タイトル無し
スポンサーリンク
概要
- 論文の詳細を見る
Diurnal changes in the labelling index (L. I.) and the mitotic index (M. I.) as well as the generation time of cells in the basal layer of the tongue epithelium of C<SUB>3</SUB>Hf/He mice were observed by using the pulse labelling method with <SUP>3</SUP>H-thymidine injection. Most of the labelling experiments were done at night when high labelling indices were available. The results were as follows: 1) The diuthal changes in L. I. and M. I. were clearly shown with the peak time at 17:00 for L. I. and at 3:00 for M. I. of cells in the basal layer. In the basal layer there was a local difference in the rat of L. I., namely, a high L. I. was obtained in close proximity to the posterior region of the papillae, and a low L. I. in the anterior region. The possibility of the existence of EPU (Potten; 1979) was suggested.<BR>In general, it was assumed that the proliferation activity of basal cells was higher at night than in daytime. 2) The cellular generation time of basal cells was estimated by two different methods.The generation time obtained by PLM analysis, a method developed by Mendelsohn & Takahashi (1972), was estimated to be 33.6 hrs, including 6.1 hr for S, 3.6 hr for G<SUB>2</SUB>+M and 23.9 hr for G<SUB>1</SUB>. This was about 5 hr shorter than that obtained by daytime labelling experiments. However, it was found that the method of Brown & Oliver (1968) was not applicable for the present experimental results, because the NB/NT values did not break down at 0.5 as they did in the case of hamster cheek pouch cells. The reduction of NB/NT kept its linearity to a point less than 0.37. 3) From the results obtainedin the present study, the cellular event that is most closely related to diurnal changes in cell proliferation is the time whee cells leave the basal layer, which was about 8 hrs at night and 14.5 hrs in daytime after labelling. It seems reasonable to assume that most parts of S-cells in the basal layer do not enter the phase of differentiation (upper layer of the epithelium) immediately and directly after cell division. Some regulatory mechanisms may be intervening to control the transition of basal cells to the differentiation phase.
- 歯科基礎医学会の論文
歯科基礎医学会 | 論文
- 口腔レンサ球菌のベータディフェンシン感受性の多様性とその機構の解析
- ココアによる歯周病関連菌に対する抗菌効果
- Candida albicansに対するDefensinの抗菌活性の検討
- 唾液腺腺様嚢胞癌の偽嚢胞腔内の免疫グロブリン
- 破骨細胞が産生するcathepsin KとMMP-9の局在について : 肺癌骨転移モデルを用いた検討