Population dynamics of arterial cells. XIV. Evidence for no significant G2 arrest of intimal and medial cells in young nonatherosclerotic swine.
In an earlier study of swine results from analysis of tritiated thymidine data by an "ancestor table" method suggested a substantial arrest of arterial cells in the G2 phase of the cell cycle. A later study with a cytofluorometric method gave contradictory results with no evidence for significant G2 arrest. On reexamination of the earlier data with the ancestor table method in the light of current knowledge, it was found that the fact that nuclei in the S and G2 phases prior to division are larger than those in G1 after division had not been taken into account. The main purpose of the current study was to find out whether the evidence for G2 arrest would entirely disappear if adjustments were made for differences in nuclear sizes before and after division. A baseline group sacrificed 2 hr after tritiated thymidine injection and two experimental groups (one fed hyperlipidemic diet and the other given cholesterol-free mash) sacrificed 47 hr after injection were studied. Using the ancestor table method it was found that virtually all labeled arterial cells divided in both groups; thus there is no evidence for G2 arrest. The data was also analyzed with a form of the "mean grain count halving" method and this also showed all labeled cells dividing.
D000818:Animals; D001011:Aorta / Q000166:cytology*; D002455:Cell Division; D002467:Cell Nucleus / Q000648:ultrastructure; D002784:Cholesterol / Q000097:blood; D004261:DNA Replication; D007399:Interphase; D007700:Kinetics; D008938:Mitosis; D013552:Swine
D002784:Cholesterol