Alteration in Baroreceptor Function in Rats Produces Typical Pressure Changes During Sleep: PDF OnlyPadilha Jose U.; Krieger, Eduardo M.Journal of Cardiovascular Pharmacology: 1987 - p S194-S198 Free Abstract Summary: We have shown previously that both sinoaortic denervation (SAD) and high renin hypertension in the rat produce a pronounced alteration in the pattern of pressure change during sleep, namely from unchanged to a rise in pressure during synchronized sleep (SS) and from a slight rise to a marked fall during desynchronized sleep (DS). Since acute SAD also produces overactivity of the reninangiotensin system (RAS), we investigated if this overactivity is essential for the development of the alterations. In rats studied 1 day after SAD (138 ± 1.0 mm Hg) the MAP rose during SS (+ 14 ± 0.7 vs. + 1.0 ± 0.16 mm Hg in the controls) and fell during DS (−27.2 ± 1.5 vs. + 4.9 ± 0.6 mm Hg in the controls). Captopril-treated rats, studied 1 day after SAD (89 ± 1.2 mm Hg), also exhibited rise in pressure during SS (+12.3 ± 0.6 mm Hg) and fall during DS (−12.8 ± 1.7 mm Hg). Similar alterations were observed in rats studied 10 days after SAD (116 ± 0.7 mm Hg) when RAS activity was normal (PRA: 1.3 ± 0.2 vs. 10.4 ± 2.7 ng AI/ml/h for SAD-1 day); the MAP rose during SS (+ 6.5 ± 0.3 mm Hg) and fell during DS (−5.0 ± 0.9 mm Hg). These data indicate that impairment of the baroreceptor function per se determines the typical alteration in the pattern of pressure change during sleep in the rat. Address correspondence and reprint requests to E. M. Krieger at Heart Institute (InCor), University Hospital, School of Medicine USP, P.O.B. 11.450, 05499, São Paulo, Brazil. © Lippincott-Raven Publishers.