Reduction of Myocardial Stunning by in Situ Genetic Alteration of Myocytes

Direct gene transfer and stable expression in skeletal and cardiac myocytes results from simple injection of DNA into muscle tissue. To test the possibility that overexpression of Superoxide dismutase (SOD) may decrease ischemia-induced reperfusion injury to myocytes, we injected a plasmid (PMTSOD) containing the sheep metallothionein promoter and cDNA for human Cu-Zn SOD into rat left ventricles in situ. A monoclonal anti-human CuZn SOD which does not cross-react with rat endogenous SOD was used to detect human SOD. Two to 14 days after injection of 400 μg pMTSOD, strong binding of anti-human CuZn SOD was observed on the surface and interior of myocytes near the injection site. In a 1 mm² area centered on the injection site, the apparent transformation efficiency was approximately 3%; however overall levels of transformation appeared to be much lower. A possible explanation for low transformation efficiency by intramuscular injection is the inability of plasmid DNA to diffuse far beyond the injection site. It was reasoned that DNA injected into the pericardial fluid might be distributed through the cardiac lymph, and transformation of myocytes may occur throughout the heart. Therefore pMTSOD was injected into the pericardium with the expectation that cytoplasmic SOD levels would be elevated resulting in an increased resistance to reperfusion injury. Two days following intrapericardial injection of the plasmid, hearts were subjected to ischemia and reperfusion and recovery was measured. These hearts showed no evidence of myocardial stunning and no significant functional differences when compared to control hearts not subjected to ischemia. SOD levels were determined to be higher in hearts treated with pMTSOD as compared to sham-injected hearts (significance p(.06) level).

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Biology

Grantor

Southwest Texas State University

Year dc:date.issued

1993

Author dc:creator

• Toliver, Tracy E.

Advisor dc:contributor.advisor

• Koke, Joseph R.

Committee members dc:contributor.committeemember

• Walter, Ronald B.
• Irvin, James D.

• myocardium
• genetic transformation
• gene expression
• genetic regulation
• DNA
• plasmids
• rats

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10877/22299

OAI identifier oai:identifier

oai:digital.library.txst.edu:10877/22299