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.