Effects of monocrotaline on energy metabolism in the rat liver

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Histochemical study of muscle fiber types in Synbranchus marmoratus Bloch, 1795

The myotomal muscle of Synbranchus marmoratus was investigated using histochemical and immunohistochemical reactions. This musculature is composed of a superficial red compartment, uniformly distributed around the trunk circumferentially and also in the lateral line. The red compartment fibers are small in diameter and have an oxidative metabolism, a high rate of glycogen and a negative reaction to alkaline and acid myofibrillar ATPase (mATPase). The white muscle forms the bulk of the muscle mass. Its fibers are large in diameter and have a glycolytic metabolism, a negative reaction to glycogen, a strong reaction to alkaline mATPase and a negative reaction to acid mATPase. Between these two compartments there is an intermediate layer of fibers presenting a mosaic metabolism pattern with a high rate of glycogen. These fibers stained moderately for alkaline and acid m-ATPase. Several clusters of red muscles were observed inside the white muscle. Each cluster is composed of three fiber types, with a predominance of red and intermediate fibers. Reactivity to anti-MHC BA-D5 was positive only in the intermediate fibers. Reactivity to anti-MHC SC-71 was negative in all fiber types.

Toxic mechanism of cadmium exposure on cardiac tissue

The presence of toxic substances in the workplace environment requires systematic evaluation of exposure and health status in exposed subjects. Cadmium is a highly toxic element found in water. Although free mediated cellular damage and reactive oxygen species (ROS), had been theorized as contributing to the cadmium mechanism of toxicity, and recent investigations have established that free radicals may be important contributors to cardiac dysfunction, there is little information on the effect of cadmium exposure on markers of oxidative stress in cardiac tissue. Cadmium exposure (Cd2+ - 100 mg/1-from CdCl2) in drinking water, during 15 days, significantly increased lipoperoxide and decreased the activities of superoxide dismutase and glutathione peroxidase. No alterations were observed in catalase activity in heart of rats with cadmium exposure. We also observed decreased glycogen and glucose concentration and increased total lipid content in cardiac tissue of rats with cadmium exposure. The decreased activities of alanine transaminase and aspartate transaminase reflected decreased metabolic protein degradation, and increased lactate dehydrogenase activity was related with increases in capacity of glycolysis. Since the metabolic pathways were altered by cadmium exposure, we can conclude that Cd2+ exposure induced ROS and initiate some series of events that occur in the heart and resulted in metabolic pathways alterations.

Localization of total proteins and lactate dehydrogenase in hamster epididymis

The concentration of total protein measured by photocolorimetric methodology and reported as units per 100 mg of tissue decreased from the initial segment to the cauda epididymidis of the Golden hamster, being significant the numeric difference observed between these two regions. This observation was related with an increased synthesis and secretion of proteins to the lumen in proximal segments of the epididymidis duct, mainly in initial segment, as proposed for other rodents. LDH activity was higher in initial segment and distal cauda than in the caput and corpus epididymidis, although no significant differences in mean values had been observed. The high LDH activity observed in initial segment and cauda epididymidis of hamster had been related to an expressive epithelium metabolic activity presented in these regions. This metabolic activity help to guarantee the survival of spermatozoa stored in cauda epididymidis. Furthermore, lower LDH activity noted in the caput and corpus epididymidis might be related with a progressive reduction of glycolysis in initial maturation step of spermatozoa mainly verified in corpus epididymidis. © 2007 Sociedad Chilena de Anatomía.

Energy Metabolism in Cardiac Remodeling and Heart Failure

Fatty acids are the main substrates used by mitochondria to provide myocardial energy under normal conditions. During heart remodeling, however, the fuel preference switches to glucose. In the earlier stages of cardiac remodeling, changes in energy metabolism are considered crucial to protect the heart from irreversible damage. Furthermore, low fatty acid oxidation and the stimulus for glycolytic pathway lead to lipotoxicity, acidosis, and low adenosine triphosphate production. While myocardial function is directly associated with energy metabolism, the metabolic pathways could be potential targets for therapy in heart failure. © 2013 by Lippincott Williams & Wilkins.

