J Ogasawara

Publications (2)5.96 Total impact

• Article: Effect of exercise training on the density of endothelial cells in the white adipose tissue of rats.

  D Hatano, J Ogasawara, S Endoh, T Sakurai, S Nomura, T Kizaki, H Ohno, T Komabayashi, T Izawa
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  ABSTRACT: We examined the effects of a 9-week exercise training (TR) in Wistar male rats, beginning at 4 weeks of age, on the density of endothelial cells (ECs) in epididymal white adipose tissue (WAT) and the mRNA expression of angiogenic factors in adipose tissue stromal vascular fraction (SVF) cells. The number of ECs and mRNA expressions were assessed by lectin staining and real-time reverse transcriptase-polymerase chain reaction, respectively. Compared with control (CR) rats, TR rats gained weight more slowly and had significantly lower final weight of WAT due to the reduction in the size and the number of adipocytes. TR significantly increased the number of ECs per square millimeter and per adipocyte (1.37- and 1.23-fold, respectively) in WAT. This is probably because the number of adipocytes is fewer while the number of ECs is constant in the WAT of TR rats, because the regression line of TR rats for adipocyte number-dependent EC number was shifted toward the left without significant differences in the slopes between groups. TR also induced the upregulation of mRNA expression of vascular endothelial growth factor (Vegf)-A and Vegf-receptor-2 in SVF cells, thereby retaining a constant number of ECs in the WAT.
  Scandinavian Journal of Medicine and Science in Sports 12/2011; 21(6):e115-21. · 2.87 Impact Factor
• Article: Effects of exercise training on adipogenesis of stromal-vascular fraction cells in rat epididymal white adipose tissue.

  T Sakurai, S Endo, D Hatano, J Ogasawara, T Kizaki, S Oh-ishi, T Izawa, H Ishida, H Ohno
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  ABSTRACT: Previous studies have shown that exercise training reduced white adipose tissue (WAT) mass compared to that in sedentary controls, and that the smaller mass contained fewer adipocytes. However, the effect of exercise training on adipogenesis is not completely clear. Therefore, we re-examined the effect of exercise training on adipocyte numbers in WAT and, if such an effect was found tested the adipogenic responses of stromal-vascular fraction (SVF) cells containing adipose tissue-derived stem cells (ADSC) in epididymal WAT from exercise-trained (TR) rats. Wistar male rats were divided into two groups: control (C) and TR. The TR rats were subjected to exercise on a treadmill for 9 weeks. SVF cells containing ADSC were separated from epididymal WAT by centrifugation. Expression of adipocyte differentiation-related genes and adipogenesis of SVF cells were examined. In SVF cells of TR rats, the expression of peroxisome proliferator-activated receptor γ (PPARγ) and that of PPARγ target lipogenic genes was dramatically downregulated, whereas that of preadipocyte factor-1 gene was significantly upregulated. Lipid accumulation in SVF cells of TR rats after the induction of adipocyte differentiation was significantly suppressed in comparison with that of C rats. Moreover, increased expression of hypoxia-inducible factor-1α (HIF-1α) protein was observed in SVF cells of TR rats. Pre-treatment of YC-1, a potent HIF-1α inhibitor, in SVF cells of TR rats restored adipogenesis. These results suggest that exercise training suppresses the ability of SVF cells to differentiate into adipocytes, and that underlying mechanisms involve the upregulation of HIF-1α expression.
  Acta Physiologica 12/2010; 200(4):325-38. · 3.09 Impact Factor