Endotoxemia in Rats with NMDA Modulation

Rats received an intraperitoneal injection of LPS (4 mg kg^-1; Escherichia coli serotype 055:B5; Sigma-Aldrich, St. Louis, MO) to induce endotoxemia, as previously described [18 (link)]. These rats were termed the “LPS group”. Control groups received identical volumes of phosphate-buffered saline (PBS, pH 7.4). Basic body data and hemodynamic parameters were evaluated at 8, 24, and 48 h post-LPS injection. To examine the role of NMDA receptors, MK-801 (Sigma-Aldrich) was co-administered to LPS-treated (the LPS+MK-801 group) and PBS-treated (the MK-801 group) rats (0.3 mg kg^-1 via subcutaneous injection), as previously described [19 (link)]. This dose did not produce obvious side effects, such as behavioral changes [19 (link)], and the final concentration in treated animals was comparable with that reported in a previous study [20 (link)].