The Preventive Effect of Ulinastatin on Blood–Brain Barrier Dysfunction in Rats with Postoperative Cognitive Dysfunction After General Anaesthesia with Isoflurane

This study evaluated the effect of ulinastatin on blood-brain barrier (BBB) dysfunction in rats with postoperative cognitive dysfunction (POCD) following general anaesthesia with isoflurane. Specifically, we examined BBB permeability and the expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1). Rats in the ulinastatin group received the drug intraperitoneally (50,000 U/mL), while controls received normal saline (1 mL) administered before general anaesthesia. Isoflurane (1.5% volume) anaesthesia was induced for 2 h. Cognitive function was assessed using the Y-maze test. Two days after anaesthesia, BBB permeability was measured using Evans blue, and TIMP-1 expression was evaluated. Both groups experienced cognitive decline following anaesthesia. However, the ulinastatin group showed a more limited decrease (control group, 64.2 ± 19.3 → 30.2 ± 16.2,