Effects of Selenium in the Microcirculation of Fructose-Fed Hamsters.

BACKGROUND AND AIMS: Fructose intake is directly related to vascular dysfunction and it is a risk factor for the development of metabolic and cardiovascular diseases, such as obesity, diabetes, and hypertension. Selenium, a component of antioxidant enzymes, improves hyperglycemia and vascular function in diabetic animals. The aim of this study was to evaluate the effects of dietary selenium supplementation on microcirculatory and metabolic parameters of fructose-fed hamsters. METHODS AND RESULTS: Male hamsters (Mesocricetus auratus) had their drinking water substituted or not by 10% fructose solution for 60 days, during which their microcirculatory function was evaluated in the cheek pouch preparation. Blood glucose and serum insulin levels were also tested. Microcirculatory responses to acetylcholine (an endothelium-dependent vasodilator) and to sodium nitroprusside (SNP, an endothelium-independent vasodilator), and macromolecular permeability increase induced by a 30-min ischemia/reperfusion (I/R) procedure, showed that endothelium-dependent and independent vasodilatation was significantly increased in animals that had high selenium supplementation, in both the control and fructose-fed groups. Selenium supplementation protected against plasma leakage induced by I/R in all control and fructose-fed groups. CONCLUSION: Our results indicate that dietary selenium supplementation reduces microvascular dysfunction by increasing endothelial-dependent and independent dilatation and reducing macromolecular permeability increase in fructose-fed animals.

Bone Marrow-Derived Mononuclear Cell Therapy Accelerates Renal Ischemia-Reperfusion Injury Recovery by Modulating Inflammatory, Antioxidant and Apoptotic Related Molecules.

BACKGROUND/AIMS: We investigated the regenerative capacity of intravenous administration of bone marrow-derived mononuclear cells (BMMCs) in a rat model of bilateral renal ischemia/reperfusion (IR) injury and the involvement of inflammatory anti-inflammatory and other biological markers in this process. METHODS: Rats were subjected to 1h bilateral renal pedicle clamping. BMMCs were injected i.v 1h after reperfusion and tracked by 99mTc and GFP+ BMMCs. Twenty-four hours after reperfusion, renal function and histological changes were evaluated. The mRNA (real time PCR) and protein (ELISA and immuno-staining) expression of biological markers were analyzed. RESULTS: Renal function and structure improved after infusion of BMMCs in the IR group (IR-C). Labeled BMMCs were found in the kidneys after therapy. The expression of inflammatory and biological markers (TLR-2, TRL-4, RAGE, IL-17, HMGB-1, KIM-1) were reduced and the expression of anti-inflammatory and antioxidant markers (IL-10, Nrf2, and HO-1) were increased in IR-C animals compared with IR untreated animals (IR-S). The apoptotic index diminished and the proliferation index increased in IR-C compared with IR-S. CONCLUSION: The results contribute to our understanding of the role of different biological players in morphofunctional renal improvement and cytoprotection in a post-ischemic reperfusion kidney injury model subjected to cellular therapy.

Effects of Incretin-Based Therapies on Neuro-Cardiovascular Dynamic Changes Induced by High Fat Diet in Rats.

BACKGROUND AND AIMS: Obesity promotes cardiac and cerebral microcirculatory dysfunction that could be improved by incretin-based therapies. However, the effects of this class of compounds on neuro-cardiovascular system damage induced by high fat diet remain unclear. The aim of this study was to investigate the effects of incretin-based therapies on neuro-cardiovascular dysfunction induced by high fat diet in Wistar rats. METHODS AND RESULTS: We have evaluated fasting glucose levels and insulin resistance, heart rate variability quantified on time and frequency domains, cerebral microcirculation by intravital microscopy, mean arterial blood pressure, ventricular function and mitochondrial swelling. High fat diet worsened biometric and metabolic parameters and promoted deleterious effects on autonomic, myocardial and haemodynamic parameters, decreased capillary diameters and increased functional capillary density in the brain. Biometric and metabolic parameters were better improved by glucagon like peptide-1 (GLP-1) compared with dipeptdyl peptidase-4 (DPP-4) inhibitor. On the other hand, both GLP-1 agonist and DPP-4 inhibitor reversed the deleterious effects of high fat diet on autonomic, myocardial, haemodynamic and cerebral microvascular parameters. GLP-1 agonist and DPP-4 inhibitor therapy also increased mitochondrial permeability transition pore resistance in brain and heart tissues of rats subjected to high fat diet. CONCLUSION: Incretin-based therapies improve deleterious cardiovascular effects induced by high fat diet and may have important contributions on the interplay between neuro-cardiovascular dynamic controls through mitochondrial dysfunction associated to metabolic disorders.