Characteristics of renal sympathetic nerve single units in @entity95 with angiotensin-induced XXXX .

@entity101 @entity2944 @entity4486 @entity4774 @entity95 @entity519 @entity1017 @entity23374
UNASSIGNED: We examined the effect of chronic angiotensin ( @entity23374 ) @entity101 on activity of post-ganglionic renal sympathetic units to determine whether altered whole renal nerve activity is due to recruitment or changes in firing frequency. @entity95 were treated with low (20ng/kg/min, 8  weeks) or high (50ng/kg/min, 4  weeks) dose @entity23374 before the experiment under @entity4486 - @entity4774 anaesthesia. Spontaneously active units were detected from multi-unit recordings using an algorithm that separated units by action potential shape using templates that matched spikes within a prescribed standard deviation. Multi-unit sympathetic nerve activity was 40% higher in low dose @entity23374 than sham (P  =  0.012) but not different in high @entity23374 @entity95 . Resting firing frequency was similar in sham (1.00      0.09  spikes/s, n  =  144) and high @entity23374 @entity95 (1.10      0.08  spikes/s, n  =  112) but was lower with low @entity23374 (0.65      0.08  spikes/s, n  =  149, P<0.05). Unit firing rhythmicity was linked to the cardiac cycle and was similar in sham and low @entity23374 groups but 29-32% lower in high @entity23374 @entity95 (P<0.001). Cardiac linkage followed a similar pattern during @entity519 . All units showed baroreceptor dependency. @entity1017 and range were reduced and curves shifted to the right in @entity23374 groups. Firing frequency during @entity519 increased by +39% in low @entity23374 and +82% in shams but the greatest increase was in the high @entity23374 group (+103%, Pdose  =   0.001). Responses to @entity2944 were similar in all groups. Increases in sympathetic outflow in low dose chronic @entity23374 @entity101 are due to recruitment of neurons but high dose @entity23374 increases firing frequency to chemoreceptor stimuli independently of the arterial baroreceptors. This article is protected by copyright. All rights reserved.
