Re. Chapin et al., THE REPRODUCTIVE AND DEVELOPMENTAL TOXICITY OF INDIUM IN THE SWISS MOUSE, Fundamental and applied toxicology, 27(1), 1995, pp. 140-148
Indium is increasingly used in a variety of industries, and while ther
e are few studies of its developmental toxicity, there are no reports
of its potential reproductive toxicity. These studies were undertaken
to investigate the possible reproductive toxicity of indium and to det
ermine the relative vulnerability of males and females. We used, initi
ally, a 21-day combined developmental/reproductive toxicity protocol.
Oral exposures to InCl3 (less than or equal to 250 mg/kg) were without
effect on the male reproductive system or liver. A kidney effect was
demonstrated in males by a decrease in urinary N-acetyl glucosaminidas
e. The ability of females to become pregnant was unaffected. However,
fetal development was adversely affected, manifested as increased intr
auterine deaths in the presence of reduced maternal weight gain. A dev
elopmental toxicity study identified no increase in fetal malformation
s, but verified the increased fetal deaths, in the absence of effects
on adjusted maternal body weight. In vitro toxicity studies showed tha
t the embryolethality was at least in part a result of direct toxicity
to the conceptus, with effective doses in the low micromolar range. A
limited disposition study showed that fetuses contained low micromola
r concentrations of indium, more indium than maternal liver, and compa
rable to levels that were toxic in vitro. Although studies of greater
exposure duration are required for risk assessment, these data indicat
e that fetal development is likely to be more affected by indium than
female or male reproduction, with adverse effects occurring at low mic
romolar levels in vivo and at exposures that may or may not affect bod
y weight. (C) 1995 Society of Toxicology.