1. ¹A.J. Chorley Institute for Hypertension, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
2. ²Lumitest Ltd., Nesher, Israel

Correspondence: Dr. Talma Rosenthal, Chorley Institute for Hypertension Research, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel E-mail: rtalma@post.tau.ac.il

Received 23 April 2003; Revised 3 June 2003; Accepted 17 July 2003.

Abstract

Background: Reactive oxygen species play a key role in the formation of endothelial dysfunction accompanying diabetes mellitus, hypertension, and other cardiovascular diseases.

Methods: This study compares oxidative stress (OS) in Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), non–insulin-dependent Cohen Diabetic rats (CDR), and Cohen Rosenthal diabetic hypertensive rats (CRDH), a unique animal model of both diabetes and hypertension. The OS was evaluated with a newly developed thermochemiluminiscence (TCL) analyzer (Lumitest Ltd., Nesher, Israel) that measures the oxidizability (ie, susceptibility to oxidation) of a test sample.

Results: The TCL oxidizability test results of sera from the different rats groups showed a time-dependent increase in TCL of up to 145% 7% for WKY, 160% 8% for SHR, 179% 12% for CDR, and 226% 15% for CRDH. These results were significant: P < .001 for SHR and CDR and P < .0001 for CRDH in comparison to WKY. Lipid peroxide levels also increased in each strain of rats: to 80 7.8 nmol/mL in WKY, 104 10.1 nmol/mL in SHR, 110 9.4 nmol/mL in CDR, and 167 11.7 nmol/mL in CRDH. These results were also significant: P < .001 for SHR, CDR and CRDH in comparison to WKY.

Conclusion: The combination of hypertension and diabetes is accompanied by higher oxidative stress than that seen with either disorder alone.