Detection of chromogranins B and C from monocytes and microglia, and amphoterin-induced up-regulation of chromogranin B. Cells were adhered to amphoterin or fibronectin for 1 or 20 hours. mRNA was isolated and amplified in RT-PCR using primers specific for chromogranins B and C. (A) Amplified monocyte cDNA was analyzed using agarose gel electrophoresis and ethidium bromide staining. Bands of the expected size were obtained for both chromogranin B and C. +RT indicates reverse transcripted RNA; -RT, RNA without reverse transcription. (B) Amplified microglia cDNA from 1-hour fibronectin adherent or 20 hours of amphoterin or fibronectin-adherent microglia was analyzed. Bands specific for chromogranin B and C were detected in agarose gel electrophoresis. (C) Amphoterin induced chromogranin B up-regulation. Optical density of the RT-PCR bands was determined. Optical density of bands from cells adhering for 1 hour on fibronectin was defined as 1. Chromogranin B mRNA was strongly up-regulated in monocytes during 20 hours of adhesion to amphoterin but not to fibronectin. In addition, chromogranin B was up-regulated in amphoterin-adherent microglia. Chromogranin C mRNA was not up-regulated during adhesion. Results of RT-PCR are from 3 different experiments using monocytes from 3 different donors and from 4 different experiments using rat microglia from 4 different littermates. Bars represent ± SD.