S100B immunoreactivity: a new marker of hypoxia-related cardiac damage in newborn piglets.

AbstractObjective: The evaluation of the expression of S100B protein, in the swine heart in an experimental model of hypoxia - reoxygenation.Methods: Normocapnic hypoxia was induced in 40 male Landrace/Large White neonatal piglets by decreasing the inspired concentration of oxygen to 6–8%. When animals developed bradycardia or severe hypotension, reoxygenation was initiated. Piglets were allocated in four groups of 10, according to the oxygen concentration they were reoxygenated with: Group 1, 2, 3 and 4 resuscitated with 18%, 21%, 40% and 100% oxygen, respectively. The animals were further classified into 4 groups according with the time required for reoxygenation: group A ( 60 min); group D (deceased animals).Results: Immunostaining for S100B protein was detected in 14 out of the 40 heart samples (35%), both inside the cytoplasm of cardiomyocytes and as globular deposits in the interstitial spaces. Significant differences were observed among groups 1–4 regarding S...