title: What knockout mice can tell us about parturition.
abstract: Many molecules, including steroid and peptide hormones, prostaglandins and cytokines, regulate the preparation, initiation and progression of parturition in mammals. Gene targeting studies show that, in the knockout mice of steroid 5alpha-reductase type 1 gene, prostaglandin F2alpha receptor gene and cytosolic phospholipase A2 gene, parturition was severely disturbed, although live offspring were delivered by Caesarean section. Relaxin gene-disrupted mice also showed protracted labour. However, most knockout mice in which the steroid hormone, prostaglandin, cytokine or peptide hormone (for example, oxytocin, corticotrophin releasing hormone and endothelin) endocrine-paracrine systems are disrupted are inadequate for analysis of the mechanism of parturition because they die before reaching reproductive age or are infertile, or because they reproduce normally. A conditional knockout strategy, for example, using the Cre-LoxP system, should be considered for investigating the biochemical background of parturition to overcome these problems.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Medical School, Suita City, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Ogita
authors.forename: C
authors.initials: C
authors.lastname: Kusui
authors.forename: K
authors.initials: K
authors.lastname: Ohashi
authors.forename: C
authors.initials: C
authors.lastname: Azuma
authors.forename: Y
authors.initials: Y
authors.lastname: Murata
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000235:genetics* / Q000502:physiology; D000818:Animals; D018031:Connexin 43 / Q000235:genetics / Q000502:physiology; D003346:Corticotropin-Releasing Hormone / Q000235:genetics / Q000502:physiology; D016207:Cytokines / Q000235:genetics / Q000502:physiology; D004967:Estrogens / Q000235:genetics / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D007743:Labor, Obstetric / Q000235:genetics* / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D010121:Oxytocin / Q000235:genetics / Q000502:physiology; D010741:Phospholipases A / Q000235:genetics* / Q000502:physiology; D054467:Phospholipases A2; D011247:Pregnancy; D011374:Progesterone / Q000235:genetics / Q000502:physiology; D011982:Receptors, Prostaglandin / Q000235:genetics* / Q000502:physiology; D012065:Relaxin / Q000235:genetics / Q000502:physiology
chemical_list: D018031:Connexin 43; D016207:Cytokines; D004967:Estrogens; D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; D011374:Progesterone; D010121:Oxytocin; D012065:Relaxin; D003346:Corticotropin-Releasing Hormone; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase; D010741:Phospholipases A; D054467:Phospholipases A2