Time-courses in renin and blood pressure during sleep in humans.
We previously described a strong concordance between nocturnal oscillations in plasma renin activity (PRA) and the rapid eye movement (REM) and non-REM (NREM) sleep cycles, but the mechanisms inducing PRA oscillations remain to be identified. This study was designed to examine whether they are linked to sleep stage-related changes in arterial blood pressure (ABP). Analysis of sleep electroencephalographic (EEG) activity in the delta frequency band, intra-arterial pressure, and PRA measured every 10 min was performed in eight healthy subjects. Simultaneously, the ratio of low frequency power to low frequency power + high frequency power [LF/(LF + HF)] was calculated using spectral analysis of R--R intervals. The cascade of physiological events that led to increased renin release during NREM sleep could be characterized. First, the LF/(LF + HF) ratio significantly (P < 10(-4) decreased, indicating a reduction in sympathetic tone, concomitantly to a significant (P < 10(- 3) decrease in mean arterial pressure (MAP). Delta wave activity increased (P < 10(-4) 10-20 min later and was associated with a lag of 0-10 min with a significant rise in PRA (P < 10(-4) . Rapid eye movement sleep was characterized by a significant increase (P < 10(-4) in the LF/(LF + HF) ratio and a decrease (P < 10(-4) in delta wave activity and PRA, whereas MAP levels were highly variable. Overnight cross-correlation analysis revealed that MAP was inversely correlated with delta wave activity and with PRA (P < 0.01 in all subjects but one). These results suggest that pressure-dependent mechanisms elicit the nocturnal PRA oscillations rather than common central processes controlling both the generation of slow waves and the release of renin from the kidney.
Charloux
A
A
Laboratoire des Régulations Physiologiques et des Rythmes Biologiques chez l'Homme, Institut de Physiologie, 4 Rue Kirschleger, 67085 Strasbourg Cedex, France. anne.charloux@physio-ulp.u-strasbg.fr
Piquard
F
F
Ehrhart
J
J
Mettauer
B
B
Geny
B
B
Simon
C
C
Brandenberger
G
G
D000328:Adult; D001341:Autonomic Nervous System / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D012083:Renin / Q000097:blood*; D012895:Sleep, REM / Q000502:physiology*
D012083:Renin