I stat1 handheld analyzer

Animals were anesthetized by intraperitoneal injection with 100 mg/kg ketamine and 10 mg/kg xylazine. Once an animal was unconscious, the kidneys were removed, and the cortex and medulla were separated by free-hand dissection and flash-frozen in liquid nitrogen. Blood samples were collected from the carotid artery. Blood chemistry (Na⁺, K⁺, Cl^–, HCO₃^–, pH, hematocrit, and BUN) were measured using a 100 μL aliquot of whole blood using an i-STAT EC8+ cartridge and an i-STAT1 Handheld Analyzer (Abaxis). The remaining fraction of blood was immediately spun down, and plasma was frozen.

Mice were acclimated to metabolic cages (Nalgene) for 3 days prior to experimental manipulation. Urine output, food and water intake was monitored and measured daily. For tissue and blood collection, mice were anesthetized by intraperitoneal injection with ketamine-xylazine (100 mg/kg ketamine and 10 mg/kg xylazine). Blood samples were collected from the right carotid artery using a 1,000 μl pipette tip containing heparin and evaluated immediately for electrolyte analysis. Blood chemistry and gases (Na⁺, K⁺, Cl⁻, HCO₃⁻, pH, hematocrit, and BUN) were measured using a 100 μl aliquot of whole blood using an i-STAT EC3 or EC8+ cartridge and i-STAT1 Handheld Analyzer (Abaxis). Remaining blood was immediately spun down to separate the plasma and frozen for later analysis. Urine was collected daily in 24-h increments and immediately stored at −80°C for later analysis of K⁺, Na⁺, and Cl⁻ excretion (CareLyte Chemistry Analyzer, Diamond Diagnostics) or measuring PGE2 levels. Although there were no differences in food consumption across all treatment groups, individual variability within groups was noted. To account for this, electrolyte excretion data were individually normalized to dietary intake. Plasma and urine osmolarity were measured using a vapor pressure osmometer (Wescor-Vapro 5520).