Nitrergic pathways and L-type calcium channel of MnPO influencing cardiovascular homeostasis

The median preoptic nucleus (MnPO) is one of most important site of the lamina terminalis implicated in the regulation of hydro electrolytic and cardiovascular balance. The purpose of this study was to determine the effect of L-Type calcium channel antagonist, nifedipine, on the increase of median arterial blood pressure (MAP) induce by angiotensin II (ANG II) injected into the MnPO. The influence of nitric oxide (NO) on nifedipine antipressor action has also been studied by utilizing N W-nitro-L-arginine methyl ester (L-NAME) (40 μg 0.2 μL -1) a NO synthase inhibitor (NOSI), 7-nitroindazole (7-NIT) (40 μg 0.2 μL -1), a specific neuronal NO synthase inhibitor (nNOSI) and sodium nitroprusside (SNP) (20 μg 0.2 μL -1) a NO donor agent. We have also investigated the central role of losartan and PD123349 (20 nmol 0.2 μL -1), AT 1 and AT 2, respectively (selective non peptide ANG II receptor antagonists), in the pressor effect of ANG II (25 pmol 0.2 μL -1) injected into the MnPO. Male Wistar rats weighting 200-250 g, with cannulae implanted into the MnPO were utilized. Losartan injected into the MnPO, prior to ANG II, blocked the pressor effect of ANGII. PD 123319 only decreased the pressor effect of ANG II. Rats pre-treated with either 50 μg 0.2 μL -1 or 100 μg 0.2 μL -1 of nifedipine, followed by 25 pmol 0.2 μL -1 of ANG II, decreased ANG II-pressor effect. L-NAME potentiated the pressor effect of ANG II. 7-NIT injected prior to ANG II into the MnPO also potentiated the pressor effect of ANGII but with less intensity than that of L-NAME. SNP injected prior to ANG II blocked the pressor effect of ANG II. The potentiation action of L-NAME and 7-NIT on ANG II-pressor effect was blocked by prior injection of nifedipine. The results described in this study provide evidence that calcium channels play important roles in central ANG II-induced pressor effect. The structures containing NO in the brain, such as MnPO, include both endothelial and neuronal cells, which might be responsible for the influence of nifedipine on the pressor effect of ANG II. These data have shown the functional relationship between L-Type calcium channel and a free radical gas NO in the MnPO, on the control of ANG II-induced pressor effect acting in AT 1 and AT 2 receptors.

Antinociceptive and Behavioral Effects of Methadone Alone or in Combination with Detomidine in Conscious Horses

The antinociceptive and behavioral effects of methadone (MET) alone or combined with detomidine (DET) were studied in horses. Intravenous treatments were randomly administered in a two-phase crossover study. In phase 1, six horses were treated with saline (control) or 0.2 or 0.5 mg/kg methadone (MET0.2; MET0.5, respectively). In phase 2, six horses were treated with 0.01 mg/kg DET alone or with DET combined with 0.2 mg/kg MET (DET/MET0.2). Thermal nociceptive threshold (TNT) and electrical nociceptive thresholds (ENT) were recorded by using a heat projection lamp and electrodes placed in the coronary band of the thoracic limbs, respectively. Spontaneous locomotor activity (SLA) was studied by movement sensors in the stall (phase 1). Chin-to-floor distance was assessed in phase 2. In phase 1, the TNT increased significantly for 30 minute after MET0.5 but not after saline or MET0.2. Hyperesthesia and ataxia were observed in 2 of 6 and 6 of 6 horses after MET0.2 and MET0.5, respectively. SLA increased significantly for 120 minutes after MET in a dose-dependent way, but not after placebo. In phase 2, DET and DET/MET0.2 significantly increased the TNT and ENT above baseline for 15 and 30 minutes, respectively; thresholds were significantly higher with DET/MET0.2 than with DET at the same times. Chin-to-floor distance decreased significantly from baseline for 30 minutes, and no excitatory behavior was observed in both treatments. Although the higher dose of MET induced short-acting antinociception, the associated adverse effects may contraindicate its clinical use. The lower dose of MET potentiated DET-induced antinociception without adverse effects, which might be useful under clinical circumstances. © 2013 Elsevier Inc. All rights reserved.

Efeitos da hidratação sobre a modulação autonômica e parâmetros cardiorrespiratórios durante e após exercício físico de longa duração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos antinociceptivos, cardiorrespiratórios e gastrointestinais da detomidina associada ou não à metadona em equinos

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

Análise da influência do calço e do movimento de inclinação lateral da coluna vertebral em indivíduos com escoliose idiopática

Pós-graduação em Ciências da Motricidade - IBRC

Composição bioquímica e hormonal do líquido ammniotico de fetos bovinos oriundos de inseminação artificial(IA), transferência de embriões(TE) e produção in vitro(PIV)

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

Near-infrared nonlinearity of a multicomponent tellurium oxide glass at 800 and 1,064 nm

We report on the nonlinear (NL) optical properties of glassy TeO2-GeO2-K2O-Bi2O3 at lambda = 800 nm and lambda = 1,064 nm. Using the Kerr gate technique with a laser delivering 150 fs pulses at 800 nm, we demonstrated the fast NL response of the samples. The modulus of the NL refractive index, n (2), at 800 nm was similar to 10(-15) cm(2)/W. The Z-scan technique was used to determine n (2) a parts per thousand +10(-15) cm(2)/W, at 1,064 nm with pulses of 17 ps. The two-photon absorption coefficient, alpha (2), was smaller than the minimum that we can measure (< 0.003 cm/GW). The figure of merit n (2)/alpha (2) lambda was calculated and indicates that this glass composition has large potential to be used for all-optical switching.

