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Prenatal dexamethasone produces altered cardiovascular and autonomic responses to psychological stress
Author(s) -
Polson Jaimie W,
Bisterbosch Heimerich M,
Panahi S Ehsan,
Dampney Roger AL
Publication year - 2012
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.26.1_supplement.lb793
Subject(s) - offspring , glucocorticoid , endocrinology , dexamethasone , medicine , heart rate , baroreflex , gestation , blood pressure , prenatal stress , hemodynamics , gestational age , pregnancy , biology , genetics
Raised glucocorticoid levels during gestation are known to increase the risk of high blood pressure (BP) in the offspring in later life, possibly due to altered autonomic regulation. We compared the cardiovascular responses and spontaneous baroreflex gain (sBRG) changes to 15 min of repeated air puffs in rat offspring following raised gestational glucocorticoid produced by dexamethasone (DEX, 200 μg/kg) administration in the pregnant dam, and controls. At 10 months of age, the offspring were implanted with telemetry probes and BP was recorded in the awake, freely moving rat. BP, heart rate (HR), and sBRG were determined before, during and after rats were subjected to air puff stress. At rest, we found no difference in BP between groups, while HR (control, 315±8 vs DEX, 336±5 bpm, p<0.05) was higher and sBRG (2.03±0.18 vs 1.14±0.05 ms/mmHg, p<0.05) was lower in the DEX group. During air puff stress, BP and HR increased similarly in both groups. sBRG was reduced more in DEX than controls (by 20±5 vs 50±7%, p<0.05). After stress, BP and HR recovered more slowly in DEX rats. At 30 min post stress, a second “delayed” stress response was observed in which BP and HR increased again. The duration of this response was greater in DEX than controls (20±4.9 vs 27±1.2 min, p<0.05). Our results indicate that cardiovascular and sBRG responses to stress are exaggerated following prenatal exposure to DEX.