Zinc Deficiency Exacerbates Loss in Blood‐Brain Barrier Integrity Induced by Hyperoxia Measured by Dynamic MRI

Abstract. Using dynamic Magnetic Resonance Imaging (dMRI), blood‐brain barrier (BBB) permeability (kPSρ) and tissue interstitial leakage space (ve) were evaluated in zinc‐deficient (ZnDF) male weanling Wistar rats following 3 days exposure to hyperoxia (85% O2). Temporal monitoring of T1‐weighted MR image changes, following a bolus intravenous injection of gadolinium‐DTPA, allowed estimation of BBB integrity. Three‐day exposure of hyperoxia caused a marginal loss of BBB integrity, reflected in a slight increase in kPSρ and ve, observed in both the animals fed adequate zinc (ZnAL) and pair‐fed controls (ZnPF). However, zinc deficiency resulted in a significant increase in both kPSρ and ve, indicating a severely disturbed BBB. In addition MR‐visible free water was elevated in ZnDF brains following hyperoxia treatment indicating that a loss of BBB integrity may be associated with neuronal edema. The diminished BBB integrity may be free‐radical mediated as the ratio of oxidized to reduced glutathione (GSSG:GSH) was significantly elevated.

Zinc Deficiency Exacerbates Loss in Blood‐Brain Barrier Integrity Induced by Hyperoxia Measured by Dynamic MRI Journal Articles