Polyethylene glycol-conjugated superoxide dismutase fails to augment brain superoxide dismutase activity in piglets.

Polyethylene glycol-conjugated superoxide dismutase fails to augment brain superoxide dismutase activity in piglets.

We studied the effect of intravenously administered polyethylene glycol-conjugated superoxide dismutase (8,000 units/kg) on brain superoxide dismutase activity in 44 1-2-week-old piglets in the absence and presence of global cerebral ischemia and reperfusion. Four groups (n = 6 each) of piglets not exposed to ischemia were studied. Enzyme administration increased plasma superoxide dismutase act...

Polyethylene glycol superoxide dismutase and catalase attenuate increased blood-brain barrier permeability after ischemia in piglets.

BACKGROUND AND PURPOSE Transport of urea across the blood-brain barrier is increased during postischemic cerebral reperfusion in the piglet. Ischemia/reperfusion also has been observed to increase apparent superoxide anion generation on the surface of the brain. The present study was designed to address the hypothesis that the increased transfer of urea into the brain after ischemia/reperfusion...

Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance.

Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from less than 10 min to 40 h, reduces immunogenicity, and decreases sensitivity to proteolysis. Because PEG has surface active properties and can induce cell fusion, we hypothesized that PEG conjugation could enhance cell binding and association of norm...

Brain and tissue distribution of polyethylene glycol-conjugated superoxide dismutase in rats.

BACKGROUND AND PURPOSE The purpose of this study was to determine the distribution of polyethylene glycol-conjugated superoxide dismutase in the brain, cerebrospinal fluid, and various organs. METHODS Distribution of iodine-125-labeled polyethylene glycol-conjugated superoxide dismutase was determined in three groups of male Sprague-Dawley rats: a normotensive sham control group (n = 9) and g...

Superoxide dismutase Superoxide dismutase