Actions of endothelin-1 on cultured rat renomedullary interstitial cells are modulated by nitric oxide

Abstract

1. Cultured renomedullary interstitial cells (RMIC) isolated from 4- week-old Sprague-Dawley rat kidneys possess ET(A) receptors, as identified by reverse transcription-polymerase chain reaction (RT-PCR). 2. Treatment with endothelin (ET)-1 (10-6 mol/L) increases the intracellular inositol 1,4,5- trisphosphate concentrations within 10 s and intracellular calcium concentrations after 7 s. 3. Endothelin-1 (10-7 and 10-10 mol/L) induced increases in intracellular cAMP concentrations, but only in the presence of N(ω)-nitro-L-arginine, a nitric oxide synthase (NOS) inhibitor. Addition of ET-1 (10-10 mol/L) to the RMIC culture led to increases in intracellular cGMP concentrations through activatio..