Ketamine treatment increases aldh2 mRNA expression in WT mice and increases urination frequency and reduces body weight in KO mice. (A) Reverse transcription-quantitative PCR was performed to measure the mRNA expression of aldh2 in WT mice at 4 and 8 weeks following saline and ketamine treatment. (B) Changes in urination frequency of KO and WT mice during 4-, 8- and 12-week ketamine treatments. (C) Weekly weight changes of KO and WT mice (each week, group WT vs. group KO). Data were presented as the mean ± standard error of the mean from ≥3 experimental repeats. *P<0.05 and **P<0.01. Aldh2, aldehyde dehydrogenase 2; WT, wild-type; KO, knock-out; WNS, wild-type normal saline control group; WLK, wild-type low-dose ketamine group; WHK, wild-type high-dose ketamine group; KNS, knock-out normal saline control group; KLK, knock-out low-dose ketamine group; KHK, knock-out high-dose ketamine group; NS, normal saline; LK, low-dose ketamine; HK, high-dose ketamine; w, week.