Angiotensin receptor type 1 blockade in astroglia decreases hypoxia-induced cell damage and TNF alpha release

Neurochem Res. 2007 Sep;32(9):1489-98. doi: 10.1007/s11064-007-9337-6. Epub 2007 Apr 4.

Abstract

The present study investigated the role of angiotensin receptors (AT-R) in the survival and inflammatory response of astroglia upon hypoxic injury. Exposure of rat astroglial primary cultures (APC) to hypoxic conditions (HC) led to decreased viability of the cells and to a 3.5-fold increase in TNF-alpha release. AT-R type1 (AT1-R) antagonist losartan and its metabolite EXP3174 decrease the LDH release (by 36 +/- 9%; 45 +/- 6%) from APC under HC. Losartan diminished TNF-alpha release (by 40 +/- 15%) and the number of TUNEL-cells by 204 +/- 38% under HC, alone and together with angiotensin II (ATII), while EXP3174 was dependent on ATII for its effect on TNF-alpha. The AT2-R antagonist, PD123.319, did not influence the release of LDH and TNF-alpha under normoxic (NC) and HC. These data suggest that AT1-R may decrease the susceptibility of astrocytes to hypoxic injury and their propensity to release TNF-alpha. AT1-R antagonists may therefore be of therapeutic value during hypoxia-associated neurodegeneration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / drug effects*
  • Astrocytes / metabolism*
  • Cell Hypoxia / physiology*
  • Cells, Cultured
  • Imidazoles / pharmacology
  • Losartan / pharmacology*
  • Rats
  • Rats, Wistar
  • Receptor, Angiotensin, Type 1 / biosynthesis
  • Receptor, Angiotensin, Type 1 / drug effects*
  • Receptor, Angiotensin, Type 2 / biosynthesis
  • Tetrazoles / pharmacology
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Imidazoles
  • Receptor, Angiotensin, Type 1
  • Receptor, Angiotensin, Type 2
  • Tetrazoles
  • Tumor Necrosis Factor-alpha
  • losartan carboxylic acid
  • Losartan