Validation of Housekeeping Genes in the Brains of Rats Submitted to Chronic Intermittent Hypoxia, a Sleep Apnea Model

Obstructive sleep apnea (OSA) is a syndrome characterized by intermittent nocturnal hypoxia, sleep fragmentation, hypercapnia and respiratory effort, and it has been associated with several complications, such as diabetes, hypertension and obesity. Quantitative real-time PCR has been performed in previous OSA-related studies; however, these studies were not validated using proper reference genes. We have examined the effects of chronic intermittent hypoxia (CIH), which is an experimental model mainly of cardiovascular consequences of OSA, on reference genes, including beta-actin, beta-2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and eukaryotic 18S rRNA, in different areas of the brain. All stability analyses were performed using the geNorm, Normfinder and BestKeeper software programs. With exception of the 18S rRNA, all of the evaluated genes were shown to be stable following CIH exposure. However, gene stability rankings were dependent on the area of the brain that was analyzed and varied according to the software that was used. This study demonstrated that CIH affects various brain structures differently. With the exception of the 18S rRNA, all of the tested genes are suitable for use as housekeeping genes in expression analyses.Associacao Fundo de Incentivo a Pesquisa (AFIP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Psicobiol, UNIFESP, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biociencias, UNIFESP Baixada Santista, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, UNIFESP, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biociencias, UNIFESP Baixada Santista, São Paulo, BrazilFAPESP: 2011/15060-4FAPESP: 2011/16011-6CNPq: 558924/2008-5Web of Scienc

Effect of postnatal intermittent hypoxia on locomotor activity and neuronal development in rats tested in early adulthood

The present study evaluated the effects of postnatal intermittent hypoxia on locomotor activity and neuronal cell survival in early adulthood rats. During a critical period of brain development on postnatal day (PD) 7-11, male rat pups were exposed to intermittent hypoxia and randomly assigned to three experimental groups: (1) intermittent hypoxia, (2) normoxia, and (3) control (unhandled). One and a half months later on PD56, a behavioral test was conducted, and cell survival was estimated in the hilus, dental gyrus, and CA1 and CA3 subfields of the hippocampus, nucleus accumbens shell and core, dorsal and ventral striatum, and prefrontal cortex. Our results showed that intermittent hypoxia produced hyperactivity that correlated well with psychomotor agitation observed in patients with schizophrenia. Moreover, post-hypoxic rats exhibited a reduction of the number of neurons in the hilar region of the hippocampus and dorsal striatum, structures that have been neuropathologically associated with schizophrenia.These findings suggest that intermittent hypoxia can modify the pattern of locomotor activity and selectively affect neurons in rats tested in early adulthood.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Acute cocaine effects in paradoxical sleep deprived male rats

Cocaine is a psychomotor drug known to cause behavioural alterations. This study was conducted to characterize behavioural response to acute cocaine injection (7 mg/kg, ip) in paradoxical sleep deprived (PSD) male rats since sleep deprivation is also associated with several behavioural alterations. Cocaine or vehicle was administered to rats at the end of a 4-day period of sleep deprivation, and in home-cage control animals. Cocaine administration in control and PSD rats induced a significant increase in stereotyped behaviour in relation to saline-injected rats. PSD induced significant but heterogeneous effects in animals by increasing grooming while it had effect neither on stereotyped behaviours, locomotion nor on anxiety-like behaviours but significantly decreased rearing behaviour. PSD potentiates the action of cocaine on stereotyped behaviours suggesting supersensitivity of dopaminergic receptors. Thus, the present study indicated that the behavioural effects of cocaine could be modified by PSD. This in turn may have relevant implications in the cocaine effect in abusers under sleep deprived condition. (C) 2004 Elsevier Inc. All rights reserved.Universidade Federal de São Paulo, Dept Psychobiol, EPM, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, EPM, São Paulo, SP, BrazilWeb of Scienc

Cocaine administration increases angiotensin I-converting enzyme (ACE) expression and activity in the rat striatum and frontal cortex

Some central effects of cocaine administration seem to be related to angiotensin II (Ang II) or its metabolites. Nonetheless, it is still an open question whether or not the levels of angiotensin I-converting enzyme (ACE), the main Ang II generating enzyme, are modified by cocaine administration. To evaluate the effect of acute and subchronic cocaine administration on ACE activity and mRNA expression, male rats were randomly assigned to saline or cocaine group. Acute and subchronic cocaine administration induced a significant increase in ACE activity and mRNA expression in the frontal cortex and striatum but not in the hippocampus. These results suggest that some of the Ang II related effects of cocaine upon the central nervous system can be mediated by changes on the expression and activity of ACE in the striatum and frontal cortex. Crown Copyright (C) 2011 Published by Elsevier Ireland Ltd. All rights reserved.Associacao Fundo de Incentivo a Pesquisa (AFIP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo UNIFESP, Dept Psicobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Biofis, BR-04039032 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Ciencias Saude, BR-11060001 Santos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Psicobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Biofis, BR-04039032 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Ciencias Saude, BR-11060001 Santos, SP, BrazilFAPESP: 98/14303-3CNPq: 558924/2008-5CNPq: 481104/2004-6Web of Scienc

Consequences of subchronic and chronic exposure to intermittent hypoxia and sleep deprivation on cardiovascular risk factors in rats

Since studies suggest that both hypoxia and sleep fragmentation are related to cardiovascular alterations induced by obstructive sleep apnea, the present study was designed to evaluate the effects of hypoxia, sleep deprivation, and their combination on biochemical blood parameters in rats. in subchrome experiments (4 days), rats were exposed to intermittent hypoxia (IH) during the light period (2 min room air-2 min 10% O-2 for 12 h/day) and/or paradoxical sleep deprivation (PSD, 24 h/day). Consequences of chronic intermittent hypoxia (CIH) exposure were examined after 21 consecutive days of hypoxia protocol from 10:00 to 16:00 followed by a sleep restriction (SR) period of 18 h (16:00-10:00). Rats were randomly assigned to seven treatment groups: (1) control (2) IH (3) PSD (4) IH-PSD (5) SR (6) CIH and (7) CIH-SR. PSD reduced triglycerides and very low-density lipoprotein (VLDL) cholesterol concentrations and increased total cholesterol and high-density lipoprotein (HDL) cholesterol. IH did not alter any of these parameters. the combination of IH-PSD did not modify the values of total cholesterol and HDL compared to control group. in the chronic experiment, the animals exposed to CIH displayed a reduction of Vitamin B-6 and an increase of triglycerides and VLDL. Our findings show a duration-dependent effect of hypoxia on triglycerides. Rats in the SR and CIH-SR groups showed a diminished concentration of triglycerides and VLDL. SR rats showed a reduction in the concentration of homocysteine but the animals in the CIH-SR treatment condition did not display any alterations in this parameter. in this latter group, an augmentation of cysteine concentration was observed. These results suggest that sleep deprivation and hypoxia modify biochemical blood parameters in distinct ways. (C) 2006 Elsevier B.V. All rights reserved.Universidade Federal de São Paulo, Dept Psychobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Hlth Sci, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Hlth Sci, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04024002 São Paulo, BrazilWeb of Scienc

Candidate HKGs in geNorm evaluation.

<p>Ranking of candidate HKGs by geNorm for each brain structure and all structures together as described by the total M-value. Lower M-values indicate more stable genes. A cut-off value of 1.5 was used.</p><p>Candidate HKGs in geNorm evaluation.</p