Differential Effects on Acetaminophen-induced Nephrotoxicity and Liver Injury Following Modulation of Glutathione Resynthesis

Acetaminophen (APAP) overdose is a leading cause of acute liver failure (ALF), with acute kidney injury (AKI) increasing morbidity and mortality. N-acetylcysteine (NAC) prevents APAP-induced liver damage, but not AKI, highlighting the need to address differential inter-organ responses to APAP toxicity. We investigated the relationship between hepatic glutathione (GSH) depletion, liver injury, and subsequent kidney damage following APAP overdose. Male C57BL/6J mice received either moderate (300 mg/kg) or severe (600 mg/kg) overdoses of APAP, with or without buthionine sulfoximine (BSO, 50 mg/kg) to deplete GSH, or NAC (500 mg/kg) to replenish GSH. A moderate APAP overdose elevated liver injury markers (alanine aminotransferase, ALT) without significantly affecting blood urea nitrogen (BUN) levels, though kidney injury molecule-1 (KIM-1) expression increased. A severe overdose significantly increased ALT activities, and BUN and creatine levels, together with marked upregulation of renal KIM-1 and histological evidence of cortical damage. BSO exacerbated APAP-induced kidney but not liver injury, where GSH remained depleted at 24 hours. In contrast, NAC protected against APAP hepatotoxicity but not AKI. Thus, these findings demonstrate critical organ-specific responses to APAP toxicity and underscore the need for targeted therapeutic strategies specifically addressing APAP-induced kidney injury.