Chronic restraint stress aggravated arthritic joint swell of rats through regulating nitric oxide production.

Stress-related hormone norepinephrine (NE) displayed diverse effects on immune system including macrophages, which influenced many kinds of inflammatory diseases. Nitric oxide (NO) from activated macrophages played an important role in inflammatory diseases. In this study, we investigated under chronic restraint stress how NE influenced the joint swell of Complete Freund's Adjuvant (CFA)-induced arthritis of rats and whether NE regulated macrophage's production of NO through influencing phosphorylation of protein kinases C (PKC).