Lupus-like syndrome is characterized by multiple organ injuries including lungs and kidneys. Endotoxin induces a transiently intent systemic inflammatory response and indirectly transient acute lung injury in normal condition. However, whether endotoxin may trigger the persistent development of lung injury in chronic, inflammatory lupus-like syndrome compared with normal condition remains unclear. We examined the pulmonary vascular permeability and production of proinflammatory cytokines, such as TNF-alpha, IL-6, IL-10 and IFN-gamma, which play prominent roles in the pathogenesis of lupus-like tissue injury, 6 h and 72 h after i.p. lipopolysaccharide (LPS; endotoxin) injection in pristane-primed chronic inflammation ICR mice characterized by a lupus-like syndrome. These results demonstrated that levels of serum IL-6, IL-10 and IFN-gamma and bronchoalveolar lavage (BAL) IL-6 and IFN-gamma were remarkably increased 6 h in LPS-exposed pristane-primed mice compared with pristane-primed controls, while pulmonary vascular permeability and levels of serum and BAL TNF-alpha were not. And levels of BAL TNF-alpha, IL-6 and IL-10 were significantly enhanced 72 h in LPS-exposed pristane-primed mice compared with pristane-primed controls. Also, LPS significantly induced the increased in vitro production of TNF-alpha, IL-6 and IL-10 by lung cells obtained from LPS-exposed pristane-primed mice compared with LPS-exposed normal mice. Our findings indicate that LPS may trigger persistent progression of lung injury through late overproduction of BAL TNF-alpha, IL-6, and IL-10 in lupus-like chronic inflammation syndrome compared with normal condition.