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

BACKGROUND: 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 (0micrometer, 30micrometer, 100micrometer, 300micrometer) 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 microgram/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 100micrometer and 300micrometer compared with the propofol-added or pretreated cells (P < 0.05). The stimulation index to LPS was lower at concentrations of 100micrometer and 300micrometer than at 30micrometer, and proliferative response of splenocytes were completely abrogated by adding toxic concentrations (100micrometer) 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.

Normal Lymphocyte Subpopulation of the Spleen is Altered after Peripheral Nerve Injury in Mice / 대한마취과학회지

BACKGROUND: Chronic neuropathic pain is often associated with altered immune function and the modulated immune cell response play a role in neuropathic pain by experimental nerve injury. In order to assess the possible changes in lymphocytes function following peripheral mononeuropathy, this study examined the lymphocyte subpopulation of the spleen using the monoclonal antibodies against the membrane surface markers in neuropathic BALB/c mice by a partial transection of sciatic nerve (PST). METHODS: After confirming tactile allodynia by paw withdrawal threshold, the splenic lymphocytes were stained with fluorescein isothiocyanate (FITC)-conjugated anti-mouse CD45R/B220 (B cell) and CD4 (helper/inducer T cell) or with phycoerythrin (PE)-conjugated anti-mouse CD90.2 (total T cell) and CD8 (suppressor/cytotoxic T cell). The proportions of subsets were analyzed using a FACScan laser flow cytometry system on postoperative day 5 and day 18 respectively. RESULTS: PST induced a mechanical allodynia as verified by the von Frey test at both 5 and 8 days postoperatively compared to pre-surgery (P < 0.05). Lymphocyte subpopulation was affected by PST. The proportion of CD4+ subset was significantly larger in the PST group than in the sham operated group on day 5, while the proportion of CD8+ subset was larger on day 18. In the PST group, there were significantchanges in the proportion of CD4+ on day 5 and in the proportion of CD8+ on day 18 (P < 0.05) compared to pre-surgery. There were no significant fluctuations in the proportion of total splenic T cell and B cell subsets of PST group compared to sham operated group. CONCLUSIONS: These results suggest that development of mononeuropathy is responsible for the proportional changes in splenic lymphocyte subsets in mice.

Alterations in NK Cell Cytotoxicity Induced by Peripheral Nerve Injury in Mice / 대한마취과학회지

BACKGROUND: Chronic pain is often associated with changes in the immune responses, which highlights the need for the aggressive pain control to obtain a better prognosis. This study examined splenic NK cell cytotoxicity in an attempt to assess the possible changes in the immune function under chronic neuropathic pain after a partial transsection of the sciatic nerve. METHODS: After confirming tactile allodynia in response to the von Frey filament, a modified lactate dehydrogenase (LDH) release assay was used to determine the cytotoxic activity of splenic NK cells on the YAC-1 cell line in C3H/HeN (H-2k) mice (n = 6). NK cells as effector cells were mixed with YAC-1 cells as target cells (1 x 10(4)/100microliter), resulting in an effector-target ratio of 1 : 25, 1 : 50, 1 : 100 in the culture medium. RESULTS: At 1 and 2 weeks after the nerve injury, all the subjects showed significant mechanical sensitivity compared with those observed before surgery. The percentage of NK cell cytotoxicity of the neuropathic mice increased significantly 1 week after the nerve injury but decreased within 2 weeks compared with the normal mice. CONCLUSIONS: In terms of the altered NK cell cytotoxicity, neuropathic pain can cause changes in the normal performance of the immune function.