment. In addition, kefir improved cardiac hemodynamic parameters in SHR-treated animals. Altogether, the data show that long-term kefir treatment reduced blood pressure by mechanisms involving reduction of cardiac hypertrophy, improvement of cardiac contractility and calcium-handling proteins, and reduction in the CNS regulation of the sympathetic activity.

Long-term treatment with Nandrolone Decanoate impairs mesenteric vascular relaxation in both sedentary and exercised female rats.

Nandrolone Decanoate (ND) is an Anabolic Androgenic Steroid (AAS) that under abusive regimen can lead to multiple physiological adverse effects. Studies of AAS-mediated cardiovascular (CV) alterations were mostly taken from male subjects, even though women are also susceptible to the effects of AAS and gender-specific differences in susceptibility to vascular diseases exist. Here we investigate ND-induced vascular reactivity alterations in both sedentary and exercised female rats and whether these alterations depend on endothelium-derived factors. We show that chronic exposure of female Wistar rats to ND (20mg/Kg/week for 4weeks) impaired the vascular mesenteric bed (MVB) reactivity to vasodilator (acetylcholine) agonist. The endothelium-dependent Nitric Oxide (NO) component was reduced in ND-treated rats, whereas neither the endothelium-derived hyperpolarizing factor (EDHF) component nor prostanoids were altered in the MVBs. Endothelial dysfunction observed in ND-treated rats was associated with decreased eNOS (Ser1177) and Akt (Ser473) phosphorylation sites and upregulation of iNOS and NADPH oxidase expression. Exercise training by weight lifting in water did not improve the vascular alterations induced by ND treatment. ND treatment also significantly reduced the serum levels of estradiol in females, overriding its CV protective effect. These results help uncover the role of ND modulating endothelial function in the setting of CV disease caused by the abuse of AAS in females. If this translates to humans, young women abusing AAS can potentially lose the cardio protective effect rendered by estrogen and be more susceptible to CV alterations.

The selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen improve ANP levels and decrease nuclear translocation of NF-kB in estrogen-deficient rats.

BACKGROUND: The selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen are used for the treatment of osteoporosis and cancer, respectively, in women. The impairment of both the Atrial Natriuretic Peptide (ANP) cell signaling system and the translocation of nuclear factor-kappa B (NF-kB) to the cell nucleus are associated with detrimental cardiovascular effects and inflammation. The effects of SERMs on these parameters in the cardiac tissue of estrogen-deficient rats has not been reported. METHODS: We investigated the effects of raloxifene and tamoxifen on ANP signaling, p65 NF-kB nuclear translocation, cardiac histology and contractility. Female rats were divided into five groups: control (SHAM), ovariectomized (OVX), OVX-treated 17-ß-estradiol (E), OVX-treated raloxifene (RLX) and OVX-treated tamoxifen (TAM). The treatments started 21days after ovariectomy and continued for 14days. RESULTS: Ovariectomy reduced ANP mRNA in the left atrium (LA), decreased the content of ANP protein in the LA and in plasma, and increased the level of p65 NF-kB nuclear translocation in the left ventricle. Both 17-ß-estradiol and SERMs were able to reverse these alterations, which were induced by the estrogen deficient state. The hemodynamic and cardiac structural parameters analyzed in the present work were not modified by the interventions. CONCLUSIONS: Our study demonstrates, for the first time, the additional benefits of raloxifene and tamoxifen in an estrogen-deficient state. These include the normalization of plasmatic and cardiac ANP levels and cardiac p65 NF-kB translocation. Therefore, these treatments promote cardiovascular protection and may contribute to the prevention of cardiac dysfunction observed long-term in postmenopausal women.

Low dose of methyltestosterone in ovariectomised rats improves baroreflex sensitivity without geno- and cytotoxicity.

This study evaluated the effects of the isolated use of a low dose of methyltestosterone (MT) on cardiovascular reflexes and hormonal levels and its geno- and cytotoxic safety in ovariectomized rats. Female Wistar rats were divided into four groups (n = 6), respectively: SHAM (received vehicle methylcellulose 0.5%), SHAM + MT (received MT 0.05 mg/kg), OVX (received vehicle), and OVX + MT (received MT). Twenty-one days after ovariectomy, treatment was given orally daily for 28 days. The Bezold-Jarisch reflex (BJR) was analyzed by measuring the bradycardic and hypotensive responses elicited by phenylbiguanide (PBG) administration. The baroreflex sensitivity (BRS) was evaluated by phenylephrine and sodium nitroprussite. Myocyte hypertrophy was determined by morphometric analysis of H&E stained slides. Biochemical data were analyzed, as well as micronucleus assay. MT improved BRS and increased testosterone values, but did not change estradiol in the OVX group. MT did not promote changes in mean arterial pressure, heart rate, BJR, serum concentrations of troponin I, weight and histopathology of the heart. MT was able to restore the BRS in OVX rats. The geno- and cytotoxic safety of the MT was demonstrated by the absence of an increase in the micronucleus (PCEMN) or change in the ratio between normochromatic erythrocytes and polychromatic erythrocytes (NCE/PCE).

Morphometry to identify subtypes of leukocytes.

INTRODUCTION: Recent studies in image cytometry evaluated the replacement of specific markers by morphological parameters. The aim of this study was to develop and evaluate a method to identify subtypes of leukocytes using morphometric data of the nuclei. METHOD: The analyzed images were generated with a laser scanning cytometer. Two free programs were used for image analysis and statistical evaluation: Cellprofiler and Tanagra respectively. A sample of leukocytes with 200 sets of images (DAPI, CD45 and CD14) was analyzed. Using feature selection, the 20 best parameters were chosen to conduct cross-validation. RESULTS: The morphometric data identified the subpopulations of the analyzed leukocytes with a sensitivity and specificity of 0.95 per sample. CONCLUSION: The present study is the first that identifies subpopulations of leukocytes by nuclear morphology.

Triterpenes from the Protium heptaphyllum resin - chemical composition and cytotoxicity

Protium heptaphyllum (Aubl) Marchand, Burseraceae, is popularly used as an analgesic and anti-inflammatory agent. However, the cellular mechanism of action remains unknown. This study aims to evaluate the chemical composition of P. heptaphyllum resin and cytotoxicity on a breast cancer cell line (MCF-7). The chemical composition of the resin was determined by Gas Chromatography coupled to a Mass Spectrometer. The cytotoxicity was evaluated using an MTT assay. Annexin V-FITC, caspase-3, Angiotensin Converting Enzyme activity and Tumor Necrosis Factor alpha (TNF- α) assays were performed to evaluate apoptosis and inflammatory events. The resin consisted of triterpenes, such as α- and β-amyrin. Cytotoxicity was only observed in fractions enriched with α- and β-amyrin. The resin and fractions elicited antiproliferative activity, increased activity of caspase-3 and ACE, and a decrease in the TNF-α level. Altogether, the resin and fractions enriched with α- and β-amyrin promoted cytotoxicity and apoptosis.