Abstract:Objective To investigate the role of neutrophil gelatinase-associated lipocalin (NGAL) in secondary brain injury after intracerebral hemorrhage (ICH).Methods Type VII collagenase was used to establish the model of ICH. A total of 90 male Sprague-Dawley rats were randomly divided into normal control group (10 rats), sham-operation group (40 rats), and ICH model group (40 rats). The neurologic impairment score was obtained at 6, 24, and 72 hours and 7 days after ICH, and immunohistochemistry and RT-qPCR were used to measure the expression of NGAL and matrix metallopeptidase-9 (MMP-9) in brain tissue at different time points.Results The results of immunohistochemistry and RT-qPCR showed that the model group had a large number of cells with the expression of NGAL and MMP-9, as well as the mRNA expression of NGAL, which were significantly higher than those of the normal control group and sham-operation group (P<0.05). In the ICH model group, the protein expression of NGAL was positively correlated with that of MMP-9 (P<0.01), and the protein expression of NGAL and MMP-9 was also positively correlated with neurologic impairment score in rats (P<0.05).Conclusions There is increased expression of NGAL after ICH, which suggests that NGAL may be involved in secondary brain injury after ICH. NGAL may regulate the activity of MMP-9, but further studies are needed to determine whether NGAL is the upstream regulatory factor of MMP-9.