ABSTRACT
<p><b>AIM</b>To explore the function state of protein tyrosine phosphatase (PTP) SHP-1 and CD45 under high partial pressure of oxygen (Po2) in lymphocyte.</p><p><b>METHODS</b>Primarily cultured rat splenic lymphocytes were treated with different pressure-duration of oxygen that led to promotion or inhibition of cell function. The catalytic activities, protein expression and tyrosine phosphorylation of SHP-1 and CD45 were determined.</p><p><b>RESULTS</b>The activity of SHP-1 was decreased after high Po2 treatment no matter what pressure-duration was, while the activity of CD45 was decreased only after high PoF that led to inhibition of lymphocyte function. The proteins expressed and tyrosine phosphorylation levels of two enzymes had no alteration in most treatment groups.</p><p><b>CONCLUSION</b>The decrease of PTP catalytic activities might be caused by their structures modification by high Po2 induced reactive oxygen species. SHP-1 and CD45 might be one of the key points of action through which high PO2 exerts its effects on lymphocytes.</p>
Subject(s)
Animals , Male , Rats , Cells, Cultured , Leukocyte Common Antigens , Metabolism , Lymphocytes , Metabolism , Oxygen , Metabolism , Partial Pressure , Phosphorylation , Protein Tyrosine Phosphatase, Non-Receptor Type 6 , Metabolism , Rats, Sprague-Dawley , Reactive Oxygen Species , MetabolismABSTRACT
<p><b>AIM</b>To investigate the preventive effects of Panax notoginseng saponins (PNS) and Ginkgo biloba extracts (GbE) on acute oxygen toxicity and the possible mechanisms.</p><p><b>METHODS</b>Mice were injected intraperitoneally with PNS and GbE for 5 days, then were exposed to 500 kPa hyperbaric oxygen (HBO) for 60 min, the convulsion latency, times and interval were observed. Moreover, reactive oxygen (RO) unit, MDA, NO, GSH levels and GSH-Px, CAT, MAO activities of mice brain were determined after they were exposed to HBO for 15 min.</p><p><b>RESULTS</b>PNS and GbE could markedly prolong the convulsion latency and interval, reduce convulsion times, decrease contents of MDA and NO in mice brain, keep RO unit, GSH and GSH-Px at higher levels, but had no effects on CAT and MAO activities.</p><p><b>CONCLUSION</b>PNS and GbE could effectively prevent acute oxygen toxicity, which were related to their antioxidant activities.</p>