Sympathetic and angiotensinergic responses mediated by paradoxical sleep loss in rats

Introduction: Recent investigations over the past decade have linked the development of hypertension to sleep loss, although the mechanisms underlying this association are still under scrutiny. To determine the relationship between sleep deprivation and cardiovascular dysfunction, we examined the effects of paradoxical sleep deprivation on heart rate, blood pressure, sympathetic nerve activity (SNA) and their consequences in the blood renin-angiotensin system.Materials and methods: Wistar-Hannover male rats were randomly assigned to three experimental groups: 1) control, 2) paradoxical sleep deprivation for 24 h and 3) paradoxical sleep deprivation for 96 h. Blood pressure and heart rate were recorded in awake, freely moving rats.Results: Heart rate was higher in the 96 h paradoxical sleep deprivation group compared with the control group. Renal SNA was increased in all deprived groups. However, no significant statistical differences were observed in blood pressure or splanchnic SNA among groups. Paradoxical sleep deprivation (24 and 96 h) reduced plasma angiotensin II (Ang II) concentrations.Conclusions: the results suggest that selective sleep deprivation produces an increase in SNA, preferentially in the kidney. Thus, alterations in the sympathetic system in response to sleep loss may be an important pathway through which hypertension develops.Associacao Fundo de Incentivo a Psicofarmacologia (AFIP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Psychobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, BR-04024002 São Paulo, BrazilUniv Milan, Dipartimento Sci Clin, Osped L Sacco, Milan, ItalyUniversidade Federal de São Paulo, Div Nephrol, Dept Med, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Dept Med, BR-04024002 São Paulo, BrazilFAPESP: 98/14303-3CNPq: 558924/2008-5Web of Scienc