Prenatal exposure to dexamethasone in the mouse alters cardiac growth patterns and increases pulse pressure in aged male offspring.
Exposure to synthetic glucocorticoids during development can result in later cardiovascular and renal disease in sheep and rats. Although prenatal glucocorticoid exposure is associated with impaired renal development, less is known about effects on the developing heart. This study aimed to examine the effects of a short-term exposure to dexamethasone (60 hours from embryonic day 12.5) on the developing mouse heart, and cardiovascular function in adult male offspring. Dexamethasone (DEX) exposed fetuses were growth restricted compared to saline treated controls (SAL) at E14.5, but there was no difference between groups at E17.5. Heart weights of the DEX fetuses also tended to be smaller at E14.5, but not different at E17.5. Cardiac AT1aR, Bax, and IGF-1 mRNA expression was significantly increased by DEX compared to SAL at E17.5. In 12-month-old offspring DEX exposure caused an increase in basal blood pressure of ~3 mmHg. In addition, DEX exposed mice had a widened pulse pressure compared to SAL. DEX exposed males at 12 months had an approximate 25% reduction in nephron number compared to SAL, but no difference in cardiomyocyte number. Exposure to DEX in utero appears to adversely impact on nephrogenesis and heart growth but is not associated with a cardiomyocyte deficit in male mice in adulthood, possibly due to compensatory growth of the myocardium following the initial insult. However, the widened pulse pressure may be indicative of altered vascular compliance.
School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.
Lee
L
O'Sullivan
James S M
JS
Cuffe
Tamara M
TM
Paravicini
Sally
S
Campbell
Hayley
H
Dickinson
Reetu R
RR
Singh
Oksan
O
Gezmish
M Jane
MJ
Black
Karen M
KM
Moritz
D000375:Aging / Q000473:pathology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003907:Dexamethasone / Q000009:adverse effects*; D005260:Female; D005317:Fetal Growth Retardation / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D005333:Fetus; D015870:Gene Expression / Q000187:drug effects; D005865:Gestational Age; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D032383:Myocytes, Cardiac / Q000187:drug effects; D009399:Nephrons / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000819:agonists / Q000235:genetics / Q000378:metabolism
C494827:Bax protein, mouse; D018340:Receptors, Adrenergic, alpha-1; D051028:bcl-2-Associated X Protein; C519530:insulin-like growth factor-1, mouse; D007334:Insulin-Like Growth Factor I; D003907:Dexamethasone