Reddy S R, Talwalkar R, Downs J, Kotchen T A
Department of Medicine, West Virginia University School of Medicine, Morgantown 26506.
Am J Physiol. 1989 Aug;257(2 Pt 2):H611-7. doi: 10.1152/ajpheart.1989.257.2.H611.
High dietary intake of linoleic acid lowers arterial pressure, and, in vitro, linoleic acid inhibits the enzymatic activity of renin. The purpose of the present study was 1) to evaluate the effect of intravenous infusion of linoleic acid on blood pressure in normotensive and hypertensive Sprague-Dawley rats and 2) to determine whether the hypotensive response to linoleic acid infusion is caused by inhibition of circulating renin. Blood pressure was decreased (P less than 0.01) by linoleic acid infusion in normotensive sodium chloride-deprived animals and in animals with two-kidney, one-clip hypertension. In contrast, linoleic acid infusion did not affect blood pressure in normotensive rats on a "normal" or high sodium chloride intake, in rats with deoxycorticosterone acetate (DOCA)-salt hypertension, and in anephric rats. In sodium chloride-deprived rats, the reduction of blood pressure by linoleic acid infusion was associated with increased plasma renin activity (P less than 0.05); serum angiotensin-converting enzyme activity was unchanged. The in vitro enzymatic activity of exogenous renin in plasma of anephric rats was not affected by linoleic acid infusion. In two-kidney, one-clip hypertensive animals, pretreatment with indomethacin did not alter the hypotensive response to linoleic acid. Thus, although linoleic acid infusion lowered blood pressure in high renin but not in low renin states, the reduction of blood pressure was not related to inhibition of circulating renin or to alterations of endogenous prostaglandin biosynthesis.
饮食中高亚油酸摄入量可降低动脉血压，并且在体外实验中，亚油酸可抑制肾素的酶活性。本研究的目的是：1）评估静脉输注亚油酸对正常血压和高血压的斯普拉格-道利大鼠血压的影响；2）确定输注亚油酸后的降压反应是否由循环肾素的抑制引起。在正常血压的缺氯化钠动物和两肾一夹高血压动物中，输注亚油酸可使血压降低（P<0.01）。相比之下，在摄入“正常”或高氯化钠的正常血压大鼠、醋酸脱氧皮质酮（DOCA）-盐高血压大鼠和无肾大鼠中，输注亚油酸对血压没有影响。在缺氯化钠的大鼠中，输注亚油酸导致的血压降低与血浆肾素活性增加相关（P<0.05）；血清血管紧张素转换酶活性未改变。无肾大鼠血浆中外源性肾素的体外酶活性不受输注亚油酸的影响。在两肾一夹高血压动物中，用吲哚美辛预处理不会改变对亚油酸的降压反应。因此，尽管输注亚油酸在高肾素状态下可降低血压，但在低肾素状态下则不然，血压降低与循环肾素的抑制或内源性前列腺素生物合成的改变无关。
