NFκB2 Gene as a Novel Candidate that Epigenetically Responds to Interval Walking Training.

Physical fitness has been reported to decrease the risk of lifestyle-related diseases. The present study evaluated genome-wide methylation under the hypothesis that interval walking training (IWT) imparted beneficial effects on health, particularly by epigenetically ameliorating susceptibility to inflammation. We screened DNA from peripheral blood samples via genome-wide microarray for genes whose methylation was affected by IWT, paying special attention to promoter regions, and identified over 40 hyper- or hypo-methylated genes following IWT that were not witnessed in controls. We next selected genes in which the degree of methylation change in the promoter region was correlated with energy consumption following IWT. In this way, we found the NFκB2 gene to have increased methylation in multiple regions of its promoter sequence following participation in an exercise regimen. Next, IWT-induced NFκB2 hyper-methylation was confirmed by a quantitative PyroSequencing assessment of methylation in samples obtained from independent subjects who also underwent IWT. The increase in NFκB2 gene promoter methylation by IWT indicates that this regimen may suppress pro-inflammatory cytokines. Thus, these results provide an additional line of evidence that IWT is advantageous in promoting health from an epigenetic perspective by ameliorating susceptibility to inflammation.

Physical fitness and indices of lifestyle-related diseases before and after interval walking training in middle-aged and older males and females.

HYPOTHESIS: Whether increasing peak aerobic capacity for walking (VO(2peak)) by interval walking training (IWT) is closely linked with decreasing the indices of lifestyle-related diseases (LSDs) in middle-aged and older people were examined. METHODS: For 4 months from April to September 2005 or 2006, 246 males and 580 females (∼65 years) performed IWT consisting of ≥5 sets of fast walking at ≥70% VO(2peak) for 3 min followed by slow walking at ≤40% VO(2peak) for 3 min ≥4 days/week. Before and after IWT, we measured VO(2peak), body mass index (BMI), %body fat, arterial blood pressure, thigh muscle strength and blood parameters. We analysed 198 males and 468 females who had undergone all the measurements both before and after IWT. To examine the hypothesis, we divided the subjects equally into three groups according to their pretraining VO(2peak): low, middle and high groups for each sex. RESULTS: Before training, it was found that thigh muscle strength and blood high-density lipoprotein cholesterol concentration were lower, whereas body weight, BMI, %body fat, arterial blood pressure and blood glucose were higher in the low group than the high group (all, p<0.05). After training, although VO(2peak) and thigh muscle strength increased and body weight, BMI, %body fat, blood pressure and blood glucose concentration decreased in all groups (all, p<0.05), the changes were greatest in the low group for both sexes. CONCLUSION: VO(2peak) at baseline and changes in response to training were closely linked with indices of LSDs.

Plasma lactate concentration and muscle blood flow during dynamic exercise with negative-pressure breathing.

This study assessed the hypothesis that increasing cardiac filling pressure (CFP) would enhance contracting muscle blood flow (MBF) by stretching cardiopulmonary baroreceptors and attenuate the increase in plasma lactate concentration ([Lac(-)](p)) during dynamic exercise. Continuous negative-pressure breathing (CNPB) (-15 cmH(2)O) was used to increase the CFP by accelerating the venous return to the heart. In the first series of experiments, 10 men performed a graded exercise seated on a cycle ergometer with (N1) and without CNPB (C1). The increase in [Lac(-)](p) for N1 was attenuated at 60%, 90%, and 100% of maximal exercise intensity compared with that in C1 (P < 0.001). Also, the increases in mean arterial pressure (MAP) and plasma catecholamine concentrations were attenuated in N1 compared with those in C1 throughout the graded exercise (P < 0.05). However, heart rate and pulse pressure were not significantly influenced by CNPB. Second, we studied the impact of CNPB on forearm MBF during a rhythmic handgrip exercise in 5 of the 10 subjects. Forearm MBF was measured immediately after cessation of the exercise by venous occlusion plethysmography at rest, 30%, 50%, and 70% of maximal work load (WL(max)) with (N2) and without CNPB (C2). Forearm MBF and vascular conductance for both trials increased with the increase in intensity, but forearm skin blood flow measured by laser-Doppler flowmetry remained unchanged. MBF and vascular conductance in N2, however, increased more than in C2 at every intensity (P < 0.01) except for MBF at 70% WL(max), whereas the increase in MAP for N2 was attenuated compared with that in C2 (P < 0.05). Thus augmented active muscle vasodilation occurred in N2 with a lower increase in MAP compared with that in C2. These findings suggest that the stretch of intrathoracic baroreceptors, such as cardiopulmonary mechanoreceptors, by CNPB increased MBF by suppressing sympathetic nerve activity. The attenuation of the increase in [Lac(-)](p) might be caused, at least partially, by the increased MBF.

[Antiallergic effects of mequitazine. 1. In vitro experiments].

The antiallergic effects of 10-(3-quinuclidinylmethyl)phenothiazine (mequitazine) were investigated in vitro. The results obtained were as follows: 1) In the isolated trachea and lung parenchyma of guinea pigs, mequitazine showed a fairly potent antagonistic action against contractions induced by both histamine (Hi) and acetylcholine (ACh). Mequitazine was much less potent in antihistaminic action and slightly more potent in anticholinergic action than ketotifen. The contractions of the preparation by leukotriene (LT) D4 were antagonized by mequitazine, although the potency was moderate, showing an IC50 value of 2.3 x 10(-5) g/ml in the trachea and 5.1 x 10(-5)g/ml in the lung parenchyma. Mequitazine had no effect on the contraction of the trachea by PGF2 alpha, but inhibited that of the lung parenchyma with pA2 = 7.0. 2) Mequitazine (10(-6) g/ml) slightly inhibited the Schultz-Dale reaction of the isolated guinea pig trachea, while ketotifen at the same concentration did not show any effect. 3) The contraction of the isolated guinea pig trachea by Ca2+ influx was slightly inhibited by mequitazine (10(-5) g/ml). 4) Mequitazine competitively inhibited the cyclic AMP-dependent phosphodiesterase activity from the rat lung with a potency of 10 times and 5 times more than those of ketotifen and theophylline, respectively. 5) Mequitazine (10(-6) to 10(-5) M) suppressed both the anaphylactic and phospholipase A2-induced histamine release from the peritoneal cells of rats. 6) Mequitazine (10(-5) g/ml) also inhibited the anaphylactic and Ca ionophore-induced histamine release from the leukocytes of the atopic patients and normal subjects. 7) The anaphylactic releases of histamine, LTB4 and peptide LT from the human lung fragments were dose-dependently inhibited by mequitazine (10(-7) approximately 10(-5) g/ml).