[The protective effect of MPEG-SOD on the function of left ventricle during acute hypoxia].
Monomethoxypolyethylene glycol (MPEG) was attached covalently to superoxide dismutase (SOD, EC1.15.1.1). The molecular weight of MPEG-SOD was about 7.0 x 10(5) Dalton determined by Fast Protein Liquid Chromatography (FPLC with Sepharose 6 HR10/30). MPEG-SOD exhibited a sharply enhanced serum half life (more than 30 h) than that of the native SOD (6-10 min). To determine the role of MPEG-SOD in acute hypoxia-induced injury of left ventricular function, heart rate (HR), arterial pressure (AP), left ventricular pressure (LVP) and dp/dt (LV +/- dp/dtmax) were measured in male SD rats divided into three groups: Control group (n = 8, intravenously injected with physiological saline), native SOD group (n = 8,800 U SOD i. v.) and MPEG-SOD group (n = 9,800 U MPEG-SOD i. v.). LVP, LV +/- dp/dtmax, AP and HR showed no significant difference among these three groups before hypoxia. But in acute hypoxia simulating altitude of 6,000-6,500 m, LVP, LV+dp/dtmax and AP were decreased in the control group, while in MPEG-SOD group they were all increased compared with those in control group (P < 0.05, P < 0.01). There were no significant difference between control group and native SOD group. The results indicate that MPEG-SOD has a protective effect on the injury of myocardial function induced by acute hypoxia, and suggest that acute hypoxia cause increase of superoxide free radical (O2.-) and other derivative radicals damaging membrane system of the cell.
Han
Z Y
ZY
Physiological Laboratory of Hypoxia, Shanghai Institute of Physiology, Chinese Academy of Sciences.
Chen
M
M
Wang
Q H
QH
Zhou
Z N
ZN
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005609:Free Radicals; D006339:Heart Rate / Q000187:drug effects; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010100:Oxygen / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology*; D051381:Rats; D013482:Superoxide Dismutase / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects*
D005609:Free Radicals; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol; D013482:Superoxide Dismutase; D010100:Oxygen