Switching-on of serotonergic calcium signaling in activated hepatic stellate cells

Figure 2 5-hydroxytryptamine-induced intracellular Ca²⁺ concentration changes and the expression of 5-hydroxytryptamine₂ receptors in quiescent and activated hepatic stellate cells. A, B: 5-hydroxytryptamine (5-HT)-induced intracellular Ca²⁺ concentration ([Ca²⁺]_i) transients were recorded from hepatic stellate cells (HSCs) at 3 d (A) and 2 wk (B) after isolation; C: Averages of [Ca²⁺]_i changes (from 13-40 cells/each trace) in response to 5-HT (1-100 μmol/L) application to 2 wk-cultured HSCs are shown; D: Steady-state mRNA levels of the 5-HT receptor isotypes in 2 wk-cultured HSCs were compared using reverse transcription-polymerase chain reaction (RT-PCR); E: Using quantitative RT-PCR, the transcriptional changes in 5-HT₂ receptors among 1 d-, 1 wk- and 2 wk-cultured HSCs were compared. Expression levels were normalized to GAPDH and expressed as a relative expression ratio (target/GAPDH, n = 3). Data are presented as the mean ± SE.