Abstract
Earlier electron microscopy studies demonstrated morphological signs of fluid flow in the juxtaglomerular apparatus (JGA), including fenestrations of the afferent arteriole (AA) endothelium facing renin granular cells. We aimed to directly visualize fluid flow in the JGA, the putative function of the fenestrated endothelium, using intravital multiphoton microscopy of Munich-Wistar rats and C57BL6 mice. Renin content of the AA correlated strongly with the length of the fenestrated, filtering AA segment. Fluorescence of the extracellular fluid marker lucifer yellow (LY) injected into the cannulated femoral vein in bolus was followed in the renal cortex by real-time imaging. LY was detected in the interstitium around the JG AA before the plasma LY filtered into Bowman's capsule and early proximal tubule. The fluorescence intensity of LY in the JGA interstitium was 17.9 ± 3.5% of that in the AA plasma (n = 6). The JGA fluid flow was oscillatory, consisting of two components: a fast (one every 5-10 s) and a slow (one every 45-50 s) oscillation, most likely due to the rapid transmission of both the myogenic and tubuloglomerular feedback (TGF)-mediated hemodynamic changes. LY was also detected in the distal tubular lumen about 2-5 s later than in the AA, indicating the flow of JGA interstitial fluid through the macula densa. In the isolated microperfused JGA, blocking the early proximal tubule with a micropipette caused significant increases in MD cell volume by 62 ± 4% (n = 4) and induced dilation of the intercellular lateral spaces. In summary, significant and dynamic fluid flow exists in the JGA which may help filter the released renin into the renal interstitium (endocrine function). It may also modulate TGF and renin signals in the JGA (hemodynamic function).
| Original language | English |
|---|---|
| Journal | American Journal of Physiology - Renal Physiology |
| Volume | 291 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2006 |
Fingerprint
Keywords
- Fenestration
- Intravital microscopy
- Lucifer yellow
- Quinacrine
- Short-loop feedback
ASJC Scopus subject areas
- Physiology
Cite this
Fluid flow in the juxtaglomerular interstitium visualized in vivo. / Rosivall, L.; Mirzahosseini, Shahrokh; Toma, Ildikó; Sipos, Arnold; Peti-Peterdi, János.
In: American Journal of Physiology - Renal Physiology, Vol. 291, No. 6, 2006.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fluid flow in the juxtaglomerular interstitium visualized in vivo
AU - Rosivall, L.
AU - Mirzahosseini, Shahrokh
AU - Toma, Ildikó
AU - Sipos, Arnold
AU - Peti-Peterdi, János
PY - 2006
Y1 - 2006
N2 - Earlier electron microscopy studies demonstrated morphological signs of fluid flow in the juxtaglomerular apparatus (JGA), including fenestrations of the afferent arteriole (AA) endothelium facing renin granular cells. We aimed to directly visualize fluid flow in the JGA, the putative function of the fenestrated endothelium, using intravital multiphoton microscopy of Munich-Wistar rats and C57BL6 mice. Renin content of the AA correlated strongly with the length of the fenestrated, filtering AA segment. Fluorescence of the extracellular fluid marker lucifer yellow (LY) injected into the cannulated femoral vein in bolus was followed in the renal cortex by real-time imaging. LY was detected in the interstitium around the JG AA before the plasma LY filtered into Bowman's capsule and early proximal tubule. The fluorescence intensity of LY in the JGA interstitium was 17.9 ± 3.5% of that in the AA plasma (n = 6). The JGA fluid flow was oscillatory, consisting of two components: a fast (one every 5-10 s) and a slow (one every 45-50 s) oscillation, most likely due to the rapid transmission of both the myogenic and tubuloglomerular feedback (TGF)-mediated hemodynamic changes. LY was also detected in the distal tubular lumen about 2-5 s later than in the AA, indicating the flow of JGA interstitial fluid through the macula densa. In the isolated microperfused JGA, blocking the early proximal tubule with a micropipette caused significant increases in MD cell volume by 62 ± 4% (n = 4) and induced dilation of the intercellular lateral spaces. In summary, significant and dynamic fluid flow exists in the JGA which may help filter the released renin into the renal interstitium (endocrine function). It may also modulate TGF and renin signals in the JGA (hemodynamic function).
AB - Earlier electron microscopy studies demonstrated morphological signs of fluid flow in the juxtaglomerular apparatus (JGA), including fenestrations of the afferent arteriole (AA) endothelium facing renin granular cells. We aimed to directly visualize fluid flow in the JGA, the putative function of the fenestrated endothelium, using intravital multiphoton microscopy of Munich-Wistar rats and C57BL6 mice. Renin content of the AA correlated strongly with the length of the fenestrated, filtering AA segment. Fluorescence of the extracellular fluid marker lucifer yellow (LY) injected into the cannulated femoral vein in bolus was followed in the renal cortex by real-time imaging. LY was detected in the interstitium around the JG AA before the plasma LY filtered into Bowman's capsule and early proximal tubule. The fluorescence intensity of LY in the JGA interstitium was 17.9 ± 3.5% of that in the AA plasma (n = 6). The JGA fluid flow was oscillatory, consisting of two components: a fast (one every 5-10 s) and a slow (one every 45-50 s) oscillation, most likely due to the rapid transmission of both the myogenic and tubuloglomerular feedback (TGF)-mediated hemodynamic changes. LY was also detected in the distal tubular lumen about 2-5 s later than in the AA, indicating the flow of JGA interstitial fluid through the macula densa. In the isolated microperfused JGA, blocking the early proximal tubule with a micropipette caused significant increases in MD cell volume by 62 ± 4% (n = 4) and induced dilation of the intercellular lateral spaces. In summary, significant and dynamic fluid flow exists in the JGA which may help filter the released renin into the renal interstitium (endocrine function). It may also modulate TGF and renin signals in the JGA (hemodynamic function).
KW - Fenestration
KW - Intravital microscopy
KW - Lucifer yellow
KW - Quinacrine
KW - Short-loop feedback
UR - http://www.scopus.com/inward/record.url?scp=33845357155&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33845357155&partnerID=8YFLogxK
U2 - 10.1152/ajprenal.00203.2006
DO - 10.1152/ajprenal.00203.2006
M3 - Article
C2 - 16868308
AN - SCOPUS:33845357155
VL - 291
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0363-6119
IS - 6
ER -