Figure 1.

Phospholipase D (PLD) activity is stimulated by phenylephrine (PHE) and PMA in rat-1 fibroblasts. Cells in serum-free DMEM were incubated overnight with 1 μCi/ml [³H]oleic acid, pretreated with 200 mM ethanol (A, B) or with or without ethanol (C) for the measurement of phosphatidylethanol (PEt) formation, and finally treated with different concentration of PHE (A, basal = 7.09 ± 2.68 × 10³ × [³H]PEt / [³H]total lipids) or PMA (B, basal = 6.81 ± 2.07 × 10³ × [³H]PEt / [³H]total lipids) for 15 min. Data are expressed as the ratio of [³H]PEt over [³H]total lipids. Values are the mean ± S.E. of three independent experiments performed in duplicate. * Value significantly different from vehicle, p < .05.