NOISE-INDUCED ELEVATIONS OF PLASMA ENDOTHELIN (ET-3)

The endothelins (ETs) are a novel family of peptides which participate in hemodynamic homeostasis. Elevated levels of circulating ETs are ev ident in several stress related conditions and are associated with a v ariety of vascular pathophysiologies. The purpose of the current study was to test the possibility that plasma concentrations of endothelin increase following noise exposure- using radioimmunoassay (RIA). No di fference in plasma endothelin was detected in rats subjected to brief noise exposure (30 min of 100 dB SPL broad-band noise) compared to con trol animals. Statistically significant elevations in plasma endotheli n (ET-3) were measured in animals exposed to prolonged noise exposure (90 min and 72 h of 100 dB SPL broad-band noise). These results sugges t that hemodynamic alterations, and potential vascular pathophysiologi es accompanying prolonged exposure to noise are mediated by endothelin .