[Peritubular capillary injury in Chinese herb guan-mu-tong-induced acute tubular necrosis].
OBJECTIVE
To explore the role and mechanisms of peritubular capillary (PTC) injury in the progression of Chinese Herb guan-mu-tong (GMT, aristolochiae manshuriensis kom) induced acute tubular necrosis (GMT-ATN).


METHODS
Renal biopsy tissue from 4 cases of GMT-ATN and 5 cases of antibiotic induced ATN (A-ATN) were included in the study. Tubulointerstitial injury was semi-quantitatively assessed. Immunohistochemical SP method was applied to reveal PTC as well as the expression of vascular endothelial growth factor (VEGF). Ultra microstructure of endothelial cells and basement membrane of PTC was detected by electronic microscopy (EM). 5 cases of minor mesangioproliferative non-IgA glomerulonephritis were selected as a control group.


RESULTS
The density of PTC was decreased significantly in GMT-ATN, as compared with the A-ATN and control group (211.08 +/- 56.15 vs 413.54 +/- 66.59, 536.62 +/- 68.38, P < 0.01). Dilated and deformed PTC lumina were noted in GMT-ATN with some endothelial cells and basement membrane partially disrupted. Most endothelial cells were found to be swollen with vacuoles dispersed in the cell plasma. The basement membrane was partially shrunk and thickened. The expression of VEGF in renal tubular epithelial cells (RTEC) was much less in the GMT-ATN than that in A-ATN group 2.1 (0-3.86)% vs [42.5 (31.33-60.25)%, P < 0.01], even though it was higher than that in the control group [23.1 (18.2-39.5)%, P < 0.01]; the expression was correlated with PTC density. Close correlation was also found between RTEC regeneration and PTC density, as well as VEGF expression (r = 0.880 and 0.802 respectively, P < 0.01).


CONCLUSIONS
PTC was markedly injured in GMT-ATN; this could be one of the cause for the continuously progressing tubulointerstitial damage. The low expression of VEGF in RTEC might contribute to the PTC injury process.
Yang
Li
L
Institute of Nephrology and Division of Nephrology, First Hospital, Peking University, Beijing 100034, China.
Li
Xiao-mei
XM
Wang
Su-xia
SX
Wang
Hai-yan
HY
D000328:Adult; D030022:Aristolochia / Q000737:chemistry; D001485:Basement Membrane / Q000648:ultrastructure; D002196:Capillaries / Q000473:pathology; D004365:Drugs, Chinese Herbal / Q000009:adverse effects* / Q000302:isolation & purification; D042783:Endothelial Cells / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007120:Immunochemistry; D007683:Kidney Tubular Necrosis, Acute / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D007684:Kidney Tubules / Q000098:blood supply*; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D004365:Drugs, Chinese Herbal; D042461:Vascular Endothelial Growth Factor A