Detecting Loci under Recent Positive Selection in Dairy and Beef Cattle by Combining Different Genome-Wide Scan Methods

As the methodologies available for the detection of positive selection from genomic data vary in terms of assumptions and execution, weak correlations are expected among them. However, if there is any given signal that is consistently supported across different methodologies, it is strong evidence that the locus has been under past selection. In this paper, a straightforward frequentist approach based on the Stouffer Method to combine P-values across different tests for evidence of recent positive selection in common variations, as well as strategies for extracting biological information from the detected signals, were described and applied to high density single nucleotide polymorphism (SNP) data generated from dairy and beef cattle (taurine and indicine). The ancestral Bovinae allele state of over 440,000 SNP is also reported. Using this combination of methods, highly significant (P<3.17×10-7) population-specific sweeps pointing out to candidate genes and pathways that may be involved in beef and dairy production were identified. The most significant signal was found in the Cornichon homolog 3 gene (CNIH3) in Brown Swiss (P = 3.82×10-12), and may be involved in the regulation of pre-ovulatory luteinizing hormone surge. Other putative pathways under selection are the glucolysis/gluconeogenesis, transcription machinery and chemokine/cytokine activity in Angus; calpain-calpastatin system and ribosome biogenesis in Brown Swiss; and gangliosides deposition in milk fat globules in Gyr. The composite method, combined with the strategies applied to retrieve functional information, may be a useful tool for surveying genome-wide selective sweeps and providing insights in to the source of selection.

Glicerol-3-Fosfato oxidase em levedura de panificação

Pós-graduação em Alimentos e Nutrição - FCFAR

Avaliação da etapa inicial do sinal insulínico em tecido muscular e hepático de ratos tratados cronicamente com NaF

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos decorrentes da ingestão do fluoreto na sensibilidade à insulina e transdução do sinal insulínico

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oxidação da hemoglobina como modelo de estudo do sistema de óxido-redução eritrocitário: interação entre nitrito de sódio, azul de metileno e cistamina

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Avaliação da via inibitória do sinal insulínico em ratos tratados cronicamente com fluoreto de sódio

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos do fator de crescimento dos fibrobalstos 8 (FGF8) durante a maturação in vitro do complexo cumulus-oócito bovino

Pós-graduação em Ciências Biológicas (Farmacologia) - IBB

Glycosomal Targets for Anti-Trypanosomatid Drug Discovery

Glycosomes are peroxisome-related organelles found in all kinetoplastid protists, including the human pathogenic species of the family Trypanosomatidae: Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. Glycosomes are unique in containing the majority of the glycolytic/gluconeogenic enzymes, but they also possess enzymes of several other important catabolic and anabolic pathways. The different metabolic processes are connected by shared co-factors and some metabolic intermediates, and their relative importance differs between the parasites or their distinct life-cycle stages, dependent on the environmental conditions encountered. By genetic or chemical means, a variety of glycosomal enzymes participating in different processes have been validated as drug targets. For several of these enzymes, as well as others that are likely crucial for proliferation, viability or virulence of the parasites, inhibitors have been obtained by different approaches such as compound libraries screening or design and synthesis. The efficacy and selectivity of some initially obtained inhibitors of parasite enzymes were further optimized by structure-activity relationship analysis, using available protein crystal structures. Several of the inhibitors cause growth inhibition of the clinically relevant stages of one or more parasitic trypanosomatid species and in some cases exert therapeutic effects in infected animals. The integrity of glycosomes and proper compartmentalization of at least several matrix enzymes is also crucial for the viability of the parasites. Therefore, proteins involved in the assembly of the organelles and transmembrane passage of substrates and products of glycosomal metabolism offer also promise as drug targets. Natural products with trypanocidal activity by affecting glycosomal integrity have been reported.

Influência da dieta hiperlipídica ricas em ácidos graxos saturados sobre o metabolismo, estrutura e função cardíaca de ratos com estenose aórtica supravalvar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Obesity Preserves Myocardial Function During Blockade of the Glycolytic Pathway

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)