Abstract
-In rat glomeruli and mesangial cells, the thromboxane A 2 (TxA 2) mimetic, U-46,619, but not 8-iso-prostaglandin F 2α (8-isoPGF 2α), reduced glomerular inulin space and increased inositol 1,4,5-trisphosphate production, effects abolished by SQ29,548. In competitive binding studies using 8-iso-[ 3H]PGF 2α or [ 3H]SQ-29,548, mesangial cells displayed TxA 2 binding sites but not ones for 8-iso-PGF 2α. In contrast, rat aortic smooth muscle cells possessed specific binding sites for both TxA 2 and S-iso-PGF 2α and displayed functional responses to both agonists, such as time- and dose-dependent activation of mitogen-activated protein kinases. In these cells, the mean dissociation constant value for the isoprostane receptor was 31.8 ± 5.7 nM. When human TxA 2 receptor cDNA was expressed in Xenopus oocytes injected with the Ca 2+-specific photoprotein, aequorin, 8-iso-PGF 2α gave much weaker responses than U-46,619. These studies provide the first radio-ligand binding characteristics of the F 2-isoprostane receptor and demonstrate its specific and heterologous cellular localization. These studies support the distinct nature and biological significance of isoprostane receptors and provide a tool for their further molecular characterization.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Gastrointestinal and Liver Physiology |
| Volume | 272 |
| Issue number | 4 PART 2 |
| State | Published - 1997 |
| Externally published | Yes |
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Keywords
- Binding characteristics
- Mitogen-activated protein kinases
- Signal transduction mechanism
ASJC Scopus subject areas
- Physiology (medical)
Cite this
Evidence for the distinct nature of F 2-isoprostane receptors from those of thromboxane a 2 . / Fukunaga, Megumu; Yura, Takafumi; Grygorczyk, Ryszard; Badr, Kamal F.
In: American Journal of Physiology - Gastrointestinal and Liver Physiology, Vol. 272, No. 4 PART 2, 1997.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evidence for the distinct nature of F 2-isoprostane receptors from those of thromboxane a 2
AU - Fukunaga, Megumu
AU - Yura, Takafumi
AU - Grygorczyk, Ryszard
AU - Badr, Kamal F.
PY - 1997
Y1 - 1997
N2 - -In rat glomeruli and mesangial cells, the thromboxane A 2 (TxA 2) mimetic, U-46,619, but not 8-iso-prostaglandin F 2α (8-isoPGF 2α), reduced glomerular inulin space and increased inositol 1,4,5-trisphosphate production, effects abolished by SQ29,548. In competitive binding studies using 8-iso-[ 3H]PGF 2α or [ 3H]SQ-29,548, mesangial cells displayed TxA 2 binding sites but not ones for 8-iso-PGF 2α. In contrast, rat aortic smooth muscle cells possessed specific binding sites for both TxA 2 and S-iso-PGF 2α and displayed functional responses to both agonists, such as time- and dose-dependent activation of mitogen-activated protein kinases. In these cells, the mean dissociation constant value for the isoprostane receptor was 31.8 ± 5.7 nM. When human TxA 2 receptor cDNA was expressed in Xenopus oocytes injected with the Ca 2+-specific photoprotein, aequorin, 8-iso-PGF 2α gave much weaker responses than U-46,619. These studies provide the first radio-ligand binding characteristics of the F 2-isoprostane receptor and demonstrate its specific and heterologous cellular localization. These studies support the distinct nature and biological significance of isoprostane receptors and provide a tool for their further molecular characterization.
AB - -In rat glomeruli and mesangial cells, the thromboxane A 2 (TxA 2) mimetic, U-46,619, but not 8-iso-prostaglandin F 2α (8-isoPGF 2α), reduced glomerular inulin space and increased inositol 1,4,5-trisphosphate production, effects abolished by SQ29,548. In competitive binding studies using 8-iso-[ 3H]PGF 2α or [ 3H]SQ-29,548, mesangial cells displayed TxA 2 binding sites but not ones for 8-iso-PGF 2α. In contrast, rat aortic smooth muscle cells possessed specific binding sites for both TxA 2 and S-iso-PGF 2α and displayed functional responses to both agonists, such as time- and dose-dependent activation of mitogen-activated protein kinases. In these cells, the mean dissociation constant value for the isoprostane receptor was 31.8 ± 5.7 nM. When human TxA 2 receptor cDNA was expressed in Xenopus oocytes injected with the Ca 2+-specific photoprotein, aequorin, 8-iso-PGF 2α gave much weaker responses than U-46,619. These studies provide the first radio-ligand binding characteristics of the F 2-isoprostane receptor and demonstrate its specific and heterologous cellular localization. These studies support the distinct nature and biological significance of isoprostane receptors and provide a tool for their further molecular characterization.
KW - Binding characteristics
KW - Mitogen-activated protein kinases
KW - Signal transduction mechanism
UR - http://www.scopus.com/inward/record.url?scp=33745357020&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33745357020&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:33745357020
VL - 272
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0363-6135
IS - 4 PART 2
ER -