title: Maternal cardiovascular changes during pregnancy and postpartum in mice.
abstract: Genetically altered mice may provide useful models for exploring cardiovascular regulation during pregnancy and postpartum if changes in mice mimic humans. We found in awake ICR (CD-1) mice at 17.5 days gestation that hematocrit was reduced 18%, and the pressor response to intravenous angiotensin II was reduced ~33%. Arterial pressure in awake mice was 12% lower in early pregnancy (3.5 days) than late pregnancy (17.5 days) and postpartum (3 and 17 days after delivery), whereas heart rate was 10-20% higher in the peripartum period (17.5 days gestation and 3 days postpartum). In late pregnancy, cardiac output under isoflurane anesthesia was 64% higher than in nonpregnant mice, due to a 37% increase in stroke volume and a 17% increase in heart rate. All changes P < 0.05. We conclude that, as in humans, mice exhibit hypotension in early pregnancy, and a blunted pressor response to angiotensin II, a decrease in hematocrit, and a marked increase in cardiac output in late pregnancy.
authors.affiliation: Samuel Lunenfeld Research Institute at Mount Sinai Hospital, Toronto, M5G 1X5, Ontario, Canada.
authors.forename: Alan Y H
authors.initials: AY
authors.lastname: Wong
authors.forename: Shathiyah
authors.initials: S
authors.lastname: Kulandavelu
authors.forename: Kathie J
authors.initials: KJ
authors.lastname: Whiteley
authors.forename: Dawei
authors.initials: D
authors.lastname: Qu
authors.forename: B Lowell
authors.initials: BL
authors.lastname: Langille
authors.forename: S Lee
authors.initials: SL
authors.lastname: Adamson
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002302:Cardiac Output; D002320:Cardiovascular Physiological Phenomena; D005260:Female; D006339:Heart Rate; D006400:Hematocrit; D006439:Hemodynamics / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D012016:Reference Values; D013318:Stroke Volume