Hayashi I, Majima M, Fujita T, Okumura T, Kumagai Y, Tomita N, Morishita R, Higaki J, Ogiwara T
Department of Pharmacology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
Br J Pharmacol. 2000 Oct;131(4):820-6. doi: 10.1038/sj.bjp.0703634.
We have previously reported that the renal kallikrein-kinin system suppressed the development of deoxycorticosterone acetate (DOCA)-salt hypertension. Kinins were degraded in the kidney mainly by carboxypeptidase Y (CPY)-like kininase. Blockade of renal kinin degradation may reduce hypertension in the developmental stage. We constructed an antisense oligonucleotide against rat CPY homologue (5'-CAT-CTC-TGC-TTC-CTT-GTG-TC-3', AS) and its randomized control oligonucleotide (5'-TCC-TTC-CTG-CTT-GAG-TTC-CT-3', RC), and prepared an HVJ-liposome complex that prolongs and increases the effectiveness of the antisense oligonucleotide. Antisense oligonucleotide was transfected (25 nmole rat(-1), in terms of nucleotide) into the kidney from the renal artery. Blood pressure was measured through a catheter inserted into the abdominal aorta. Mean blood pressure (MBP) in DOCA-salt treated (for 2 weeks) Sprague Dawley strain rats was 130+/-3 mmHg (n=11), and was reduced significantly (P<0.05) more by AS transfection (122+/-4 mmHg, n=6) than by RC treatment (137+/-6 mmHg, n=5) 4 days after the transfection. This reduction in MBP was accompanied by increased urinary sodium excretion (AS, 8.4+/-1.5 mmole day(-1); RC, 4.6+/-0.5 mmole day(-1), P<0.05) and a reduction in urinary CPY-like kininase activity. Ebelactone B (5 mg kg(-1), twice a day, p.o.), an inhibitor for urinary CPY-like kininase, also reduced MBP and induced natriuresis to the same degree as AS. Lisinopril, an inhibitor for angiotensin converting enzyme (ACE) failed to reduce the elevated MBP. These results suggest that CPY-like kininase may have more contribution than ACE to degrade kinin in the kidney, and that knockdown of CPY-like kininase in the kidney may partly prevent rat DOCA-salt hypertension.
我们之前报道过，肾脏激肽释放酶 - 激肽系统可抑制醋酸脱氧皮质酮（DOCA）-盐性高血压的发展。激肽在肾脏中主要由羧肽酶Y（CPY）样激肽酶降解。阻断肾脏激肽降解可能会降低发育阶段的高血压。我们构建了针对大鼠CPY同源物的反义寡核苷酸（5'-CAT-CTC-TGC-TTC-CTT-GTG-TC-3'，AS）及其随机对照寡核苷酸（5'-TCC-TTC-CTG-CTT-GAG-TTC-CT-3'，RC），并制备了能延长和增强反义寡核苷酸有效性的HVJ - 脂质体复合物。反义寡核苷酸（以核苷酸计，25 nmol·大鼠⁻¹）通过肾动脉转染到肾脏中。通过插入腹主动脉的导管测量血压。经DOCA - 盐处理（2周）的斯普拉格 - 道利品系大鼠的平均血压（MBP）为130±3 mmHg（n = 11），转染后4天，与RC处理组（137±6 mmHg，n = 5）相比，AS转染组（122±4 mmHg，n = 6）的MBP显著降低（P<0.05）。MBP的这种降低伴随着尿钠排泄增加（AS组，8.4±1.5 mmol·天⁻¹；RC组，4.6±0.5 mmol·天⁻¹，P<0.05）以及尿CPY样激肽酶活性降低。尿CPY样激肽酶抑制剂依贝内酯B（5 mg·kg⁻¹，每日两次，口服）也使MBP降低并诱导利钠作用，程度与AS相同。血管紧张素转换酶（ACE）抑制剂赖诺普利未能降低升高的MBP。这些结果表明，CPY样激肽酶在肾脏中降解激肽方面可能比ACE起更大作用，并且敲低肾脏中的CPY样激肽酶可能部分预防大鼠DOCA - 盐性高血压。
