Sound-withdrawal hypertension in rats—a new form of experimental hypertension

Abstract

Abstract Females of an inbred strain of Wistar rats, initially 160–180 g, develop hypertension when transferred from the stock (normal rat) room (NRR) to a sound-proofed semi-anechoic room (SPR). No hypertension develops when sounds in the NRR are relayed unchanged into the SPR. The hypertension reaches maximum at 4 weeks then decreases slightly to stabilize at a level approximately 30 mm Hg above normal before, and 20 mm Hg above normal after, pentolinium blockade. Histological changes are demonstrable in small arteries after 12 weeks in the SPR. Augmented pressor responses to fixed doses of noradrenaline and of tyramine, but not of angiotensin II and of vasopressin, and a general increase in organ/body wt ratios were evident in weeks 3–5 after entry to the SPR, but had reversed by week 12. These findings contrast with those made on salt-DOCA hypertensives.