These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Modulation of aldosterone synthase messenger ribonucleic acid levels by dietary sodium and potassium and by adrenocorticotropin.
    Author: Holland OB, Carr B.
    Journal: Endocrinology; 1993 Jun; 132(6):2666-73. PubMed ID: 8389287.
    Abstract:
    Recent evidence suggests that an aldosterone synthase (AS) separate from the 11 beta-hydroxylase (11 beta-OHase) mediates the final step(s) in aldosterone synthesis in the rat. We have compared changes in AS and 11 beta-OHase mRNA levels with experimental maneuvers known to stimulate or suppress aldosterone secretion. In Exp 1, male rats were fed regular rat chow (group 1), a low sodium, high potassium diet (group 2), or a high sodium, low potassium diet (group 3). Northern analysis of adrenal capsular (zona glomerulosa) and decapsulated adrenal core (fasciculata-reticularis) tissues was performed with specific oligonucleotide probes for AS and 11 beta-OHase mRNAs, normalized with a cDNA probe for 18S ribosomal RNA (rRNA). There was a marked increase in capsular AS mRNA in group 2 rats compared to levels in group 1 (P < 0.0001) and group 3 (P < 0.0001) rats. Capsular As mRNA decreased (P < 0.05) in group 3 compared to that in group 1 rats. Adrenal core AS mRNA levels were quite low with all three diets. In contrast, capsular and core 11 beta-OHase mRNA levels did not change significantly with diet. In Exp 2, two groups served as controls (groups 1 and 3), and two groups received sc injections of repository ACTH (groups 2 and 4). Control and ACTH-treated rats were killed 3 h (groups 1 and 2) or 24 h (groups 3 and 4) after initial ACTH administration. Capsular and core AS and 11 beta-OHase mRNA levels were evaluated with and without normalization with 18S rRNA, cyclophilin, and glyceraldehyde phosphate dehydrogenase housekeeping probes. Capsular AS mRNA increased at 3 h (P < 0.05), but decreased at 24 h (P < 0.01). Nonnormalized adrenal capsular and core 11 beta-OHase mRNA levels were unchanged at 3 h, but increased significantly at 24 h (P < 0.05) in capsular tissue of ACTH-treated rats. However, in ACTH-treated rats, 18S rRNA and cyclophilin mRNA levels increased at 24 h in both capsular and core tissue (P < 0.01), and glyceraldehyde phosphate dehydrogenase mRNA levels increased in capsular tissue (P < 0.00001), resulting in a lack of change in normalized 11 beta-OHase mRNA. Changes in cholesterol side-chain cleavage were similar to those in 11 beta-OHase mRNA. These data provide further evidence that a separate AS plays a significant role in modulating aldosterone secretion in rodents.
    [Abstract] [Full Text] [Related] [New Search]