Ulinastatin Alleviates Neuroinflammation but Fails to Improve Cognitive Function in Aged Rats Following Partial Hepatectomy

Postoperative cognitive dysfunction (POCD) is very common complication of surgery in aged individuals. Accumulated evidence suggests that neuroinflammation may be the underlying cause of POCD. The aim of the present study was to investigate the effects of ulinastatin (UTI) on neuroinflammation and on learning and memory of aged rats after anesthesia and surgery. Our results showed that anesthetic isoflurane increased the hippocampal mRNA level of IL-1 beta, while surgery of partial hepatectomy increased the hippocampal mRNA levels of IL-1 beta, TNF-alpha, and IL-6 as well as impaired rats' spatial memory at day 7 post-surgery. UTI (10,000 U/kg, i.v.) decreased the anesthesia- and surgery-induced increases in mRNA levels of all three cytokines, but did not improve the rats' impaired working memory. In conclusion, moderate and temporary suppression of UTI-induced inflammatory cytokines in hippocampus is not sufficient to alleviate the impairment of working memory.