Background:We measured the effects of fish protein (FP) on blood pressure, glycemia and antioxidant status in spontaneously hypertensive (SH) rats with streptozotocin-induced diabetes (STZ).Material/Methods: Two groups of 12 rats each were fed 20% casein (C) or FP for 2 months. The total antioxidant status of blood and organs (liver, kidney and heart) was measured by the KRL™ test. Antioxidant enzyme activities (G-Px, G-Red, and SOD) and antioxidant substances (GSH, NO) were determined in organs, and vitamin C in plasma.Results: FP lowered blood pressure in SH rats, but not in SH-STZ. Blood and plasma antioxidant status increased 35% and 9%, respectively, with FP in SH-STZ compared to SH rats; when compared to C, these values were more enhanced. SOD activity values were elevated with FP in SH-STZ rats, compared to the C diet, regardless of organ. Higher kidney NO and heart GSH values were noted in SH-STZ rats than SH. In SH rats fed FP, the GSH value was 2.26 times higher in liver, and NO was 3 times higher in heart. Higher NO was noted in kidney (1.84 times) and heart (1.91 times), GSH in heart (1.79 times), and vitamin C in plasma (+46%) in SH-STZ rats with FP than with C.Conclusions: Fish protein has a beneficial effect on blood pressure in SH rats but not in SH-STZ, and plays an important role in antioxidative defense. This protein may be useful in future treatments of such diseases as diabetes and hypertension.

Keywords: Caseins - pharmacology, Fish Proteins - pharmacology, Myocardium - enzymology, Animal Feed, Antioxidants - metabolism, Blood Glucose - drug effects, Blood Pressure - drug effects, Caseins - pharmacology, Diabetes Mellitus, Experimental - metabolism, Erythrocytes - enzymology, Fish Proteins - pharmacology, Glutathione Peroxidase - metabolism, Glutathione Reductase - metabolism, Hypertension - metabolism, Kidney - enzymology, Liver - enzymology, Myocardium - enzymology, Rats, Inbred SHR, Superoxide Dismutase - metabolism