AJP - Renal Physiology, Vol 249, Issue 2 241-F250, Copyright © 1985 by American Physiological Society
Anti-GBM antibody-induced proteinuria in isolated perfused rat kidney
W. G. Couser, C. Darby, D. J. Salant, S. Adler, M. M. Stilmant and L. M. Lowenstein
The effect of anti-GBM antibody on protein excretion was studied in
isolated rat kidneys perfused with 20 mg of sheep anti-rat GBM
(experimental) or nonantibody sheep IgG (control). Six control kidneys
excreted 176 +/- 31 micrograms/min of BSA initially, rising to 296 +/- 111
micrograms/min at 2 h. Fractional clearance of BSA rose from 0.51 to 1.70%.
Eight experimental kidneys excreted 211 +/- 56 micrograms/min of BSA,
increasing to 1,924 +/- 804 micrograms/min at 2 h. Fractional BSA clearance
increased from 0.56 to 11.49%. After 60 min, BSA excretion in
anti-GBM-perfused kidneys exceeded controls by a factor of 6.5-7.9 (P less
than 0.05) and fractional BSA clearance exceeded controls by a factor of
5.8-7.1 (P less than 0.05). Studies with fluorescent markers indicated
proteinuria to be of glomerular origin in antibody-perfused kidneys. There
were no significant differences between anti-GBM-perfused and control
kidneys in perfusion pressures, perfusate flow rates, urine flow rates,
inulin clearance, or sodium reabsorption. Antibody to GBM can induce a
marked increase in glomerular permeability to BSA and IgG without
participation of other systemic humoral or cellular mediation systems.
