Efferent Pathways in Sodium Overload-Induced Renal Vasodilation in Rats

Hypernatremia stimulates the secretion of oxytocin (OT), but the physiological role of OT remains unclear. the present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280-350 g) were anesthetized with sodium thiopental (40 mg. kg(-1), i.v.). A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP) and renal blood flow (RBF). Renal vascular conductance (RVC) was calculated as the ratio of RBF by MAP. in anesthetized rats (n = 6), OT infusion (0.03 mu g . kg(-1), i.v.) induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR) reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml . kg(-1) b.wt., i.v.) was infused over 60 s. in sham rats (n = 6), hypertonic saline induced renal vasodilation. the OXTR antagonist (AT; atosiban, 40 mu g . kg(-1) . h(-1), i.v.; n = 7) and renal denervation (RX) reduced the renal vasodilation induced by hypernatremia. the combination of atosiban and renal denervation (RX+AT; n = 7) completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively), whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia.Fundacao de Amparo a Pesquisa do Estado de Goias (FAPEG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Goias, Ctr Neurosci & Cardiovasc Physiol, Inst Biol Sci, Dept Physiol Sci, Goiania, Go, BrazilUniv Fed Uberlandia, Fac Phys Educ, Inst Biol Sci, BR-38400 Uberlandia, MG, BrazilUniversidade Federal de São Paulo, Dept Physiol, São Paulo, BrazilUniv Fed Goias, Inst Biol Sci, Mol Biol Lab, Goiania, Go, BrazilUniv Fed Goias, Inst Biol Sci, Dept Biochem & Mol Biol, Goiania, Go, BrazilUniversidade Federal de São Paulo, Dept Physiol, São Paulo, BrazilFundacao de Amparo a Pesquisa do Estado de Goias (FAPEG): 2012/0055431086Fundacao de Amparo a Pesquisa do Estado de Goias (FAPEG): 2009/10267000352CNPq: 477832/2010-5CNPq: 483411/2012-4Web of Scienc

Intake behavior of dairy cattle fed with crambe meal in soybean meal replacement

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.A crescente preocupa??o mundial com o meio ambiente juntamente com a busca por fontes de energia renov?veis coloca o biodiesel no centro das aten??es e interesses. Assim, considerando a alimenta??o animal como elo entre a produ??o de biodiesel e a pecu?ria, o presente trabalho teve como objetivo avaliar o comportamento ingestivo de bovinos leiteiros em consequ?ncia da substitui??o do farelo de soja (FS) pelo farelo de crambe (Crambe abyssinica) (FC). Foram utilizados quatro machos castrados Holand?s x Zebu, fistulados no r?men, com peso vivo m?dio de 664 kg, distribu?dos em delineamento quadrado latino 4 x 4. Os tratamentos consistiram em quatro dietas isoproteicas e isoenerg?ticas, formuladas com rela??o volumoso: concentrado 60:40 com base na mat?ria seca (MS). O volumoso foi composto de silagem de milho (51% MS) e feno de Tifton (49% MS), e o concentrado formulado com n?veis crescentes de substitui??o do farelo de soja pelo farelo de crambe em 0%, 2,8%, 6,4% e 11,0% na MS da dieta. O comportamento ingestivo foi avaliado atrav?s do m?todo direto de avalia??o visual, em intervalos de 10 minutos, durante per?odos de 24 horas. Registrou-se a frequ?ncia de alimenta??o, rumina??o e ?cio e a posi??o do animal (em p? ou em dec?bito). As vari?veis em p? e em dec?bito n?o diferiram entre os tratamentos, assim como os tempos gastos em alimenta??o, rumina??o e ?cio. A substitui??o do farelo de soja por farelo de crambe mostra-se como uma boa alternativa uma vez que n?o alterou o comportamento ingestivo. Contudo, ? importante ressaltar que estudos sobre o aproveitamento de coprodutos gerados na cadeia produtiva do biodiesel s?o bastante incipientes, e investiga??es aprofundadas devem ser feitas com intuito de agregar esses coprodutos aos sistemas de produ??o.ABSTRACT The growing global concern for the environment, along with the search for renewable energy sources puts biodiesel in the spotlight and interests. Thus, considering the feed animal as a link between the production of biodiesel and livestock, this study aimed to evaluate the feeding behavior of dairy cattle as a result of replacement of soybean meal (SBM) by crambe meal (Crambe abyssinica) (FC). Four male Holstein x Zebu were used, fistulated in the rumen, with average live weight of 664 kg, distributed in Latin square design 4 x 4. The treatments consisted of four isoproteic and isocaloric diets formulated with roughage: concentrate 60:40 with based on dry matter (DM). The forage was composed of corn silage (51% DM) and Tifton hay (49% DM), and concentrate formulated with increasing levels of replacement of soybean meal by crambe meal at 0%, 2.8%, 6,4% and 11.0% in the diet DM. The feeding behavior was measured using the direct method of visual evaluation, in 10-minute intervals during a 24 hour period. It was registered the feeding frequency, rumination and idleness and the animal's position (standing or recumbent). The variables standing and recumbent did not differ between treatments, and the time spent in feeding, rumination and idleness (p>0,05). The crambe meal replacement for soybean meal is shown as a good alternative as it does not alter feeding behavior. However, studies on the use of co-products generated in the biodiesel production chain are quite incipient and thorough investigations must be made in order to add these co-products to production systems

