Evidence for the role of PO4 deficiency in antihypertensive action of a high-Ca diet.
Evidence for the role of PO4 deficiency in antihypertensive action of a high-Ca diet.
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PO4 缺乏在高钙饮食的抗高血压作用中的作用的证据。
DOI：
10.1152/ajpheart.1984.246.3.h324
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Eby,B
中科院分区：
文献类型：
--
作者：
Lau,K;Chen,S;Eby,B
先前的研究表明，高钙饮食对高血压（BP）有有益的影响。然而，其机制尚不清楚。采用平衡和清除技术，评价了雌性自发性高血压大鼠（SHR）体内甲状旁腺激素（PTH）、体积收缩、高钙血症和PO4缺乏的作用。与低钙（0.22%）或正常钙（1.2%）饮食相比，在9周龄和22周龄的慢性稳定甲状旁腺切除（PTX）大鼠（III组和IV组）中，完整动物（I组和II组）中高钙（4.3%）饮食的降压作用可以重现。在短期（7天）和长期（12周）的高钙饮食暴露中，尽管高钙血症持续到12周（10.8 vs 9.7 mg/100 ml， I组对照，P < 0.02），但没有证据表明体积收缩。当通过ip注射产生慢性高钙血症时，无论是在完整（VI组）还是PTX （IV组）大鼠中，慢性高钙血症的强度与口服钙补充剂相似，都未能降低血压。IV组大鼠的低磷血症（3.2 vs. 6.9 mg/100 ml）、低磷尿症（0.15 vs. 15 mg/天）、高镁尿症（11 vs. 7.7 mg/天），肠道PO4净吸收量（13.3 +/- 7.5 vs. 66.8 +/- 7.5 mg/天）明显低于喂食1.2%钙的大鼠。为验证po4缺乏症假说，分别饲喂钙含量为1.2%的饲粮并注射NaCl或饲喂钙含量为4.3%的饲粮，其中一半动物注射中性nabo4，一半动物注射NaCl。（摘要删节250字）
Previous studies indicated a salutary effect of a high-Ca diet on high blood pressure (BP). The mechanism, however, is obscure. With balance and clearance techniques, the role of parathyroid hormone (PTH), volume contraction, hypercalcemia, and PO4 deficiency was evaluated in female spontaneous hypertensive rats (SHR). The antihypertensive effects of a high (4.3%) Ca diet in intact animals (groups I and II) could be reproduced in both 9- and 22-wk-old chronic stable parathyroidectomized (PTX) rats (groups III and IV), when compared with a low (0.22%) or normal (1.2%) CA diet. In both short (7 days) and long (12 wk) term exposure to the high-Ca diet, evidence for volume contraction could not be documented despite hypercalcemia sustained through the 12th wk (10.8 vs. 9.7 mg/100 ml, group I control, P less than 0.02). When produced by ip injections, chronic hypercalcemia of similar magnitudes as oral Ca supplements failed to reduce BP in either intact (group VI) or PTX (group IV) rats. Rats in group IV fed the high-Ca diet displayed marked hypophosphatemia (3.2 vs. 6.9 mg/100 ml), hypophosphaturia (0.15 vs. 15 mg/day), hypermagnesiuria (11 vs. 7.7 mg/day), and drastically reduced net intestinal PO4 absorption (13.3 +/- 7.5 vs. 66.8 +/- 7.5 mg/day) compared with rats fed 1.2% Ca diet. To test the PO4-deficiency hypothesis, additional SHR (group V) were fed either 1.2% Ca diet and injected ip with NaCl or fed 4.3% Ca diet, with half of these animals injected with neutral NaPO4 and half with NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)