Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment.

Aim: To study the effect of carbon dioxide (CO) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations.

Patients And Methods: Forty-seven hypertensive patients who underwent transcutaneous CO therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO treatment. Controls did not undergo CO treatment. Plasma ADMA levels were measured by ELISA.

Results: ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019).

Conclusion: The short- and long-term decrease of ADMA levels suggests that CO is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO treatment.