Effects of extracorporeal shock wave lithotripsy on plasma levels of nitric oxide and cyclic nucleotides in human subjects

Purpose: The role of extracorporeal shock wave lithotripsy (ESWL, Dornier Medizintechnik GmbH, Wessling Munchen, Germany) on plasma nitric oxide (NO) and cyclic nucleotides was investigated. It is known that ESWL increased plasma levels of vasoactive substances. Materials and Methods: A total of 28 patients undergoing ESWL for renal (14) and lower ureteral (14) stones participated in a prospective study. Peripheral blood samples were analyzed for plasma nitrite, NO metabolite, cyclic 3',5'-guanosine monophosphate (cGMP), cyclic 3',5'-adenosine monophosphate and plasma renin activity before, immediately after, 30 and 60 minutes after ESWL. Urine samples were also analyzed for nitrite before, immediately after, 30 and 60 minutes after ESWL. Blood pressure and pulse rate were measured before and after ESWL. Results: ESWL increased mean plasma nitrite levels. Before, immediately after, 30 and 60 minutes after ESWL mean plasma nitrate plus or minus standard error in patients with renal versus lower ureteral stones was 43.6 +/- 8.5, 52.8 +/- 7.4, 54.0 +/- 8.0 and 52.2 +/- 9.1 versus 27 +/- 5.8, 24.6 +/- 4.7, 23.6 +/- 4.8 and 28.0 +/- 7.1 nM., respectively. Before, immediately after, 30 and 60 minutes after ESWL mean plasma cGMP in patients with renal versus lower ureteral stones was 1.21 +/- 0.1, 1.64 +/- 0.16, 1.52 +/- 0.12 and 1.58 +/- 0.14 versus 1.45 +/- 0.18, 1.52 +/- 0.13, 1.52 +/- 0.15 and 1.51 +/- 0.11 fmol., respectively. Cyclic 3',5'-adenosine monophosphate was not increased by ESWL in patients with renal stones. Urine nitrite increased slightly but not significantly after ESWL. Plasma cyclic nucleotides and nitrite, and urine nitrite were not changed by ESWL in patients with lower ureteral stones. Plasma renin activity decreased significantly in patients with renal stones 60 minutes after ESWL. Blood pressure and pulse rates increased mildly without statistical significance after ESWL for renal stones. Conclusions: ESWL increases plasma nitrite and cGMP in patients with renal stones, suggesting that shock waves stimulate the NO-cGMP signaling pathway.