RESUMO
Objective To evaluate age-related changes of early plasma renal injury markers in rats with sepsis, which can serve as evidence for the early detection of acute kidney injury (AKI). Methods Twenty-one male Sprague Dawley rats were divided into 3 groups based on their age: young group(12 weeks, n=7), adult group (12 months, n=7), and old group (D-galactose-induced 12 months, 500 mg/(kg.d), for 6 weeks, n=7). All rats were received cecal ligation and puncture (CLP) procedure to induce sepsis. Plasma samples of each rat were collected 0.5 h before CLP, and 0.5 h, 4.5 h, 8.5 h after CLP. For each sample, plasma level of kidney injury markers, including plasma creatinine (Cr), blood urea nitrogen (BUN), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), interleukin-6 (IL-6), Cystatin C (CysC), insulin-like growth factor-binding protein 7 (IGFBP-7), tissue inhibitor of metalloproteinases-2 (TIMP-2) and [TIMP-2]*[IGFBP-7] were quantified. We adopted the criteria for AKI: plasma creatinine elevation =1.5 times of the baseline level. Within-group longitudinal changes and between-group changes were evaluated. Results Compared with samples collected at 0.5 h before CLP, plasma Cr levels were significantly increased at 0.5 h, 4.5 h and 8.5 h after CLP in all three groups (P0.05). Conclusion Only the young rats suffered earlier and more serious sepsis-induced AKI. Plasma level of Cr may be useful for early detection of sepsis. Age may not be a risk factor for early AKI in sepsis. Plasma TIMP-2, [TIMP-2]*[IGFBP-7] are potential markers for the detection of early AKI in sepsis in both young and adult animals.