Yazar "Yigit, A" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Changes in the size distribution of steroidogenic and non-steroidogenic bovine luteal cells during the oestrus cycle
    (Scientific Technical Research Council Turkey, 2001) Yigit, A; Arikan, S
    The aim of this study was to investigate the size distribution of steroidogenic and non-steroidogenic luteal cells throughout the oestrus cycle. Twelve corpora lutea collected from different stages of the oestrus cycle were used. Corpora lutea collected from nonpregnant cows were dissociated into single-cell suspensions by enzyme treatments. Cells were stained for 3 beta -hydroxysteroid dehydrogenase (3 beta -HSD) activity, a marker for steroidogenic cells. The sizes of 3 beta -HSD positive (steroidogenic) and negative cells (nonsteroidogenic) were measured with an ocular micrometer. Very small cells (<10 m) stained negative for 3 beta -HSD activity were presumed to be primarily endothelial cells, fibroblast and blood cells. The other cells were presumed to be luteal cells covering a wide spectrum of size ranging from 10 to 40 mum in diameter. 3 beta -HSD positive cells smaller than 10 mum were not observed, and cells larger than 25 mum were rare. The cells obtained from early and late stages of the luteal phase contained more non-steroidogenic cells than the cells obtained from the mid-luteal phase. However, the cells derived from early luteal stage contained more small cells (10-22 mum) than the cells obtained from the rest of the cycle. There were significant differences (p < 0.001) in both 3-HSD positive and 3 beta -HSD negative cell sizes during the oestrus cycle. This study indicates that the size distributions of both steroidogenic and non-steroidogenic luteal cells change as the age of the corpus luteum increases.
  • [ X ]
    Öğe
    Size distribution of bovine steroidogenic luteal cells during pregnancy
    (Cambridge Univ Press, 2001) Arikan, S; Yigit, A
    This study was designed to investigate the size distribution of bovine steroidogenic luteal cells throughout pregnancy. Corpora lutea collected from three different stages of pregnancy were used. Luteal tissue was dissociated into single-cell suspension by enzyme treatments. Cells were stained for 3 beta -hydroxysteroid dehydrogenase (HSD) activity, a marker for steroidogenic cells. The steroidogenic cells covered a wide spectrum of size ranging from 10 to 60 mum in diameter. There was a significant increase in mean cell diameter (P > 0.05) as pregnancy progressed. Mean diameter of 3 beta -HSD positive cells increased from 17.03 (s.e.1.3) pm in the cot-pus luteum of early pregnancy to 33.38 (s.e. 2.4) mum in the corpus luteum of advanced pregnancy. The ratio of large (> 22 mum in diameter) to small (10 to 22 mum in diameter) luteal cells was 0.32 : 1.0 in the early pregnancy, with the 10 to 22 mum cell size class predominant. However, the ratio of large to small lacteal cells was increased to 6.49 : 1.0 mum as pregnancy advanced and 23 to 42 mum cell sizes become predominant. It is likely that small luteal cells develop into large cells as gestation progresses. Development of pregnancy is associated with an increase in size of steroidogenic luteal cells.