PCNA content in TM3 cells is increased by GABA and GABAA agonist isoguvacine. Using Western blot analyses we examined PCNA content of TM3 cells after 0, 5, 10, 15, 30 min stimulation with GABA, GABA+bicuculline, isoguvacine and isoguvacine+bicuculline, respectively. The PCNA content of TM3 cells after 15 min stimulation with GABA (A) is significantly higher compared to untreated TM3 cells or compared to TM3 cells stimulated for 15 min with GABA+bicuculline. After 15 min stimulation with isoguvacine (B) the PCNA content of TM3 cells is also significantly higher compared to untreated TM3 cells or compared to TM3 cells stimulated for 15 min with isoguvacine+bicuculline. Data represent means+SEMs of n = 5 independent experiments and were normalized to β-Actin levels. Columns with different superscripts are significantly (p < 0.001, ANOVA/Dunnett's test) different from each other. Figure 7C and 7D depict representative Western blot experiments, respectively.