Endothelin levels after extracorporeal shock waves, effects of renal function and blood pressure in rats

Abstract

Endothelin is a recently discovered peptide with strong vasoconstrictive effects which is of potential relevance in the development of renal hypertension and renal failure. It is secreted by endothelial cells in response to ischemia, endothelial lesions and inflammatory or traumatic processes. Endothelin level after extracorporeal shock waves, effects of renal function and blood pressure were examined in rats. Changes of plasma endothelin-1 (ET-1) levels after extracorporal shock waves were studied by applying 500 shock waves to both kidneys in Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Plasma ET-1 was measured before shock wave exposure and every thirty minutes up until 2 hours, then at 12 hours and 24 hours after shock wave exposure by specific sandwich enzyme immunoassay (EIA). Findings were then compared with those from the control group. Mean arterial pressure (MAP), glomerular filtration rate (GFR) and renal plasma flow (RPF) in rats were measured before shock wave exposure and every thirty minutes up until 2 hours after shock wave exposure, moreover made evaluation when ET-1 specific antibodies were administered intravenously into WKY and SHR. Plasma ET-1 was significantly increased in WKY (n = 6) and SHR (n = 7) after shock wave exposure as compared with that in the control group (p < 0.05). In SHR (n = 6), GFR temporarily decreased at 60 min but RPF remarkably decreased and renal vascular resistance (RVR) increased at 30 approximately 120 min after shock wave exposure (p < 0.05). However, infusion of ET-1 specific antibodies into SHR curbed change in those parameters, increased GFR and RPF at 60 approximately 120 min after shock wave exposure (p < 0.05). In WKY (n = 5), RPF temporarily decreased and RVR slightly increased, infusion of ET-1 specific antibodies curbed change in those parameters. MAP in SHR slightly increased at 30 min after shock wave exposure, but there was no significant change in WKY. These results suggest that plasma ET-1 levels elevated in both strains and ET-1 influenced renal function after extracorporeal shock waves, and that SHR is more sensitive to ET-1 in comparison with WKY.