Stimulation of Na+/H+exchange activity by endothelin in opossum kidney cells

✍ Scribed by R. Walter; C. Helmle-Kolb; J. Forgo; U. Binswanger; H. Murer

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 931 KB
• Volume: 430
• Category: Article
• ISSN: 0031-6768
• DOI: 10.1007/bf00373849

✦ Synopsis

Endothelin-1 (ET-1) controls multiple aspects of kidney function. In this study we have analysed the effects of ET-1 on apical Na+/H + exchange activity in opossum kidney (OK) cells. ET-1 (at 10-1~ and 10-SM) activated Na+/H + exchange activity within 5 min of exposure. ET-1 (10 -8 M) prevented PTHinduced (parathyroid hormone; 10 8 M) inhibition of Na+/H + exchange activity; it also abolished transport inhibition in response to 10-3M IBMX (isobutylmethylxanthine) and 3 x 10-7M TPA (phorbol 12myristate 13-acetate), but had no effect on the 8-bromo-cAMP-induced (104M) decrease of transport rate. Basal cAMP content, IBMX-and PTH-stimulated cAMP production were unaffected by ET-1 (10 .8 M). The stimulatory action of ET-1 (10 -8 M) on Na+/H + exchange activity was prevented by calphostin C (10 8 M). These data document that OK cells might serve as a useful in vitro model for analysis of cellular mechanisms involved in endothelin action; proteine kinase C activation seems to participate in the observed endothelin effects.