Trial of platelet-derived growth factor antagonist, trapidil, in accelerated nephrotoxic nephritis in the rabbit.

The platelet-derived growth factor (PDGF) antagonist, trapidil, which also blocks the thromboxane and/or PG-endoperoxide receptor and is an inhibitor of thromboxane synthetase, was administered during rabbit accelerated nephrotoxic nephritis; the clinical and histological evolution was studied as well as urinary immunoreactive thromboxane (i-TXB2) and immunoreactive prostaglandin E2 (i-PGE2) excretion. Although the dose we used has been shown to be effective in vivo, and it inhibited the urinary i-TXB2 excretion on days 5 and 10, it neither inhibited the enhanced production of i-TXB2 on day 1, nor prevented the glomerular influx of monocytes on days 5 and 10. All clinical and histological data tend to be worse rather than better in trapidil-treated animals on days 5 and 10.