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Perinatal Supplemental Oxygen Alters the Ventilatory and Pulmonary Vascular Responses to Hypoxia in Adult Rats
Author(s) -
Hoover Michael,
Greiner Tyler J,
Rotella Diane,
Vellookunnel Shilpa,
Chandrasekar Shreya,
Bates Melissa
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.841.6
Subject(s) - hypoxic pulmonary vasoconstriction , hypoxia (environmental) , vasoconstriction , hypoxic ventilatory response , medicine , hemodynamics , anesthesia , cardiac output , vascular resistance , cardiology , pulmonary hypertension , blood pressure , respiratory system , oxygen , chemistry , organic chemistry
Ascent to altitude is associated with increased ventilation and pulmonary vasoconstriction. These physiological responses are related in healthy subjects such that a high ventilatory drive is associated with blunted pulmonary vasoconstriction. Adults born prematurely and given supplemental oxygen at birth have a blunted ventilatory response to hypoxia. We hypothesized that the hypoxic ventilatory and pulmonary vasoconstrictor responses would be unrelated following neonatal exposure to supplemental oxygen. To test our hypothesis, we used a well‐established rat model of 80% O 2 (OXY) exposure for 14 days post‐natally, with 21% O 2 exposure as a control (CON). Six‐to‐nine months later, we assessed the ventilatory response to graded hypoxia using barometric plethysmography. We also catheterized the right and left ventricles to evaluate the hemodynamic response to 10 minutes of 12% O 2 (hypoxia). We found that, to our surprise, OXY rats did not demonstrate a depressed ventilatory response to hypoxia. However, these animals experienced increased right ventricular systolic pressure in response to 12% O 2 . This was driven primarily by an increase in cardiac output and not increased vascular resistance. There was no relationship between the hypoxic ventilatory drive and right ventricular pressure. In CON animals, the increase in right ventricular pressure with hypoxia was driven primarily by vasoconstriction and, as expected, there was a relationship between the ventilatory and pressure responses. These data suggest that neonatal supplemental oxygen alters the hemodynamic response to hypoxia, possibly through enhanced sympathetic drive. The relationship between ventilation and pulmonary pressure may not translate to individuals born prematurely. Support or Funding Information The University of Iowa Start‐Up Fund