Effect of Time of Day on Performance, Hormonal and Metabolic Response during a 1000-M Cycling Time Trial

The aim of this study was to determine the effect of time of day on performance, pacing, and hormonal and metabolic responses during a 1000-m cycling time-trial. Nine male, recreational cyclists visited the laboratory four times. During the 1st visit the participants performed an incremental test and during the 2nd visit they performed a 1000-m cycling familiarization trial. On the 3rd and 4th visits, the participants performed a 1000-m TT at either 8 am or 6 pm, in randomized, repeated-measures, crossover design. the time to complete the time trial was lower in the evening than in the morning (88.2 +/- 8.7 versus 94.7 +/- 10.9 s, respectively, p<0.05), but there was no significant different in pacing. However, oxygen uptake and aerobic mechanical power output at 600 and 1000 m tended to be higher in the evening (p<0.07 and 0.09, respectively). There was also a main effect of time of day for insulin, cortisol, and total and free testosterone concentration, which were all higher in the morning (+60%, +26%, +31% and +22%, respectively, p<0.05). the growth hormone, was twofold higher in the evening (p<0.05). the plasma glucose was similar to 11% lower in the morning (p<0.05). Glucagon, norepinephrine, epinephrine and lactate were similar for the morning and evening trials (p<0.05), but the norepinephrine response to the exercise was increased in the morning (+46%, p<0.05), and it was accompanied by a 5-fold increase in the response of glucose. Muscle recruitment, as measured by electromyography, was similar between morning and evening trials (p<0.05). Our findings suggest that performance was improved in the evening, and it was accompanied by an improved hormonal and metabolic milieu.Alagoas Research Foundation (FAPEAL)Univ Fed Alagoas, Sports Sci Res Grp, Maceio, Alagoas, BrazilUniv Fed Pernambuco, CAV, Dept Phys Educ & Sports Sci, Vitoria de Santo Anta, PE, BrazilUniv São Paulo, Sch Phys Educ & Sport, Endurance Performance Res Grp, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilVictoria Univ, Inst Sport Exercise & Act Living, Melbourne, Vic 8001, AustraliaUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilAlagoas Research Foundation (FAPEAL): 20110825-011-0025-0004Web of Scienc

Diabetic Nephropathy Induced by Increased Ace

Population studies have shown an association between diabetic nephropathy (DN) and insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene (ACE in humans, Ace in mice). The aim was to evaluate the modulation of Ace copies number and diabetes mellitus (DM) on renal RAS and correlate it with indicators of kidney function. Increased number of copies of the Ace gene, associated with DM, induces renal dysfunction. The susceptibility to the development of DN in 3 copies of animals is associated with an imbalance in activity of RAS enzymes leading to increased synthesis of Ang II and Ang-(1–7). Increased concentration of renal Ang-(1–7) appears to potentiate the deleterious effects triggered by Ang II on kidney structure and function. Results also show increased bradykinin concentration in 3 copies diabetic group. Taken together, results indicate that the deleterious effects described in 3 copies diabetic group are, at least in part, due to a combination of factors not usually described in the literature. Thus, the data presented here show up innovative and contribute to understanding the complex mechanisms involved in the development of DN, in order to optimize the treatment of patients with this complication

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

The study aimed to associate dysfunctions of renal system with possible alterations in expression and/or ACE activity and in angiotensin levels beside analyzing the losartan and enalapril effects in a model of progressive renal disease

BV UNIFESP: Teses e dissertaçõe

Unreliability of EDTA samples for measuring bioamine neurotransmitter levels in cats. Journal of Feline Medicine and Surgery

