Evaluation of differential effects of CDP-choline and choline on parasympathetic activity and changes in choline levels with heart rate variability

Objective: Heart rate variability (HRV) is used to evaluate the autonomic activity of heartbeat. This study aimed to investigate the effects of cholinomimetic drugs cytidine diphosphate-choline (CDP-choline) and choline, on short-term HRV parameters. Materials and Methods: Animals were randomized into three groups; control (0.9% NaCl), choline (100 mg/kg), CDP-choline (400 mg/kg). Electrocardiography recordings were obtained for 45-minutes after treatments with 15-minutes intervals. HRV analyses and total choline level measurements in serum and heart tissues were performed. Results: High frequency power and total power increased in treatment groups, while heart rates were decreased. Low frequency was decreased with choline while very low frequency power decreased with CDP-choline. Choline affected most of the HRV parameters in the first 15 minutes, while the effect of CDP-choline started within 30 minutes. Total choline levels were higher in both treatment groups than in the control while the levels were also higher in the choline group compared to CDP-choline group. Conclusion: This study showed that CDP-choline and choline treatments produced a rapid response to short-term HRV parameters, while increasing tissue choline levels. Moreover, the differences in effects and onset time between the drugs on HRV might be related to tissue choline concentration.