[Effect of fish protein on blood pressure, glycemia and plasma and urinary parameters in spontaneously hypertensive rats (SHR) and diabetic SHR].

Fish protein (FP) effect compared to casein (CAS) was studied on blood pressure (BP) evolution and glycemia in part, and on plasma lipid, angiotensine II and aldosterone concentrations and urinary aldosterone on the other hand, in SHR and in SHR with streptozotocin-induced diabetes (SHR-STZ). Two groups of rats (6 SHR and 6 SHR-STZ) were fed for 2 months diet containing 20% CAS or 20% FP. One month before sacrifice, diabetes was induced into one group of rats by a single intraperitonealy injection of streptozotocin (STZ). The results showed that FP diminished blood pressure (-9%) in SHR, compared with CAS. In contrast, FP enhanced significantly blood pressure in SHR-STZ vs SHR (p<0.01). There was no effect on glycemia with fish protein. FP compared to CAS involved a diminution (-41%) and (-17%) of total cholesterol and (-26%) and (-9%) of phospholipids in SHR and SHR-STZ, respectively. Moreover, a decrease of triacylglycerols (-21%) was noted in SHR-STZ with FP vs CAS. In SHR, plasma aldosterone and angiotensine II concentrations were reduced (-62%) and (-64%) and urinary aldosterone amounts were enhanced with FP compared to CAS (p<0.05). In SHR-STZ group, aldosterone value was fivefold lower in plasma and twofold higher in urine with FP compared to CAS. A significant enhancement of urinary aldosterone was noted in SHR-STZ vs SHR whatever diet-consumed. In conclusion, FP has a beneficial effect on blood pressure by modulating the hypertension markers i.e. plasma total cholesterol, angiotensine II and aldosterone, in SHR group, and on total cholesterol and triglycerids in SHR-STZ. FP reduces plasma aldosterone by its enhanced urinary excretion. It is necessary to specify the action mode of FP in order to propose it as nutritional complement in the degenerative diseases such as hypertension and diabetes.