G2 sub-population in mouse liver induced into mitosis by lead acetate.
A single intracardiac dose of lead acetate (40 microgram lead/g body weight) induced a 25-fold increase in mitosis of mouse hepatocytes 5 hr after injection, as determined by autoradiography. The prompt appearance of a mitotic wave and the relatively large number of mitoses suggest that the mitotic cells were derived from a hepatocyte sub-population arrested in the G2 phase. The injection of lead also stimulated a small increase in labeled hepatocytes within 6 hr. Analysis of grain counts gave no evidence for unscheduled DNA synthesis. The incremental labeled cells may have originated from a small fraction of the G1 population that was ready to enter the S phase without the usual pre-synthetic delay.
D000818:Animals; D002453:Cell Cycle; D004247:DNA / Q000096:biosynthesis; D005260:Female; D007700:Kinetics; D007854:Lead / Q000494:pharmacology*; D008099:Liver / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008938:Mitosis; D008940:Mitotic Index
D007854:Lead; D004247:DNA