Origin of aldosterone in the rat heart
Origin of aldosterone in the rat heart
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DOI：
10.1210/en.2004-0295
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发表时间：
2004-11-01
期刊：
影响因子：
4.8
通讯作者：
Gomez-Sanchez, CE
中科院分区：
文献类型：
--
作者：
Gomez-Sanchez, EP;Ahmad, N;Gomez-Sanchez, CE
已在异位大鼠心脏的灌注液和心脏匀浆中证明了醛固酮；然而，心脏中醛固酮的来源存在争议，一些人报告称其主要作用是心脏内肾上腺外合成，而另一些人则发现心脏中的所有醛固酮都与循环隔离。为了解决这一争议，我们在组织收获前测量了正常盐（NS）、低盐（LS）或高盐（HS）饮食、肾上腺切除（ADX+HS）以及醛固酮替代或脱氧皮质酮过量（ADX+HS+DOC）的ADX大鼠血浆和心脏的醛固酮和皮质酮含量。饮食中的钠含量对血浆或心脏中的皮质酮水平没有显着影响。与NS相比，LS显着增加，而HS降低血浆和心脏的醛固酮含量。 ADX-HS 大鼠的血浆和心脏中的皮质酮水平以及血浆中的醛固酮水平在大多数个体中检测不到，并且在极少数个体中极低。尽管无法检测到血浆醛固酮，但在 84ADX+HS 大鼠 30% 的心脏中可检测到醛固酮，尽管水平较低。 ADX+HS+DOC心脏中醛固酮和皮质酮含量与ADX+HS相似，表明醛固酮合酶和11β-羟化酶而非底物是心脏中肾上腺外合成皮质类固醇的限制因素。总之，我们发现健康大鼠体内醛固酮含量水平显着低于其他地方报道的水平，反映了完整大鼠的血浆水平。
Aldosterone has been demonstrated in the perfusate of the ex situ rat heart and heart homogenates; however, the origin of aldosterone in the heart is controversial, with some reporting a primary role for extraadrenal synthesis within the heart, and others finding that all of the aldosterone in the heart is sequestered from the circulation. In an attempt to resolve this controversy, we measured the aldosterone and corticosterone contents of plasma and hearts of rats on a normal salt (NS), low salt (LS), or high salt (HS) diet, adrenalectomized (ADX+HS), and ADX with aldosterone replacement or deoxycorticosterone excess (ADX+HS+DOC) before tissue harvest. The sodium content of the diet had no significant effect on corticosterone levels in the plasma or heart. LS significantly increased, whereas HS decreased the aldosterone content of plasma and heart compared with NS. Corticosterone levels in both plasma and heart and aldosterone levels in plasma of ADX-HS rats were undetectable in most individuals and were extremely low in very few. Although plasma aldosterone was undetectable, aldosterone was measurable in 30% of the hearts of 84ADX+HS rats, albeit at low levels. The aldosterone and corticosterone contents of the hearts of ADX+HS+DOC were similar to those of ADX+HS, indicating that aldosterone synthase and 11beta-hydroxylase, not substrate, are the limiting factors for extraadrenal synthesis of corticosteroids in the heart. In conclusion, we found that the level of aldosterone content in the healthy rat heart in vivo is significantly lower than that reported elsewhere and reflects plasma levels in intact rats.