title: Effect of maternal restraint stress on fetal development of ICR mice.
abstract: The present study was conducted to elucidate the susceptibility of embryos and fetuses at different gestational stages to the maternal stress in mice. Groups of pregnant ICR mice were subjected to daily 12-h restraint stress, taped in the supine position on a plastic board, on gestational days (GD) 1-4, 5-8, 9-12 and 13-16, respectively. Caesarean sections were performed on gestational day 18, and the fetuses were weighed and examined for morphological defects. During the daily restraint for 4 days, the maternal body weights markedly decreased. Although the body weights recovered gradually after termination of the stress, the recovery was not full until the final stage of pregnancy. Interestingly, restraint stress caused growth retardation of the fetuses, leading to a significant decrease in their body weights, and increased early and late resorptions of embryos and fetuses according to the stress periods. Although the preceding (GD1-4) and concurrent (GD5-8) stresses did not affect embryonic implantation, restraint stress on GD9-12 caused cleft palate. Whereas vertebral abnormalities, mainly bipartite ossification, were observed only in animals stressed on GD5-8, abnormalities of sternebrae, exhibiting asymmetric or bipartite ossification, were enhanced by the stress at all of the gestational stages. On the other hand, the incidence of other malformations including renal malposition and costal abnormalities was not increased by stress at any of the 4 stages. Taken together, the results suggest that intensive restraint stress influences the maternal body weight resulting in growth retardation and increased mortality of embryos and fetuses, in addition to gestational stage-specific ventricular dilatation, cleft palate and sternal abnormalities.
authors.affiliation: College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Korea.
authors.forename: Yea Eun
authors.initials: YE
authors.lastname: Lee
authors.forename: Sang Kuk
authors.initials: SK
authors.lastname: Byun
authors.forename: Sunhee
authors.initials: S
authors.lastname: Shin
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Jang
authors.forename: Byong-il
authors.initials: BI
authors.lastname: Choi
authors.forename: Dongsun
authors.initials: D
authors.lastname: Park
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Jeon
authors.forename: Sang-Seop
authors.initials: SS
authors.lastname: Nahm
authors.forename: Jong-Koo
authors.initials: JK
authors.lastname: Kang
authors.forename: Seock-Yeon
authors.initials: SY
authors.lastname: Hwang
authors.forename: Jong-Choon
authors.initials: JC
authors.lastname: Kim
authors.forename: Yun-Bae
authors.initials: YB
authors.lastname: Kim
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D002972:Cleft Palate / Q000209:etiology / Q000662:veterinary; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D005317:Fetal Growth Retardation / Q000662:veterinary; D005865:Gestational Age; D051379:Mice; D008813:Mice, Inbred ICR / Q000502:physiology*; D011247:Pregnancy; D012149:Restraint, Physical / Q000502:physiology*; D012376:Rodent Diseases; D013131:Spine / Q000002:abnormalities