The Day-Night Difference of Blood Pressure Is Increased in AT1A-Receptor Knockout Mice on a High-Sodium Diet

Abstract

AT(1A)-receptor deficiency, when combined with HSD, can increase circadian BP difference in mice. This increase is mediated principally by activity-unrelated factors, such as the nonsuppressibility of basal resting sympathetic tone by HSD, thus suggesting a form of salt-/volume-dependent hypertension.

Effects of Restricted Fructose Access on Body Weight and Blood Pressure Circadian Rhythms

“…In order to follow the L/D BP rhythm in our study, we used radiotelemetry for BP monitoring in conscious, undisturbed mice. 24 hr BP recordings showed, as expected, that control mice exhibited light/dark circadian oscillations with lower BP seen during the light period, the inactive period for mice [4, 31–33]. When fructose access was restricted to the light phase (F12L), the light/dark BP rhythm was nonexistent.…”

Brain angiotensin AT1 receptors as specific regulators of cardiovascular reactivity to acute psychoemotional stress

“…Given that mental and physical activities are critical contributors to ultradian and circadian BP variations, 105,106 these results indicate that AT 1 receptors play little role in cardiovascular adjustments to these routine activities. Similarly, the pressor and tachycardic responses to induced behavioural activation (placing mice in a new clean cage with a standard wood chip bedding) was similar in AT 1A −/− or AT 1A +/+ mice, as was the locomotor response 104 . Moreover, initial experiments using synchronized video and BP telemetry recording indicate that other natural activities in home cages, including exploring, sniffing/orienting, grooming and drinking, caused very similar pressor responses in AT 1A −/− and AT 1A +/+ mice (CA Chavez, KHC Choy & DN Mayorov unpubl.…”

“…However, recent observations suggest that this role may be limited. In particular, cardiovascular arousal associated with spontaneous ultradian activity bouts does not differ between AT 1A −/− and AT 1A +/+ mice 104 . Given that mental and physical activities are critical contributors to ultradian and circadian BP variations, 105,106 these results indicate that AT 1 receptors play little role in cardiovascular adjustments to these routine activities.…”

“…In particular, cardiovascular arousal associated with spontaneous ultradian activity bouts does not differ between AT 1A ) ⁄ ) and AT 1A + ⁄ + mice. 104 Given that mental and physical activities are critical contributors to ultradian and circadian ''The inhibitory role of central AngII'' Ó 2011 The Author Clinical and Experimental Pharmacology and Physiology Ó 2011 Blackwell Publishing Asia Pty Ltd BP variations, 105,106 these results indicate that AT 1 receptors play little role in cardiovascular adjustments to these routine activities. Similarly, the pressor and tachycardic responses to induced behavioural activation (placing mice in a new clean cage with a standard wood chip bedding) was similar in AT 1A…”

“…) ⁄ ) or AT 1A + ⁄ + mice, as was the locomotor response. 104 Moreover, initial experiments using synchronized video and BP telemetry recording indicate that other natural activities in home cages, including exploring, sniffing ⁄ orienting, grooming and drinking, caused very similar pressor responses in AT 1A…”