EXTRACORPOREAL SHOCK-WAVE LITHOTRIPSY INDUCES THE RELEASE OF PROSTAGLANDINS WHICH INCREASE URETERAL PERISTALSIS

The aim of this study was to identify the changes in secretion of pros taglandins into the urinary tract as a result of treatment by extracor poreal shock wave lithotripsy (ESWL) and to determine their effects on ureteric motility. Sixteen patients with renal or upper ureteric calc uli were studied. A peripheral blood and urine sample was collected im mediately before and after ESWL, with further samples taken 24 h later . The following variables were assessed by radioimmunoassay: prostagla ndin E2 (PGE2), prostaglandin F1alpha (PGF1alpha), and thromboxane B2 (TXB2). An in vitro canine study was then designed to study the activi ty of TXB2, PGF1alpha and PGE2 on an isolated intact canine ureter mod el. Significant elevations of TXB2 were found immediately after ESWL i n both serum and urine, which fell almost to pre-treatment levels by 2 4 h. PGF1alpha levels showed significant elevations at 24 h but no imm ediate increase as seen with TXB2. In contrast, PGE2 levels were uncha nged in the urine but significantly decreased in the serum. In vitro s tudies showed that both TXB2 and PGF1alpha repeatedly produced an incr eased frequency of ureteric contraction. ESWL results in the release o f prostaglandins from the urinary tract which are shown to cause incre ased ureteric peristalsis.