The researchers studied the effects of long-term ketamine injections on rats' kidney and bladder tissues. They divided the rats into two groups, with one group receiving ketamine injections and the other receiving saline. After 2, 4, and 6 months, they measured urine volume, sodium and potassium levels, and kidney function. They found that rats injected with ketamine had increased urine volume and frequency, higher sodium levels, and lower potassium levels compared to the control group. The expression of H1 receptors in the kidneys and bladder was also significantly higher in the ketamine group.