Multiple organ dysfunction syndrome (
MODS) in the elderly is the most common cause of mortality in
critically ill elderly patients, and it is different from
MODS in the adult in clinic. Rare studies have been done on its pathogenesis and the comparison between adult and elderly
MODS animal models. This work aimed at exploring the mechanisms mediating elderly
MODS and compared this with adult
MODS. Male Sprague-Dawley aged and adult rats were intraperitoneally injected with
zymosan for incitement of
MODS. Aged rats receiving
zymosan showed severer pulmonary, cardiac and renal dysfunctions than adult rats. Likewise, the tissue lesions under light microscope in major organs of
zymosan treated aged rats were much worse than those of
zymosan treated adult rats. Moreover,
zymosan treated aged rats showed 142% and 64% greater increase in pulmonary alveolar macrophages (AMs) apoptotic rate and serum
TNF-alpha level, respectively, whereas 43% smaller increase in serum
IL-10 level compared to
zymosan treated adult rats. Furthermore,
lung injury was much worse than that in other organs in
zymosan treated aged rats. Overall, these results suggest that
zymosan can be used in aged rats to incite
MODS in the elderly. In the animal model of elderly
MODS, there are (1) severer injury in lung, heart and kidney vs adult; (2) easier to develop severe
systemic inflammatory response syndrome (SIRS) instead of compensatory anti-inflammatory response syndrome (CARS) compared to the adult; and (3) severer
inflammation in lung than other organs indicative of the possible roles of lung in triggering
MODS in the elderly.