Prolonged fasting increases the response of the renin-angiotensin-aldosterone system, but not vasopressin levels, in postweaned northern elephant seal pups.
Prolonged fasting increases the response of the renin-angiotensin-aldosterone system, but not vasopressin levels, in postweaned northern elephant seal pups.
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DOI：
10.1006/gcen.2000.7514
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发表时间：
2000-08
影响因子：
2.7
通讯作者：
Rudy M. Ortiz;Rudy M. Ortiz;Charles E. Wade;C. Ortiz
中科院分区：
文献类型：
--
作者：
Rudy M. Ortiz;Rudy M. Ortiz;Charles E. Wade;C. Ortiz
北象海豹幼崽断奶后8 ~ 12周的禁食对其体液和电解质稳态没有明显的有害影响。然而，在禁食期间，抗利尿激素（AVP）的作用已被证明是不确定的，肾素-血管紧张素-醛固酮系统（RAAS）的参与尚未被检查。为了研究长时间禁食对这些渗透调节激素的影响，在禁食的前49天，对15只断奶后的幼崽进行了连续的血液采样。禁食没有引起离子或渗透浓度的显著变化，提示电解质稳态。到禁食第21天，总蛋白减少，并保持低水平，表明缺乏脱水。在禁食的前49天，醛固酮和血浆肾素活性呈相关线性增加，表明RAAS活跃。在禁食期间，醛固酮呈抛物线趋势，在第35天达到峰值，表明在禁食后期肾脏对醛固酮的敏感性发生了变化。AVP仅在第49天升高，但浓度相对较低。RAAS在断奶后的禁食期间被修改，似乎在这一时期的电解质和水稳态调节中发挥重要作用。
The 8- to 12-week postweaning fast exhibited by northern elephant seal pups (Mirounga angustirostris) occurs without any apparent deleterious effects on fluid and electrolyte homeostasis. However, during the fast the role of vasopressin (AVP) has been shown to be inconclusive and the involvement of the renin-angiotensin-aldosterone system (RAAS) has yet to be examined. To examine the effects of prolonged fasting on these osmoregulatory hormones, 15 postweaned pups were serially blood-sampled during the first 49 days of their fast. Fasting did not induce significant changes in ionic or osmotic concentrations, suggesting electrolyte homeostasis. Total proteins were reduced by day 21 of fasting and remained depressed, suggesting a lack of dehydration. Aldosterone and plasma renin activity exhibited a correlated, linear increase over the first 49 days of the fast, suggesting an active RAAS. Aldosterone exhibited a parabolic trend over the fast with a peak at day 35, suggesting a shift in the sensitivity of the kidney to aldosterone later in the fast. AVP was elevated at day 49 only, but concentrations were relatively low. RAAS was modified during the postweaning fast in pups and appears to play a significant role in the regulation of electrolyte and, most likely, water homeostasis during this period.