EFFECT OF 8-(N,N′-DIETHYLAMINO)-n-OCTYL-3,4,5-TRIMETHOXYBENZOATE ON Ca²⁺i AND THE RELEASE OF NO IN CULTURED ENDOTHELIAL CELLS OF THE CALF MIDDLE CEREBRAL ARTERY

The effect of 8-(N,N′-diethylamino)-n-octyl-3,4,5-trimethoxybenzoate(TMB-8) on Ca²⁺i and the release of NO in cultured endothelial cells of the calf middle cerebral artery was studied by a system of measurement of ARCM-MIC, using Fura-2/AM as a fluoresent indicator and the oxyhaemoglobin method. In the presence of extracellular Ca²⁺ 1.3 mmol·L^-1, the resting Ca²⁺i and the extinction difference(ΔE) of between 401 and 410 nm were not changed by TMB-8 12.5 and 25 μmol·L^-1, but were increased by TMB-8 50 and 100 μmol·L^-1. The rise of ΔE induced by TMB-8 50 and 100 μmol·L^-1 was blocked completely by L-NAME. The elevation of Ca²⁺i was related to the release of NO. The result suggested that TMB-8 increased resting Ca²⁺i of endothelial cells of the calf middle cerebral artery and induced NO release.