title: High altitude hypoxia and blood pressure dysregulation in adult chickens.
abstract: Although it is accepted that impaired placental perfusion in complicated pregnancy can slow fetal growth and programme an increased risk of cardiovascular dysfunction at adulthood, the relative contribution of reductions in fetal nutrition and in fetal oxygenation as the triggering stimulus remains unclear. By combining high altitude (HA) with the chick embryo model, we have previously isolated the direct effects of HA hypoxia on embryonic growth and cardiovascular development before hatching. This study isolated the effects of developmental hypoxia on cardiovascular function measured in vivo in conscious adult male and female chickens. Chick embryos were incubated, hatched and raised at sea level (SL, nine males and nine females) or incubated, hatched and raised at HA (seven males and seven females). At 6 months of age, vascular catheters were inserted under general anaesthesia. Five days later, basal blood gas status, basal cardiovascular function and cardiac baroreflex responses were investigated. HA chickens had significantly lower basal arterial PO2 and haemoglobin saturation, and significantly higher haematocrit than SL chickens, independent of the sex of the animal. HA chickens had significantly lower arterial blood pressure than SL chickens, independent of the sex of the animal. Although the gain of the arterial baroreflex was decreased in HA relative to SL male chickens, it was increased in HA relative to SL female chickens. We show that development at HA lowers basal arterial blood pressure and alters baroreflex sensitivity in a sex-dependent manner at adulthood.
authors: 1 Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors: E A
authors: EA
authors: Herrera
authors: 2 Instituto Boliviano de Biología de Altura, Facultad de Medicina, Universidad Mayor de San Andrés, La Paz, Bolivia.
authors: C E
authors: CE
authors: Salinas
authors: 3 National Children's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland.
authors: C E
authors: CE
authors: Blanco
authors: 2 Instituto Boliviano de Biología de Altura, Facultad de Medicina, Universidad Mayor de San Andrés, La Paz, Bolivia.
authors: M
authors: M
authors: Villena
authors: 4 Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
authors: D A
authors: DA
authors: Giussani
mesh_terms: D000532:Altitude Sickness / Q000150:complications / Q000503:physiopathology*; D000818:Animals; D017704:Baroreflex / Q000502:physiology*; D001784:Blood Gas Analysis; D001794:Blood Pressure; D001838:Bolivia; D002319:Cardiovascular System / Q000503:physiopathology*; D002642:Chick Embryo; D005260:Female; D006334:Heart Function Tests; D006400:Hematocrit; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000209:etiology*; D012737:Sex Factors