Objectives The aim of this study was to assess the reliability of an EDTA-based method for measuring cat blood bioamines. Methods Test 1 involved collecting blood samples from seven university laboratory cats. The samples were transferred to EDTA, heparin and plain tubes to determine concentrations of four bioamines (serotonin, dopamine, epinephrine [adrenaline] and norepinephrine [noradrenaline]). Correlation of measurements performed on EDTA plasma, with those performed on heparinized plasma or serum were assessed by intraclass correlation coefficients (ICCs). In test 2, blood samples from five owned cats were collected and stored in EDTA tubes and divided between duplicate Eppendorf tubes labeled as different cats for blinding purposes and analyzed independently for the same four bioamines as in test 1. Reliability of concentration determination for these duplicates was assessed by ICCs and coefficients of variation (CVs). Results In test 1, there was no significant correlation between the EDTA plasma serotonin and serum serotonin concentrations. There was also no significant correlation between EDTA plasma and heparin plasma concentrations for either epinephrine or norepinephrine. There was a statistically significant but weak correlation between EDTA plasma and heparin plasma dopamine concentrations. In test 2, there was no correlation for repeat-analyzed serotonin and epinephrine concentrations. Although there were statistically significant correlations for dopamine and norepinephrine, CVs for each analyte were in excess of 30%. Conclusions and relevance Before any further attempt is made to measure and report on neurotransmitter concentrations in domestic cats, it is essential that the robustness of the methodology is carefully validated and the data presented

Overexpression of Urinary N-Domain ACE in Chronic Kidney Dysfunction in Wistar Rats

Local activation of the renin-angiotensin system (RAS) has been implicated in the pathogenesis of several renal disorders. in this study we investigated how chronic kidney disease (CKD) modulates RAS components in an experimental model. Male Wistar rats were divided into three groups: sham, nephrectomized, and nephrectomized receiving losartan. Chronic kidney disease animals presented decreased renal N-domain angiotensin-converting enzyme (ACE) activity but overexpression of N-domain ACE in urine. Remnant kidneys presented high angiotensin II levels. Losartan treatment increased urine and tissue ACE activity and tissue levels of angiotensins, mainly angiotensin (1-7), and improved renal and histopathologic parameters. Taken together, the authors' results indicate that pathophysiological changes due to CKD could lead to an increased expression of somatic and N-domain ACE, mainly the 65 kDa isoform, suggesting that this enzyme could be used as a biological urinary marker in CKD.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Sch Med, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Sci & Technol, São Paulo, BrazilCleveland Clin, Lerner Res Inst, Cleveland, OH 44106 USAUniversidade Federal de São Paulo, Sch Med, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Sci & Technol, São Paulo, BrazilFAPESP: 02/02920-5FAPESP: 02/13290-2Web of Scienc

Purification and characterization of angiotensin converting enzyme 2 (ACE2) from murine model of mesangial cell in culture

Angiotensin converting enzyme 2 (ACE2) is a component of the renin-angiotensin system (RAS) which converts Ang II, a potent vasoconstrictor peptide into Ang 1-7, a vasodilator peptide which may act as a negative feedback hormone to the actions of Ang II. the discovery of this enzyme added a new level of complexity to this system. the mesangial cells (MC) have multiple functions in glomerular physiology and pathophysiology and are able to express all components of the RAS. Despite of being localized in these cells, ACE2 has not yet been purified or characterized. in this study ACE2 from mice immortalized MC (IMC) was purified by ion-exchange chromatography. the purified enzyme was identified as a single band around 60-70 kDa on SDS-polyacrylamide gel and by Western blotting using a specific antibody. the optima pH and chloride concentrations were 7.5 and 200 mM, respectively. the N-terminal sequence was homologous with many species ACE2 N-terminal sequences as described in the literature. ACE2 purified from IMC was able to hydrolyze Ang II into Ang 1-7 and the K(m) value for Ang II was determined to be 2.87 +/- 0.76 mu M. in conclusion, we purified and localized, for the first time, ACE2 in MC, which was able to generate Ang 1-7 from Ang II. Ang 1-7 production associated to Ang II degradation by ACE2 may exert a protective effect in the renal hemodynamic. (C) 2011 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Div Nephrol, Dept Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Immunol & Parasitol Div, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Dept Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Immunol & Parasitol Div, BR-04023900 São Paulo, BrazilFAPESP: 05-57543-0Web of Scienc