Correlation between trypsin binding to a specific receptor and prostacyclin production in cultured vascular endothelial cells
✍ Scribed by Naphtali Savion; Nava Naveh-Floman
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 642 KB
- Volume
- 122
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
✦ Synopsis
The correlation between the binding and processing of trypsin and its effect on prostacyclin (PCI2) production in cultured adult bovine aortic endothelial (ABAE) cells was studied. ABAE cells demonstrated an ability to produce PG12 in a dose-response manner to trypsin at the range of 0.1-2.0 p g h l with a saturation at a concentration of 1 pg/rnl. Likewise, 1251-trypsin binding to the cultured cells increased in a dose-response way and reached saturation at a concentration of about 1 pglml; '251-trypsin was bound to a specific hi h and each of the confluent ABAE cells has about 1.2 x lo5 such receptors sites. The cell-surface receptor for trypsin displayed specific characteristics and an excess amount of unlabeled trypsin successfully abolished 1251-trypsin binding while thrombin in excess failed to compete for 1251-trypsin binding. Only a small fraction of the cell-surface-bound '251-trypsin was internalized and subsequently degraded by ABAE cells as compared to the process of 1251trypsin internalization by human skin fibroblasts (HSF). This study demonstrated that the stimulatory effect of trypsin on prostacyclin production and release by ABAE cells might be mediated by a specific cell-surface receptor for trypsin on these cells distinct from the thrombin receptor. affinity cell-surface receptor with a dissociation constant (Kd) of 1.5 x 10-I F -M