title: Fine structure and origin of interstitial tissue in the ovary of the pregnant rat.
abstract: Interstitial cells of the rat ovary during pregnancy have been studied by electron microscopy. They show the characteristic fine-structural features associated with steroid-secreting cells. The findings have shown the presence of transitional intermediate stages between theca externa cells and interstitial cells, indicating the possible participation of the theca externa in the formation of interstitial cells.
mesh_terms: D000818:Animals; D003238:Connective Tissue / Q000648:ultrastructure; D003239:Connective Tissue Cells; D005260:Female; D009940:Organoids / Q000648:ultrastructure; D010053:Ovary / Q000166:cytology / Q000648:ultrastructure*; D011247:Pregnancy; D011270:Pregnancy, Animal; D051381:Rats; D013799:Theca Cells / Q000648:ultrastructure*