Disturbed brain purine metabolism results in a gross opening of the blood-brain barrier in newborn piglets following experimental pneumothorax.
Changes in the permeability of pial-arachnoideal microvessels [30-210 microns), of the blood-brain barrier (BBB), were intravitally studied by fluorescent microscopy and compared to the hypoxanthine (HX) level of cerebrospinal fluid (CSF) in newborn piglets (n = 24) using the open cranial window technique. Eight animals served as controls (Group 1), the others were studied in the course of bilateral experimental pneumothorax (BEP) using low (Na(+)-fluorescein, MW 376, Group 2) and large molecular weight (FITC dextran, MW 40,000, Group 3) fluorescent tracer molecules. Cisternal CSF was sampled from the animals: 8 piglets from Group 1, and 4-4 piglets from Groups 2 and 3 at different stages of pathological condition: (i) at the critical (C) stage (severe acidosis, bradycardia, arterial hypotension and hypoxaemia) and also (ii) at the recovery (R) stage (mild metabolic acidosis, tachycardia, arterial hypotension) and the HX concentration was determined with high-pressure liquid chromatography. In Group 1 neither low (n = 4) nor large (n = 4) molecular weight tracers penetrated BBB. In Group 2, however, the fluorescein dye passed BBB as a spotty leakage in animals at C stage (n = 8). Diffuse fluorescein penetration was seen at R stage, too (n = 4). In Group 3 no change in permeability was found at C stages (n = 8), but at R stage (n = 4), 2 h after the primary hypoxic insult, when the animals had recovered from cardiovascular and metabolic shock, the tracer passed locally the microvascular wall and appeared as leaky spots (number of leaky sites = 2.3 +/- 0.4/0.10 cm2, means +/- SE).(ABSTRACT TRUNCATED AT 250 WORDS)
Temesvári
P
P
Department of Pediatrics, Szent-Györgyi Albert University Medical School, Szeged, Hungary.
Abrahám
C
C
Joó
F
F
Kovács
J
J
Baranyai
Z
Z
Rácz
K
K
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism* / Q000502:physiology; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism*; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000378:metabolism; D011031:Pneumothorax, Artificial; D011687:Purines / Q000378:metabolism*; D013552:Swine
D007042:Hypoxanthines; D011687:Purines; D019271:Hypoxanthine