The Inhibitory Effect of Propofol on Splenocytes Proliferations to Lipopolysaccharide in BALB/c Mice: Based on the Measurement of BrdU Incorporationin vitro

Abstract

Anesthetics have been suspected of impairing various aspects of the immune function either directly by affecting the function of immunocompetent cells or indirectly by modulating the stress response. Splenocytes play important roles in the cellular host defense against infection. In order to assess the immune modulatory effects of propofol, this study examined the cytotoxic and proliferative effects of propofol on splenocytes. Methods: Splenocytes, as responders, were isolated from BALB/c mice (n = 10). The cells were pretreated with different propofol concentrations (0μM, 30μM, 100μM, 300μM) for 24 hours. The cytotoxic effect was assayed by the NADH dehydrogenase activity and the proliferation was evaluated by the level of 5-bromo-2’-deoxyunridine (BrdU) incorporation during DNA synthesis in the presence or absence of propofol, in addition to lipopolysaccharide (LPS, 1 μg/ml) for mitogenic stimulation. A cell proliferation enzyme-linked immuno-sorbent assay (ELISA) system was used, and the stimulation index was calculated in the presence or absence of propofol. Results: The percentage of the NADH dehydrogenase activity was changed by the propofol pretreatment (P ＜ 0.001). LPS stimulation significantly decreased the NADH dehydrogenase activity at 100μM and 300μM compared with the propofol-added or pretreated cells (P ＜ 0.05). The stimulation index to LPS was lower at concentrations of 100μM and 300μM than at 30μM, and proliferative response of splenocytes were completely abrogated by adding toxic concentrations (100μM) of propofol (P ＜ 0.05). Conclusions: Neither cytotoxicity, as defined by the NADH dehydrogenase activity, nor a proliferative effect, as measured by the level of (BrdU) incorporation in the splenocytes, were affected by the clinical concentration of propofol.