title: Pre- and post-implantation losses of embryos in aging female IVCS mice.
abstract: Mated female mice of the IVCS strain, aged 90 (control group), 180, 210, 240, 270, 300, 330, 360 and 420 days old, were studied for pre- and post-implantation loss of embryos. The percentage of pre-implantation loss in mice aged 90 to 210 days was 1.7/11.8 (14.4%) to 2.7/11.7 (23.1%). In mice aged 240 to 300 days it increased significantly as compared to the controls (46.5-90.2% versus 14.4%). It reached 100% in 300-days-old mice. The post-implantation loss of embryos and/or fetuses in mice aged 90 to 240 days was 1.0/10.2 (9.8%) to 2.5/9.0 (27.8%). In mice aged 270 to 300 days it increased significantly compared to the controls (100% versus 9.8%). The decrease in reproductive activity appeared first in a decrease in litter size, followed by a decrease in the number of blastocyst and implantation sites, and finally by anovulation during the process of aging in IVCS mice.
authors.affiliation: Department of Laboratory Animal Science, Veterinary Medical Teaching Hospital, Tokyo, Japan.
authors.forename: B
authors.initials: B
authors.lastname: Tappa
authors.forename: H
authors.initials: H
authors.lastname: Amao
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: T R
authors.initials: TR
authors.lastname: Saito
authors.forename: M
authors.initials: M
authors.lastname: Sugiyama
authors.forename: A
authors.initials: A
authors.lastname: Ogasa
authors.forename: K W
authors.initials: KW
authors.lastname: Takahashi
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D002452:Cell Count; D010064:Embryo Implantation / Q000502:physiology*; D005260:Female; D005306:Fertilization; D051379:Mice; D008815:Mice, Inbred Strains / Q000235:genetics; D010060:Ovulation / Q000502:physiology; D013997:Time Factors