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Blood-brain barrier permeability during dopamine-induced hypertension in fetal sheep.
- Source :
-
Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2001 Jul; Vol. 91 (1), pp. 123-9. - Publication Year :
- 2001
-
Abstract
- Dopamine is often used as a pressor agent in sick newborn infants, but an increase in arterial blood pressure could disrupt the blood-brain barrier (BBB), especially in the preterm newborn. Using time-dated pregnant sheep, we tested the hypothesis that dopamine-induced hypertension increases fetal BBB permeability and cerebral water content. Barrier permeability was assessed in nine brain regions, including cerebral cortex, caudate, thalamus, brain stem, cerebellum, and spinal cord, by intravenous injection of the small tracer molecule [(14)C]aminoisobutyric acid at 10 min after the start of dopamine or saline infusion. We studied 23 chronically catheterized fetal sheep at 0.6 (93 days, n = 10) and 0.9 (132 days, n = 13) gestation. Intravenous infusion of dopamine increased mean arterial pressure from 38 +/- 3 to 53 +/- 5 mmHg in 93-day fetuses and from 55 +/- 5 to 77 +/- 8 mmHg in 132-day fetuses without a decrease in arterial O(2) content. These 40% increases in arterial pressure are close to the maximum hypertension reported for physiological stresses at these ages in fetal sheep. No significant increases in the brain transfer coefficient of aminoisobutyric acid were detected in any brain region in dopamine-treated fetuses compared with saline controls at 0.6 or 0.9 gestation. There was also no significant increase in cortical water content with dopamine infusion at either age. We conclude that a 40% increase in mean arterial pressure during dopamine infusion in normoxic fetal sheep does not produce substantial BBB disruption or cerebral edema even as early as 0.6 gestation.
- Subjects :
- Aminoisobutyric Acids administration & dosage
Aminoisobutyric Acids blood
Animals
Blood Pressure
Brain embryology
Dose-Response Relationship, Drug
Hypertension physiopathology
Sheep embryology
Blood-Brain Barrier
Capillary Permeability
Dopamine
Fetus physiology
Hypertension chemically induced
Hypertension metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 8750-7587
- Volume :
- 91
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of applied physiology (Bethesda, Md. : 1985)
- Publication Type :
- Academic Journal
- Accession number :
- 11408422
- Full Text :
- https://doi.org/10.1152/jappl.2001.91.1.123