title: Passive mechanical properties of cardiac tissues in heart hypertrophy during pregnancy.
abstract: We evaluated changes in passive mechanical properties in cardiac tissues during rat pregnancy. Left and right ventricular free walls were dissected from hearts of nonpregnant, late-pregnant, and postpartum rats. Mechanical experiments in ventricular strips were done by stretch-release cycles using a step motor. The results show that during pregnancy, there is cardiac hypertrophy associated with (1) an increase in myocyte size, particularly of augmented myocyte length, (2) a decrease in passive tension developed by the myocardial walls, and (3) a decrease in both elastic modulus and hysteresis. All changes observed during rat pregnancy were reversed during postpartum. In conclusion, a heart with less ventricular rigidity could contribute to facilitating the ventricular filling in conditions of a greater circulating volume characteristic of pregnancy.
authors: Departamento de Ciencias Químico-Biológicas, Unidad Regional Sur Campus Navojoa, Universidad de Sonora, Blvd. Lázaro Cárdenas No. 100, Colonia Francisco Villa, 85880, Navojoa, Sonora, Mexico. avirgen@navojoa.uson.mx
authors: Adolfo
authors: A
authors: Virgen-Ortiz
authors: J L
authors: JL
authors: Marin
authors: A
authors: A
authors: Elizalde
authors: E
authors: E
authors: Castro
authors: E
authors: E
authors: Stefani
authors: L
authors: L
authors: Toro
authors: J
authors: J
authors: Muñiz
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D006332:Cardiomegaly / Q000473:pathology* / Q000503:physiopathology*; D004195:Disease Models, Animal; D004548:Elasticity / Q000502:physiology; D005260:Female; D006321:Heart / Q000503:physiopathology*; D009200:Myocardial Contraction / Q000502:physiology; D009206:Myocardium / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000473:pathology; D009929:Organ Size / Q000502:physiology; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000473:pathology* / Q000503:physiopathology*; D011270:Pregnancy, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley