Mycophenolic acid reduces renin-angiotensin-system activity in cultured mouse medullary thick ascending limb cells

Mai Szu Wu, Chih Wei Yang, Chiz Tzung Chang

Research output: Contribution to journalArticle

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Abstract

Mycophenolate mofetil (MMF) is a promising immunosuppressive agent. The intra-renal reninangiotensin system (RAS) plays an important role in the regulation of intra-renal hemodynamics. Mycophenolic acid (MPA) is the bioactive metabolite of MMF. The interaction between MPA and intra-renal RAS is still unclear. We hypothesized that MPA might affect intra-renal RAS activity. We chose models of cultured mouse medullary thick ascending limb (mTAL) cells for the experiments, as the mTAL is one of the major sites of intra-renal RAS. We investigated the angiotensin-converting enzyme (ACE) activity by means of enzymatic assay, and the angiotensin-receptor activity by means of a binding study with radiolabeled angiotensin II, and measured the intracellular calcium concentration in cultured cells treated with and without MPA. ACE activity changed neither in cells incubated with MPA nor in those treated without MPA. The binding study also indicated decreased angiotensin-II binding in MPA-treated (MPA 10 -7 M) cells, up to 43.7%. The decreased intracellular calcium concentration in MPA-treated cells further confirmed the MPA-inhibitory effect on the angiotensin receptor. We conclude that MPA reduces intra-renal RAS activity mainly through the decrease of AT1 receptor activity without affecting ACE activity. The results suggest that the inhibitory effect of MPA in the intra-renal RAS might play a role in the extra-immunosuppressive effect of MMF.

Original languageEnglish
Pages (from-to)655-659
Number of pages5
JournalTransplant International
Volume15
Issue number12
DOIs
Publication statusPublished - Dec 1 2002
Externally publishedYes

Fingerprint

Mycophenolic Acid
Renin-Angiotensin System
Extremities
Kidney
Peptidyl-Dipeptidase A
Angiotensin Receptors
Immunosuppressive Agents
Angiotensin II
Calcium
Enzyme Assays

Keywords

  • Angiotensin
  • Mycophenolate mofetil
  • Thick ascending limb cells

ASJC Scopus subject areas

  • Transplantation

Cite this

Mycophenolic acid reduces renin-angiotensin-system activity in cultured mouse medullary thick ascending limb cells. / Wu, Mai Szu; Yang, Chih Wei; Chang, Chiz Tzung.

In: Transplant International, Vol. 15, No. 12, 01.12.2002, p. 655-659.

Research output: Contribution to journalArticle

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