Tubuloglomerular feedback mechanisms in nephron segments beyond the macula densa.
OBJECTIVE
To summarize recent evidence regarding the role of distal nephron segments other than the macula densa in sensing the tubular environment and transmitting this signal to the adjacent vasculature.


RESULTS
In addition to the classical contact site between the macula densa plaque and the afferent arteriole, there is accumulating evidence suggesting a functional association between the distal nephron and the vasculature at three distinct additional sites: at the terminal cortical thick ascending limb, at the early distal tubule and also at the connecting tubule segment. The epithelial cells around the macula densa also sense and respond to changes in tubular flow and salt content and may transmit this signal to the adjacent afferent arteriole.


CONCLUSIONS
There are multiple sites of anatomical and functional contact between the distal nephron and the vasculature supplying the glomerulus, and these may contribute to the regulation of glomerular filtration rate and renal hemodynamics.
Komlosi
Peter
P
Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA. pkomlosi@uab.edu
Bell
Phillip D
PD
Zhang
Zhi-Ren
ZR
D000818:Animals; D005246:Feedback / Q000502:physiology; D006801:Humans; D007678:Kidney Glomerulus / Q000033:anatomy & histology / Q000502:physiology*; D007686:Kidney Tubules, Distal / Q000502:physiology*; D009399:Nephrons / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology