Figure 1.

Regulation of AQP1 expression in 9L cells. 9L gliosarcoma cells were cultured as described in the Materials and Methods section. Total RNA was harvested from cells exposed to the indicated condition for 24 hours. The concentration of the agent added to the culture medium is indicated above the appropriate lane. The amounts added equal the final concentration in the medium, except for NaCl. NaCl was added to the medium already containing a normal concentration of 110 mM. Standard DME was used, except for experiments examining the effect of glucose, in which case glucose was added to glucose-free medium to achieve the indicated final concentration. Levels of AQP1 transcripts were determined by RT-PCR using primers specific for rat AQP1. Glyceraldehyde-3-phosphate-dehydrogenase was used as a housekeeping gene. All of these conditions induced the expression of AQP1 in these cells. Experiments were duplicated in independent cultures. Dex, dexamethasone.