title: Noise effects on the cochlear vasculature in normotensive and spontaneously hypertensive rats.
abstract: The cochlear vessels and the distribution of red blood corpuscles were studied in normotensive (N) and spontaneously hypertensive (SH) rats with and without noise exposure. The evaluation was made in a double blind manner. Ten N-rats and ten SH-rats were exposed to noise for 8 weeks and terminated immediately thereafter. The noise consisted of a 2 kHz broad noise band swept from 3 kHz to 30 kHz with a resultant equivalent sound level of 100 dB (lin) 10 h. Seven of 84 vascular parameters differed statistically at the 1% level between N- and SH-rats, and 8 and 10 parameters respectively differed for N- and SH-rats as a result of noise exposure. The observations were interpreted as indicative of a precapillary sphincter constriction in the radiating arterioles of the external wall with an upstream relative stasis and a downstream relative lack of blood, both in N- and SH-rats. In the spiral lamina the observations were interpreted as signs of a decreased blood flow after noise exposure, both in the N- and SH-animals, and most marked in the SH-animals after noise.
mesh_terms: D000818:Animals; D003051:Cochlea / Q000098:blood supply*; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000097:blood / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D006400:Hematocrit; D006973:Hypertension / Q000097:blood / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008833:Microcirculation / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow