L-Carnitine Ameliorates the Decrease of Aquaporin 2 Levels in Rats with Cisplatin-Induced Kidney Injury

Area of Science:

• Nephrology
• Pharmacology
• Biochemistry

Background:

• Cisplatin chemotherapy can cause acute kidney injury (AKI), impairing renal function.
• L-carnitine has shown potential in ameliorating cisplatin-induced AKI, but its specific role in urinary concentration defects is unclear.

Purpose of the Study:

• To investigate the detailed role of L-carnitine in improving renal urinary concentrating function in cisplatin-induced AKI.
• To elucidate the molecular mechanisms by which L-carnitine exerts its protective effects on kidney function.

Main Methods:

• 30 Sprague-Dawley rats were divided into control, cisplatin, L-carnitine, and combined treatment groups.
• Renal urinary concentrating function was assessed via urine and blood sample analysis.
• Aquaporin-2 (AQP2) levels and localization, along with upstream signaling proteins (GSα protein, AVP receptor 2, adenylyl cyclase, serum AVP), were evaluated using immunoblotting, confocal microscopy, and ELISA.

Main Results:

• L-carnitine administration significantly improved renal urinary concentrating function in cisplatin-induced AKI rats.
• Cisplatin-induced reduction in AQP2 expression was reversed by L-carnitine, with increased AQP2 accumulation in renal-collecting ducts.
• L-carnitine enhanced the expression of key AQP2 upstream signaling proteins, including GSα protein, adenylyl cyclase, and serum AVP levels.

Conclusions:

• L-carnitine effectively resolves cisplatin-induced urinary concentration defects in rats.
• The mechanism involves increasing arginine vasopressin (AVP)/cyclic adenosine monophosphate (cAMP)/AQP2 levels.
• L-carnitine holds potential for ameliorating renal urinary concentration issues in cancer patients undergoing cisplatin treatment.