Effect of a single bout of high intensity exercise on lower respiratory tract contamination in the horse

1997 ◽  
Vol 75 (4) ◽  
pp. 293-295 ◽  
Author(s):  
SL RAIDAL ◽  
DN LOVE ◽  
GD BAILEY
2021 ◽  
Vol 12 ◽  
Author(s):  
Jonghyuk Park ◽  
Jimmy Kim ◽  
Toshio Mikami

Regular exercise training induces mitochondrial biogenesis in the brain via activation of peroxisome proliferator-activated receptor gamma-coactivator 1α (PGC-1α). However, it remains unclear whether a single bout of exercise would increase mitochondrial biogenesis in the brain. Therefore, we first investigated whether mitochondrial biogenesis in the hippocampus is affected by a single bout of exercise in mice. A single bout of high-intensity exercise, but not low- or moderate-intensity, increased hippocampal PGC-1α mRNA and mitochondrial DNA (mtDNA) copy number at 12 and 48h. These results depended on exercise intensity, and blood lactate levels observed immediately after exercise. As lactate induces mitochondrial biogenesis in the brain, we examined the effects of acute lactate administration on blood and hippocampal extracellular lactate concentration by in vivo microdialysis. Intraperitoneal (I.P.) lactate injection increased hippocampal extracellular lactate concentration to the same as blood lactate level, promoting PGC-1α mRNA expression in the hippocampus. However, this was suppressed by administering UK5099, a lactate transporter inhibitor, before lactate injection. I.P. UK5099 administration did not affect running performance and blood lactate concentration immediately after exercise but attenuated exercise-induced hippocampal PGC-1α mRNA and mtDNA copy number. In addition, hippocampal monocarboxylate transporters (MCT)1, MCT2, and brain-derived neurotrophic factor (BDNF) mRNA expression, except MCT4, also increased after high-intensity exercise, which was abolished by UK5099 administration. Further, injection of 1,4-dideoxy-1,4-imino-D-arabinitol (glycogen phosphorylase inhibitor) into the hippocampus before high-intensity exercise suppressed glycogen consumption during exercise, but hippocampal lactate, PGC-1α, MCT1, and MCT2 mRNA concentrations were not altered after exercise. These results indicate that the increased blood lactate released from skeletal muscle may induce hippocampal mitochondrial biogenesis and BDNF expression by inducing MCT expression in mice, especially during short-term high-intensity exercise. Thus, a single bout of exercise above the lactate threshold could provide an effective strategy for increasing mitochondrial biogenesis in the hippocampus.


2018 ◽  
Vol 1 (96) ◽  
Author(s):  
Lina Kreivėnaitė ◽  
Vytautas Streckis ◽  
Sandra Raizgytė ◽  
Asta Lileikienė

Background. There is evidence of physical exercise effect on the adolescents’ balance and strength; however it is not known how aforementioned variables respond to physical exercise with different loads and intensities. Therefore, the aim of the study was to assess the impact of single bout of physical exercise of different intensity on adolescents’ body balance and muscular strength.Methods. Thirty healthy, physically active 11–13-year-old adolescents were randomly allocated to one of the two groups. Both groups performed single bout of physical exercise of high- or low-intensity climbing up and down-stairs. Postural sway and maximum voluntary contractions (MVC) were assessed before and after physical exercise. Results. No statistically significant impact of low or high intensity exercise was found at adolescents’ MVC. High intensity exercise influenced bigger postural sway with eyes closed compared to eyes open ( p < .05). After high-intensity exercise there was a significantly greater postural sway with eyes closed than with eyes open (p < .05). Conclusions. High and low intensity physical exercise had no impact on the adolescents’ maximum voluntary contraction, whereas high intensity exercise deteriorated body balance with eyes closed.Keywords:  adolescence, physical exercise, MVC, balance


2004 ◽  
Vol 558 (1) ◽  
pp. 333-340 ◽  
Author(s):  
Regina M. Crameri ◽  
Henning Langberg ◽  
Peter Magnusson ◽  
Charlotte H. Jensen ◽  
Henrik Daa Schrøder ◽  
...  

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