1 Tiopronin (N-(2-mercaptopropionyl)-glycine) is a drug with a free thiol (
sulphydryl) group that is used clinically. We have reported previously that
tiopronin protects rat kidney slices in vitro from the nephrotoxic effects
of cisplatin and does not reduce the antitumour activity of cisplatin, Tio
pronin has been investigated therefore for its protective effects in rats i
n vivo. 2 The extent of kidney damage was studied 5 days after the administ
ration of cisplatin. A single injection (i.p.) of cisplatin (6 mg/kg; 20 mu
mol/kg) to female Wistar albino rats caused a sustained decrease in body w
eight and, after 5 days, plasma urea, creatinine and kidney weight were inc
reased. Tiopronin (2.5 mmol/kg, p.o.) ameliorated cisplatin nephrotoxicity
when given 1 h before cisplatin. Tiopronin provided marked protection again
st cisplatin-induced increases in urea (from 237+/-19 mg to 48+/-23 mg/100
ml; control: 17+/-1) and creatinine (from 6.5+/-0.5 to 1.7+/-0.5 mg/100 ml
control: 1.0+/-0.1). Tiopronin did not, prevent the bo dy weight loss cause
d by cisplatin. In addition, an intraperitoneal dose (1 mmol/kg) of tiopron
in afforded similar protection to that of an oral dose. Rats that received
an i.p. mixture of cisplatin (6 mg/kg) and tiopronin (65 mg/kg) displayed g
enerally less toxicity, as indicated by a small fall in body weight and sma
ller increases in urea and creatinine and kidney weight. 3 The results show
that tiopronin protects against cisplatin-induced nephrotoxicity. Oral adm
inistration of tiopronin may be a clinically useful way to prevent cisplati
n nephrotoxicity.