Oxidative stress in hypertensive,diabetic, and diabetic hypertensive rats

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.