Effect of Pursed-Lip Breathing in Patients With COPD: Linear and Nonlinear Analysis of Cardiac Autonomic Modulation

Objective: The aim of the present study was to evaluate the effect of pursed-lip breathing (PLB) on cardiac autonomic modulation in individuals with chronic obstructive pulmonary disease (COPD) while at rest. Methods: Thirty-two individuals were allocated to one of two groups: COPD (n = 17; 67.29 +/- 6.87 years of age) and control (n = 15; 63.2 +/- 7.96 years of age). The groups were submitted to a two-stage experimental protocol. The first stage consisted of the characterization of the sample and spirometry. The second stage comprised the analysis of cardiac autonomic modulation through the recording of R-R intervals. This analysis was performed using both nonlinear and linear heart rate variability (HRV). In the statistical analysis, the level of significance was set to 5% (p = 0.05). Results: PLB promoted significant increases in the SD1, SD2, RMSSD and LF (ms(2)) indices as well as an increase in alpha(1) and a reduction in alpha(2) in the COPD group. A greater dispersion of points on the Poincare plots was also observed. The magnitude of the changes produced by PLB differed between groups. Conclusion: PLB led to a loss of fractal correlation properties of heart rate in the direction of linearity in patients with COPD as well as an increase in vagal activity and impact on the spectral analysis. The difference in the magnitude of the changes produced by PLB between groups may be related to the presence of the disease and alterations in the respiration rate.

Fractal scaling exponents of heart rate variability association with linear indices and Poincaré Plot

The literature indicated that the fractal analysis of heart rate variability (HRV) is related to the chaos theory. However, it is not clear if the both short and long-term fractal scaling exponents of HRV are reliable for short period analysis in women. We evaluated the association of the fractal exponents of HRV with the time and frequency domain and geometric indices of HRV. We evaluated 65 healthy women between 18 and 30 years old. HRV was analyzed with a minimal number of 256 RR intervals in the time (SDNN, RMSSD, NN50 and pNN50) and frequency (LF, HF and LF/HF ratio) domains, the geometric index were also analyzed (triangular indexRRtri, triangular interpolation of RR intervals-TINN and Poincaré plot-SD1, SD2 and SD1/SD2) as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). No significant correlation was observed for alpha-2 exponent with all indices. There was significant correlation of the alpha-1 exponent with RMSSD, pNN50, SDNN/RMSSD, LF (nu), HF (nu and ms2 ), LF/HF ratio, SD1 and SD1/SD2 ratio. Our data does not indicate the alpha-2 exponent to be used for 256 RR intervals and we support the alpha-1 exponent to be used for HRV analysis in this condition.

Fractal dynamics of heart rate variability for short term

The fractal analysis of heart rate variability (HRV) has been associated to the chaos theory. We evaluated the association of the fractal exponents of HRV with the time and frequency domain and geometric indices of HRV for short period. HRV was analyzed with a minimal number of 256 RR intervals in the time (SDNN-standard deviation of normal-to-normal R-R intervals, pNN50-percentage of adjacent RR intervals with a difference of duration greater than 50ms and RMSSD-root-mean square of differences between adjacent normal RR intervals in a time interval) and frequency (LF-low frequency, HF-high frequency and LF/HF ratio) domains. The geometric indexes were also analyzed (RRtri-triangular index, TINN-triangular interpolation of RR intervals and Poincaré plot) as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). We observed strong correlation of the alpha-1 exponent with RMSSD, pNN50, SDNN/RMSSD, LF (nu), HF (nu), LF/HF ratio, SD1 and SD1/Sd2 ratio. In conclusion, we suggest that the alpha-1 exponent could be applied for HRV analysis with a minimal number of 256 RR intervals.

Fractal correlation property of heart rate variability in response to the postural change maneuver in healthy women

Background: We evaluated the effects of the PCM on the fractal analysis of the HRV in healthy women Method: We evaluated healthy women between 18 and 30 years old. HRV was analyzed in the time (SDNN, RMSSD, NN50 and pNN50) and frequency (LF, HF and LF/HF ratio) domains as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). HRV was recorded at rest for ten minutes at seated rest and then the women quickly stood up from a seated position in up to three seconds and remained standing for 15 minutes. HRV was recorded at the following time: rest, 0–5 min, 5–10 min and 10–15 min during standing. Results: We observed decrease (p < 0.05) in the time-domain indices of HRV between seated and 10–15 minutes after the volunteer stood up. The LF (ms2) and HF (ms2) indices were also reduced (p < 0.05) at 10–15 minutes after the volunteer stood up compared to seated while the LF (nu) was increased at 5–10 min and 10–15 min (p < 0.05). The short-term alpha-1 exponent was increased (p < 0.05) at all moments investigated compared to seated. Increase in the properties of short-term fractal correlations of heart rate dynamics accompanied by a decrease in the parasympathetic modulation and global HRV was observed in response to the postural change maneuver. Conclusion: We suggest that fractal analysis of HRV is more sensitive than frequency and time-domain analysis of HRV during the postural change maneuver.

Picosecond nonlinearity of GeO2-Bi2O3-PbO-TiO2 glasses at 532 and 1,064 nm

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aeromonas salmonicida induced immune gene expression in Aloe vera fed steelhead trout, Oncorhynchus mykiss (Walbaum)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of dexmedetomidine on pulse pressure variation changes induced by hemorrhage followed by volume replacement in isoflurane-anesthetized dogs

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

Cimetidine Reduces Alveolar Bone Loss in Induced Periodontitis in Rat Molars

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