Abstract P386: Effects of Saccharina Japonica Intake on Blood Pressure in 2-Kidney, 1-Clip Renovascular Hypertensive Rats fed a High-Sodium Diet

Abstract

Objective: One of foods to Japanese cuisine “Washoku” is algae, including Saccharina japonica (SJ). The intake of SJ is reported to decrease blood pressure (BP) in spontaneously hypertensive rats in some studies, and in 2-kidney, 1-clip hypertensive (2K1C) rats in our studies. Water soluble-alginate is rich in SJ. Since alginate has a physiological function to suppress sodium absorption in the gastrointestinal tract, SJ intake may alleviate hypertension to the extent according to the salt intake in 2K1C rats. In the present study, we observed the effects of SJ intake on BP in 2K1C rats fed a normal-sodium (NS) or high-sodium (HS) diet. Methods: Male Sprague-Dawley rats (6 wks) were treated with sham operation (SHAM) or clipping the left renal artery (2K1C). After surgery, the rats started receiving a NS (0.7% NaCl) or HS diet (6.0% NaCl), with or without 5.0% (w/w) SJ for 6 consecutive weeks. Systolic BP (SBP) was measured by a tail-cuff method every week. At the end of the protocol, mean arterial pressure (MAP) was measured in each rat under anesthesia. Results and Discussion: Analysis of variance showed that SBP was significantly higher in 2K1C-NS-CTL than in SHAM-NS-CTL through the experiment period (P<0.001, Fig), and that SBP was higher in 2K1C-HS-CTL than in 2K1C-NS-CTL (P<0.05). It also demonstrated that 2K1C-HS-SJ provided a significant reduction in SBP compared with 2K1C-HS-CTL (P<0.05), while there were no significant differences in SBP between 2K1C-NS-CTL and 2K1C-NS-SJ. At the end of the protocol, MAP showed the similar trend to SBP. These results suggested that the intake of SJ decreases BP, probably by suppressing sodium absorption in 2K1C rats.