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: The negative effect of dexamethasone on calcium-processing gene expressions is associated with a glucocorticoid-induced calcium-absorbing disorder.
    Author: Kim MH, Lee GS, Jung EM, Choi KC, Jeung EB.
    Journal: Life Sci; 2009 Jul 17; 85(3-4):146-52. PubMed ID: 19490920.
    Abstract:
    AIMS: Although dexamethasone (Dex) is used widely as an anti-inflammatory and immunosuppressive drug, Dex appears to have severe side-effects, including osteoporosis. This study determined the effects of Dex on duodenal and renal expressions of the calcium-processing genes transient receptor potential cation channel, subfamily V, member 5/6 (TRPV5/6), calbindin-D9k/-D28k (CaBP-9k/28k), Na+/Ca2+ exchanger 1 (NCX1), and plasma membrane Ca(2+)-ATPase (PMCA) 1b. MAIN METHODS: Mice were injected subcutaneously with Dex for 1 or 5 days. The mRNA and protein expression levels of these calcium-processing genes were measured by real-time PCR and immunohistochemistry/immunoblot analysis, respectively. In addition, serum parathyroid hormone (PTH) levels were measured following Dex treatments. KEY FINDINGS: Treatment with Dex for 24 h resulted in the inductions of duodenal TRPV6, CaBP-9k and PMCA1b transcripts and renal TRPV5, CaBP-9k, and NCX1 transcripts, while it reduced the transcription of renal TRPV6. Although the expressional changes were weak, duodenal expressions of glucocorticoid receptor (GR), the vitamin D receptor (VDR), and renal expressions of the parathyroid hormone receptor (PTHR) and VDR were increased following 24 h treatment with Dex. A five-day treatment with Dex reduced the transcriptional levels of duodenal TRPV6 and CaBP-9k by 60%. Transcripts for VDR and GR in the duodenum increased marginally. SIGNIFICANCE: These results suggest that the expressions of TRPV6 and CaBP-9k in the duodenum appear to be a major regulatory target for glucocorticoids (GCs), and may be involved in the negative regulation of calcium absorption in GC-induced osteoporosis (GIO). The transcriptional regulation of TRPV6 and CaBP-9k in the duodenum seems complex given that there is an increase at 1-day treatment followed by a decrease at 5-day treatment.
    [Abstract] [Full Text] [Related] [New Search]