TESTICULAR TOXICITY OF GALLIUM-ARSENIDE, INDIUM ARSENIDE, AND ARSENICOXIDE IN RATS BY REPETITIVE INTRATRACHEAL INSTILLATION

The testicular toxicities of two compound semiconductor materials, gal lium arsenide (GaAs) and indium arsenide (InAs), and arsenic oxide (As 2O3) were examined in rats by repetitive intratracheal instillation of these substances in suspension twice a week, a total of 16 times. A s ingle instillation dose was 7.7 mg/kg in the GaAs and the InAs groups and 1.3 mg/kg in the As2O3 group, A significant decrease in sperm coun t and significant increase in the proportion of morphologically abnorm al sperm were found in the epididymis in the GaAs group. Especially, a bnormal sperm with a straight head increased markedly in this group, I n the GaAs-treated rats, there was 40-fold increase in the degeneratin g late elongated spermatids at the postspermiation stages, stages IX, XI, and XI. From these results, it is indicated that GaAs disturbed th e spermatid head transformation at the late spermiogenic phases and ca used spermiation failure. InAs caused a sperm count decrease in the ep ididymis, though its testicular toxicity was relatively weak compared with that of GaAs. As2O3, a probable dissolution arsenic product of Ga As and InAs in vivo, did not show any testicular toxicities in this st udy, It seems likely that, along with arsenics, gallium and indium pla y a role in the testicular toxicities of GaAs and InAs. (C) 1996 Socie ty of Toxicology