ABCA1 and ABCG1 mRNA stability enhanced by citrulline in macrophages. A, B, THP-1 macrophages were pretreated with 10 µg/ml of ActD 0.5 h before the treatment with control (Cont) or 1 mM of citrulline (Cit) with or without 10 µg/ml of ActD for 6 h. The results from 3 separately performed experiments are expressed relative to the vehicles and presented as the mean ± SEM. *Different from Cont or ActD, p<0.05, p<0.05. RNA extraction and quantitative real-time PCR were performed as described in Materials and Methods. C, D, THP-1 macrophages were pretreated with 10 µg/ml of ActD 0.5 h before the treatment with Cont or 1 mM of Cit with 10 µg/ml of ActD for 1, 3 and 6 h. The results from 3 separately performed experiments are expressed relative to the vehicles and presented as the mean ± SEM. *Different from Cont, p<0.05. RNA extraction and quantitative real-time PCR were performed as described in Materials and Methods.