Increased platelet-activating factor-induced periventricular brain microvascular constriction associated with immaturity

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2003-04, Vol.53 (4), p.R928-R935
• Main Authors: XIN HOU, GOBEIL, Fernand JR, PERI, Krishna, VARMA, Daya R, CHEMTOB, Sylvain, MARRACHE, Anne Marilise, QUINIOU, Christiane, BRAULT, Sonia, CHECCHIN, Daniella, BERNIER, Sylvie G, SENNLAUB, Florian, JOYAL, Jean-Sebastien, ABRAN, Daniel
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blood vessels; Brain; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; Fundamental and applied biological sciences. Psychology; Vertebrates: nervous system and sense organs
• ISSN: 0363-6119; 1522-1490

Oxidant stress contributes to the pathogenesis of hypoxic-ischemic encephalopathies. Platelet-activating factor (PAF) is generated during oxidant stress. We studied the vasomotor mode of actions of PAF on periventricular (PV) microvessels of fetal (75% of term), newborn (1-3 days), and adult pigs. PAF constricted PV microvessels from fetal (29.27 ± 2.6%) and newborn (22.14 ± 3.2%) pigs but was ineffective in adults ( newborn>adult profile. Thus the greater PAF-induced PV microvascular constriction in younger subjects seems attributable to greater PAF receptor density and mostly secondary to TXA2 formation from endothelium. The resulting decrease in blood flow may contribute to the increased vulnerability of the PV brain regions to oxidant stress-induced injury in immature subjects. [PUBLICATION ABSTRACT]