以鮪魚蒸煮汁之水解物作為抗高血壓劑之研究   全文下載

Hydrolysates from Tuna Cooking Juice as an Anti-hypertensive Agent

應用商業化蛋白?- orientase（來自Bacillus subtilis）由鮪魚蒸煮液（含4%蛋白質）製備對血管張力素轉換?（angiotensin i-converting enzyme，ACE）具抑制力之蛋白質水解物（ o a H ）。以自發性高血壓老鼠（spontaneously hypertensive rats，SHr）經口餵食水解物0.25、0.5、1.0 g OAH /kg體重，餵食2 hr後血管收縮壓（systolic blood pressure，SBP）依序下降18、22 及30 mm Hg。這顯示降血壓效果與劑量成正相關。oaH藉由膠過濾分離可獲得顯著降低SHr老鼠之SBP的區分物（分子量240-565 da）；雖然SHr老鼠之SBP會逐漸回復至原高血壓值，但此一效應隨著劑量不同，可維持2-10 hr。此外，SHr老鼠的SBP隨著成長時間會逐漸上升，於15週齡時可達215 mmHg；然而餵食含0.25%、1.25%及2.5% oaH飼料的SHr老鼠，其SBP先下降再上升，並分別維持於200、205及215 mmHg。這些結果顯示鮪魚蒸煮液蛋白質為製備具調節血壓之aCE抑制劑的潛力來源。

Tuna cooking juice containing 4% protein was hydrolyzed using a commercial protease, Orientase from Bacillus subtilis, to prepare hydrolysate (OAH) that inhibits angiotensin I-converting enzyme (ACE). The systolic blood pressure (SBP) dropped by 18 mmHg in spontaneously hypertensive rats (SHR) 2hr after being orally administered the hydrolysate at 0.25g hydrolysate/kg body weight, and reduced, from 172 mmHg to 150 and 142 mmHg for those administered with lyophilized OAH at 0.5 and 1.0 g/kg body weight, respectively. This indicated that the lowering effect on SBP was dose-dependent. Constituents derived from the gel filtration of OAH with molecular weight ranging from 240-565 Da exerted an obvious effect on SBP. Although the reduced SBP in SHR gradually returned to the original level, the reduction effect lasted for 2-10 hr, depending on the dose. The SBP of SHR fed on a normal diet increased gradually to 215 mmHg by the age of 15 weeks, while it decreased, then increased to and stayed at, respectively, 200, 205 and 215 mmHg for those fed on diets containing 2.5, 1.25 or 0.25% lyophilized OAH. This result showed that proteins in tuna cooking juice are potential source of ACE-inhibiting agent, and thus may be useful to regulate the blood pressure.