Nitrogen recycling buffers against ammonia toxicity from skeletal muscle breakdown in hibernating arctic ground squirrels.

"Competing Interests: SR, AD, JR, SG, DS, CF, GT, and ND have no competing interests declared. KLD has a financial interest in Be Cool Pharmaceutics. RHC has a financial interest in Essential Blends, LLC. ZB has a financial interest in Barati Medical, LLC."

"Funding: Research reported in this publication was supported by NSF IOS 1258179 and by Institutional Development Awards (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant numbers 2P20GM103395 and P20GM130443. AD was supported by funds from the Boettcher Foundation Webb-Waring Early Career Award 2017, the National Institute of General Medical Sciences (RM1GM131968) and the National Heart, Lung and Blood Institute (R01HL146442 and R01HL148151). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health."