Ketone Body Metabolism is Not Required for Improvement of Heart Failure by Ketogenic Diet in Mice.

Failing hearts increasingly metabolize ketone bodies, and enhancing ketosis improves heart failure (HF) remodeling. Circulating ketones are elevated by fasting/starvation, which is mimicked with a high-fat, low-carbohydrate "ketogenic diet" (KD). While speculated that KD improves HF through increased ketone oxidation, some evidence suggests KD paradoxically downregulates cardiac ketone oxidation despite increased ketone delivery.

Metabolic Drivers and Rescuers of Heart Failure.

Cardiac hypertrophy and heart failure involve a number of metabolic alterations. Human genetic mutations and murine genetic deficiency models of metabolic enzymes or transporters largely suggest that these alterations in metabolism are maladaptive and contribute to the cardiac remodeling and dysfunction. Here, we discuss insights into metabolic alterations identified in cardiac hypertrophy and failure, as well as dietary and pharmacologic therapies that counteract these metabolic alterations and have been shown to significantly improve heart failure.

Kinin B1 receptor modulates mitochondrial activity responsivity in fasting and voluntary exercise.

Unlabelled: The Kallikrein-Kinin System (KKS) plays an important role in energy metabolism. We have previously described the importance of the kinin B1 receptor (B1R) in metabolism regulation. Considering that the liver manages the different energy demands of different body tissues, we combined two stressful conditions - fasting and voluntary exercise - to address how B1R may affect liver metabolism, focusing on mitochondrial function.

Bothrops leucurus venom induces acute hypotension in rats by means of its phospholipase A (blD-PLA).

Cardiovascular effects induced by snake venoms, in spite of having a crucial role in the outcome of the envenomation, have been less studied than other toxic activities displayed by these venoms. In this study we evaluated acute cardiovascular responses to Bothrops leucurus venom - Bl-V - both in vivo, in anesthetized rats, and in vitro, in isolated rat mesenteric resistance arteries. Bl-V (10-100 μg protein/kg) caused dose-dependent hypotension, followed by gradual recovery (2-20 min) to basal levels, and induced dose-dependent (1-20 μg/mL) vasodilation in pre-contracted arteries, what was more pronounced when the endothelium remained intact.

Antioxidant effect of sildenafil: Potential hepatoprotection via differential expression of mitochondrial proteins in apolipoprotein E knockout mice.

Background: High plasma cholesterol levels are able to trigger several pathophysiological events, including inflammation, cell damage and especially oxidative stress. Previously, studies have shown that sildenafil exhibited antioxidant effects in several experimental models. Here we evaluate the role of sildenafil in liver redox equilibrium of apolipoprotein E knockout (apoE-KO) mice.

Combined proteomic and functional analysis reveals rich sources of protein diversity in skin mucus and venom from the Scorpaena plumieri fish.

Unlabelled: The biological activities observed upon envenomation by Scorpaena plumieri could be linked to both the venom and the skin mucus. Through a proteomic/functional approach we analyzed protein composition and biological activities of the venom and skin mucus. We identified 885 proteins: 722 in the Venomous Apparatus extracts (Sp-VAe) and 391 in the Skin Mucus extract (Sp-SMe), with 494 found exclusively in Sp-VAe, being named S.

Advances in the characterization of the Scorpaena plumieri cytolytic toxin (Sp-CTx).

Proteins that account for the hemolytic activity found in scorpaeniform fish venoms are responsible for the majority of the effects observed upon envenomation, for instance, neurotoxic, cardiotoxic and inflammatory effects. These multifunctional toxins, described as protein lethal factors and referred to as cytolysins, are known to be extremely labile molecules. In the present work, we endeavored to overcome this constraint by determining optimal storage conditions for Sp-CTx, the major bioactive component from the scorpionfish Scorpaena plumieri venom.

A review on the fish venom and its bioactive compounds.

The most poisonous fish species found along the Brazilian coast is the spotted scorpionfish . Though hardly ever life-threatening to humans, envenomation by can be quite hazardous, provoking extreme pain and imposing significant socioeconomic costs, as the victims may require days to weeks to recover from their injuries. In this review we will walk the reader through the biological features that distinguish this species as well as the current epidemiological knowledge related to the envenomation and its consequences.

Cardiovascular effects of Sp-CTx, a cytolysin from the scorpionfish (Scorpaena plumieri) venom.

Fish venom cytolysins are multifunctional proteins that in addition to their cytolytic/hemolytic effects display neurotoxic, cardiotoxic and inflammatory activities, being described as "protein lethal factors". A pore-forming cytolysin called Sp-CTx (Scorpaena plumieriCytolytic Toxin) has been recently purified from the venom of the scorpionfish Scorpaena plumieri. It is a glycoprotein with dimeric constitution, comprising subunits of approximately 65 kDa.

Reactive oxygen species contribute to dysfunction of bone marrow hematopoietic stem cells in aged C57BL/6 J mice.

Background: Stem cells of intensely regenerative tissues are susceptible to cellular damage. Although the response to this process in hematopoietic stem cells (HSCs) is crucial, the mechanisms by which hematopoietic homeostasis is sustained are not completely understood. Aging increases reactive oxygen species (ROS) levels and inflammation, which contribute to increased proliferation, senescence and/or apoptosis, leading to self-renewal premature exhaustion.

Local inflammatory response induced by scorpionfish Scorpaena plumieri venom in mice.

The Scorpaena plumieri fish venom induces a severe pain and edema, observed both clinically and experimentally. In order to understand more about the envenomation syndrome, the present study characterized experimentally the local acute inflammatory response induced by S. plumieri venom (SpV) in a mouse model of tissue injury.

Stonefish antivenom neutralises the inflammatory and cardiovascular effects induced by scorpionfish Scorpaena plumieri venom.

Venomous fish are often involved in human accidents and symptoms of envenomation include local (intense pain and swelling) and systemic effects (cardiovascular and neurological disorders). However the only commercially available antivenom is against the Indo-Pacific stonefish Synanceja trachynisStonefish Antivenom (SFAV). The aim of the present study was to evaluate the potential of SFAV in neutralising the in vivo effects of some toxic activities of scorpionfish Scorpaena plumieri venom (SpV), and the in vitro immuno cross-reactivity.