At completion of the accumulation period, the transport medium was removed by aspiration and accumulation was terminated by adding ice cold EBSS. Cells were solubilized for 30 minutes with 1 N NaOH and then transferred to scintillation vials con taining 2 N HCl and scintillation cocktail. Cellular incorporation of the radiolabeled probe was measured using MK-8745? liquid scintilla tion counting. The sample counts in each well were standardized to the amount of cell protein present, as determined by the Bradford colorimetric method with BSA as the standard. Nitrite measurement Nitric oxide production and release by primary cultures of microglia and HAPI cells were determined by meas urement of nitrite levels using a colorimetric method with Griess reagent as described previously.

Briefly, cells were seeded in 24 multiwell plates and incubated with and without LPS andor various Inhibitors,Modulators,Libraries signal pathway inhibitors activators for 24 hours. At the end of the incubation period, culture supernatants were mixed with equal volumes of Griess reagent, incubated in the dark for 10 minutes and the absorbance was measured with a UV MAX kinetic microplate reader. The absolute nitrite con centrations were determined from an eight point sodium nitrite standard curve. The lower limit of detection of the assay was approximately 1. 5 uM. TNF determination Cells were seeded in 24 multiwell plates and incubated with and without LPS andor various signal pathway in hibitorsactivators for 24 hours.

At the end of the incu bation period, the production and release of TNF into the culture medium by primary cultures of microglia or HAPI cells was measured with a commercially available enzyme linked immunosorbent assay kit from R D Systems, according to the manufacturers instructions. The absorbance was measured with a UV MAX kinetic microplate Inhibitors,Modulators,Libraries reader, using a 570 nm wavelength correction. RT PCR analysis RNA expression of several transporters was measured by reverse transcriptase polymerase chain reaction. Inhibitors,Modulators,Libraries RNA from microglia was dried down, and resuspended in 5 uL of RNAse free water. The RNA was reverse transcribed from an oligo dT pri mer using Omniscript according to the manufacturers instructions. Following Inhibitors,Modulators,Libraries reverse transcription, 1. 5 uL of the 20 uL reaction was used in a polymerase chain reaction, 0. 2 mM dNTPs, 0. 25 uM each primer, 0. 25 uL Taq polymerase. Cycling parameters were one cycle at 95 C for five minutes, followed by 35 cycles of 94 C, 55 C, 72 C, and a final extension at 72 C for seven minutes. RT PCR products were analyzed by agarose gel electrophoresis. GAPDH was used as an endogenous Inhibitors,Modulators,Libraries control. Primers for GAPDH were acquired from PE Applied Biosystems. Immunoblotting Crude membrane proteins were obtained from treated and untreated selleck chemicals Ivacaftor HAPI microglia.