A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao

<p>Abstract</p> <p>Background</p> <p>The basidiomycete fungus <it>Moniliophthora perniciosa </it>is the causal agent of Witches' Broom Disease (WBD) in cacao (<it>Theobroma cacao</it>). It is a hemibiotrophic pathogen that colonizes the apoplast of cacao's meristematic tissues as a biotrophic pathogen, switching to a saprotrophic lifestyle during later stages of infection. <it>M. perniciosa</it>, together with the related species <it>M. roreri</it>, are pathogens of aerial parts of the plant, an uncommon characteristic in the order Agaricales. A genome survey (1.9× coverage) of <it>M. perniciosa </it>was analyzed to evaluate the overall gene content of this phytopathogen.</p> <p>Results</p> <p>Genes encoding proteins involved in retrotransposition, reactive oxygen species (ROS) resistance, drug efflux transport and cell wall degradation were identified. The great number of genes encoding cytochrome P450 monooxygenases (1.15% of gene models) indicates that <it>M. perniciosa </it>has a great potential for detoxification, production of toxins and hormones; which may confer a high adaptive ability to the fungus. We have also discovered new genes encoding putative secreted polypeptides rich in cysteine, as well as genes related to methylotrophy and plant hormone biosynthesis (gibberellin and auxin). Analysis of gene families indicated that <it>M. perniciosa </it>have similar amounts of carboxylesterases and repertoires of plant cell wall degrading enzymes as other hemibiotrophic fungi. In addition, an approach for normalization of gene family data using incomplete genome data was developed and applied in <it>M. perniciosa </it>genome survey.</p> <p>Conclusion</p> <p>This genome survey gives an overview of the <it>M. perniciosa </it>genome, and reveals that a significant portion is involved in stress adaptation and plant necrosis, two necessary characteristics for a hemibiotrophic fungus to fulfill its infection cycle. Our analysis provides new evidence revealing potential adaptive traits that may play major roles in the mechanisms of pathogenicity in the <it>M. perniciosa</it>/cacao pathosystem.</p

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

Transcriptomic responses of mixed cultures of ascomycete fungi to lignocellulose using dual RNA-seq reveal inter-species antagonism and limited beneficial effects on CAZyme expression

Gaining new knowledge through fungal monoculture responses to lignocellulose is a widely used approach that can lead to better cocktails for lignocellulose saccharification (the enzymatic release of sugars which are subsequently used to make biofuels). However, responses in lignocellulose mixed cultures are rarely studied in the same detail even though in nature fungi often degrade lignocellulose as mixed communities. Using a dual RNA-seq approach, we describe the first study of the transcriptional responses of wild-type strains of Aspergillus niger, Trichoderma reesei and Penicillium chrysogenum in two and three mixed species shake-flask cultures with wheat straw. Based on quantification of species-specific rRNA, a set of conditions was identified where mixed cultures could be sampled so as to obtain sufficient RNA-seq reads for analysis from each species. The number of differentially-expressed genes varied from a couple of thousand to fewer than one hundred. The proportion of carbohydrate active enzyme (CAZy) encoding transcripts was lower in the majority of the mixed cultures compared to the respective straw monocultures. A small subset of P. chrysogenum CAZy genes showed five to ten-fold significantly increased transcript abundance in a two-species mixed culture with T. reesei. However, a substantial number of T. reesei CAZy transcripts showed reduced abundance in mixed cultures. The highly induced genes in mixed cultures indicated that fungal antagonism was a major part of the mixed cultures. In line with this, secondary metabolite producing gene clusters showed increased transcript abundance in mixed cultures and also mixed cultures with T. reesei led to a decrease in the mycelial biomass of A. niger. Significantly higher monomeric sugar release from straw was only measured using a minority of the mixed culture filtrates and there was no overall improvement. This study demonstrates fungal interaction with changes in transcripts, enzyme activities and biomass in the mixed cultures and whilst there were minor beneficial effects for CAZy transcripts and activities, the competitive interaction between T. reesei and the other fungi was the most prominent feature of this study