Loading...
Please wait, while we are loading the content...
Similar Documents
Early gestation dexamethasone programs enhanced postnatal ovine coronary artery vascular reactivity.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Roghair, Robert D. |
| Copyright Year | 2005 |
| Abstract | Excessive exposure of the fetus to maternally derived corticosteroids has been linked to the development of adult-onset diseases. To determine if early gestation corticosteroid exposure alters subsequent coronary artery reactivity, we administered dexamethasone (0.28 mg.kg(-1).day(-1)) to pregnant ewes at 27-28 days gestation (term being 145 days). Vascular responsiveness was assessed in endothelium-intact coronary and mesenteric arteries isolated from steroid-exposed and age-matched control fetal sheep at 123-126 days gestation and lambs at 4 mo of age. Lambs exposed to maternal dexamethasone had higher mean arterial blood pressures than the age-matched controls (93 +/- 3 vs. 83 +/- 5 mmHg, P < 0.05). Mesenteric arteries from the steroid-exposed fetuses displayed diminished responses to ANG II, relative to controls. In 4-mo-old lambs, prenatal dexamethasone exposure significantly increased coronary artery vasoconstriction to ANG II, ACh, and U-46619, but not KCl. In contrast, postnatal mesenteric artery reactivity was unaltered by steroid exposure. Compared with fetal mesenteric reactivity, postnatal mesenteric reactivity to ANG II, phenylephrine, and U-46619 was diminished, whereas the response to 120 mmol/l KCl was heightened. Coronary artery ANG II receptor protein expression was not significantly altered by steroid exposure in either age group. These findings demonstrate that early-gestation glucocorticoid exposure programs postnatal elevations in blood pressure and selectively enhances coronary artery responsiveness to second messenger-dependent vasoconstrictors. Glucocorticoid-induced alterations in coronary vascular smooth muscle structure or function may provide a mechanistic link between an adverse intrauterine environment and later cardiovascular disease. |
| Starting Page | 5s |
| Ending Page | 7s |
| Page Count | 3 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ajpregu.physiology.org/content/ajpregu/288/1/R46.full.pdf |
| Alternate Webpage(s) | http://ajpregu.physiology.org/content/ajpregu/288/1/r46.full.pdf |
| PubMed reference number | 15217789v1 |
| Volume Number | 288 |
| Issue Number | 1 |
| Journal | American journal of physiology. Regulatory, integrative and comparative physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Acetylcholine Adrenal Cortex Hormones Cardiovascular Diseases Dexamethasone Domestic Sheep Fetus Intrauterine Mesenteric Arteries Mesentery Muscle, Smooth, Vascular Phenylephrine Potassium Chloride Smooth muscle (tissue) Steroids U-44619 Vascular constriction (function) Vasoconstrictor Agents millimole receptor torr |
| Content Type | Text |
| Resource Type | Article |
