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Expression of hyperoxic bradycardia during hyperbaric exposure in rats prenatally exposed to hypoxia (1150.3)
Author(s) -
Rozloznik Miroslav,
Molcan Lubos,
Svitok Pavel,
Balestra Costantino,
Zeman Michal
Publication year - 2014
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.28.1_supplement.1150.3
Subject(s) - hyperoxia , bradycardia , hypoxia (environmental) , anesthesia , endocrinology , medicine , vasoconstriction , heart rate , chemistry , blood pressure , lung , oxygen , organic chemistry
Intermittent prenatal exposure to hypoxia is associated with postnatal alteration in cardiac and endothelial functions. Hyperoxic exposure has significant effects on the cardiovascular system including bradycardia, vasoconstriction and endothelial dysfunction. The impact of intermittent prenatal hypoxia on cardiac rhythm control during mild hyperoxic conditions is unclear. Thus, expression of hyperoxic bradycardia during normobaric and hyperbaric hyperoxia was investigated telemetrically (PA‐C40, Data Sciences Int) in rats prenatally exposed to hypoxia. Six male Wistar rats prenatally exposed to 10% hypoxia between gestation day 19‐21 (H) and 5 control (C) Wistar rats were exposed for 30 minutes to mild hyperbaric hyperoxia (ppO2 63 kPa, pabs 300 kPa and ppO2 108kPa, pabs 300 kPa) and normobaric hyperoxia (ppO2 67 kPA, pabs 100 kPa). Hyperoxic exposure immediately triggered a bradycardic response in all animals. The bradycardic response was significantly more pronounced (p<0.05) during the hyperbaric exposure to ppO2 108kPa in H rats compared to C rats. Ambient pressure change significantly alternated baroreflex sensitivity (p<0.01) during ppO2 63 kPa exposure in H rats. We conclude that hyperbaric exposure to mild hyperoxia indicates a developmental alteration in cardiac rhythm control in rats prenatally exposed to hypoxia and represents a perspective model to study cardiac rhythm alterations. Grant Funding Source : Supported by grants VEGA 1/0686/12, 2/0107/12 and NOREG and FP7‐PEOPLE‐2010‐ITN