DIRECT MEASUREMENT OF NITRIC-OXIDE IN HEADSPACE GAS PRODUCED BY A CHICKEN MACROPHAGE CELL-LINE IN A CLOSED CULTURE SYSTEM

A simple and rapid method was applied for direct measurement of nitric oxide (NO) gas produced by cultured macrophages using a modified chemiluminescence detector, the thermal energy analyzer (TEA). HD 11 chicken macrophages (1-3 × 106/ml) were cultured on microcarrier beads (100 mg/ml) in 140 ml air-tight glass jars (5 ml cell suspension per jar) containing 0.5 μg/ml of LPS and different concentrations of l-arginine. Headspace gas was sampled at 24 hours of culture via a rubber septum and directly injected into a TEA with a liquid nitrogen trap set at -130 to -140°C. The concentration of NO in the gas sample was quantified using a standard gas mixture of NO (2 μl/L) in nitrogen. Gas samples from l-arginine-supplemented cultures contained NO (0.028 - 0.066 pl/μl), whereas NO was not detected in samples from controls. These results suggest that chicken macrophages synthesize NO gas in a dose-dependent manner relative to l-arginine concentration. © 1992.