title: Temporal and topographic changes in DNA synthesis after induced follicular atresia.
abstract: Hamsters were hypophysectomized on the morning of estrus (Day 1) and injected immediately with 30 IU pregnant mare's serum (PMS). This was followed on Day 4 by the injection of an antiserum to PMS (PMS-AS) that initiated follicular atresia (Time zero). From 0 to 72 h after PMS-AS, the animals were injected with [3H]thymidine and killed 4 h later. One ovary was saved for autoradiography and histology; from the other ovary, 5-10 large antral follicles were dissected and pooled, and incorporation into DNA was determined by scintillation counting. DNA synthesis dropped sharply between 12 and 18 h, coinciding with a fall in labeling index of the cumulus oophorus and thecal endothelial cells and a sharp fall in thecal vascularity. In contrast, for the mural granulosa cells bordering on the antral cavity, labeling index dropped sharply between 8 and 12 h when thecal vascularity was still high. The earliest sign of atresia was evident by 4 h in cumulus cells when, paradoxically, DNA synthesis was still high. It took 3 days for atresia of the antral follicles to progress to advanced stages, as evidenced by pseudo-pronuclei in the free floating ovum, further erosion of the mural granulosa, and minimal DNA/follicle. However, the theca still retained its histological integrity and contained no pyknotic cells. Although by 48 h the granulosal compartment was in disarray (DNA/follicle significantly different from earlier values), the egg was still viable, as judged by maximal fluorescence after the addition of fluoroscein diacetate.
authors: Department of Physiology, University of Kansas Medical Center, Kansas City 66103.
authors: G S
authors: GS
authors: Greenwald
mesh_terms: D000818:Animals; D001345:Autoradiography; D002470:Cell Survival; D006224:Cricetinae; D004247:DNA / Q000096:biosynthesis*; D005260:Female; D005496:Follicular Atresia / Q000187:drug effects*; D005498:Follicular Phase; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D008647:Mesocricetus; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D006080:Ovarian Follicle / Q000033:anatomy & histology; D012588:Scintillation Counting; D013799:Theca Cells / Q000166:cytology / Q000378:metabolism; D013997:Time Factors
chemical_list: D006064:Gonadotropins, Equine; D004247:DNA