Dexamethasone alters vascular reactivity by enhancing COX-related vasodilatation in fetal ovine carotids.
نویسندگان
چکیده
Based on preliminary studies that contractile efficacy was altered in vertebral and basilar arteries from neonatal donors treated with postnatal glucocorticoids, we examined the hypothesis that postnatal dexamethasone (DEX), a glucocorticoid used for respiratory disease in neonates, can alter vascular reactivity. Using near-term fetal lamb carotids, we measured 5-hydroxytryptamine (5-HT) dose-response relationship in DEX-treated and untreated arteries. We found that DEX incubation for 1 h had no effect on 5-HT sensitivity and agonist affinity but significantly reduced 5-HT contractile efficacy, a response that became even more pronounced after 4 h of DEX treatment. Coincubation of DEX-treated arteries with INDO for 4 h reversed this DEX-induced attenuation in 5-HT contractile efficacy, although DEX had no significant effects on cyclooxygenase (COX)-1 and COX-2 protein abundance. This data suggests that DEX alters vascular reactivity through a COX-related mechanism, with possible repercussions to neurological injury.
منابع مشابه
CALL FOR PAPERS Fetal Physiological Programming Early gestation dexamethasone programs enhanced postnatal ovine coronary artery vascular reactivity
Roghair, Robert D., Fred S. Lamb, Francis J. Miller, Jr. Thomas D. Scholz, and Jeffrey L. Segar. Early gestation dexamethasone programs enhanced postnatal ovine coronary artery vascular reactivity. Am J Physiol Regul Integr Comp Physiol 288: R46–R53, 2005. First published June 24, 2004; doi:10.1152/ajpregu.00165. 2004.—Excessive exposure of the fetus to maternally derived corticosteroids has be...
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ورودعنوان ژورنال:
- Biology of the neonate
دوره 90 1 شماره
صفحات -
تاریخ انتشار 2006