Effects of prenatal exposure to tributyltin and trihexyltin on behaviour in rats.

The effects of prenatal administration of tributyltin (1 and 5 mg/kg) and trihexyltin (5 mg/kg) upon the development and behavioural repertoire of rats were studied. The dose levels were selected so as not to induce maternal toxicity. No consistent delay upon occurrence of various maturation markers of the organotin-treated offspring was seen. As adults the tributyltin-treated offspring showed considerable hyperactivity following the initial habituation whereas the trihexyltin-treated offspring showed hyperactivity to a lesser degree. In the spatial learning tasks applied, the radial arm maze and the circular swim maze, tributyltin-treated rats demonstrated a clearly retarded aquisition of the radial arm maze task whereas trihexyltin-treated rats performed as well as the control rats; no differences were obtained in the swim maze task. The tributyltin-treated offspring showed a drastic potentiation of d-amphetamine-induced hyperactivity, whereas trihexyltin treatment induced only a marginal increase.

Age-dependent response of the rat testes to di(2-ethylhexyl) phthalate.

Spermatogenesis starts soon after birth in the Sprague-Dawley rat but is not fully established until about 56 days of age. When high oral doses of the plasticizer di(2-ethylhexyl) phthalate (DEHP) were given to rats of different ages, testicular damage was observed in immature but not in mature animals. Plasma concentration and urinary excretion data suggested that the gastrointestinal absorption of the DEHP-derived metabolite mono(2-ethylhexyl) phthalate was higher in young animals. Young rats were not more susceptible than older for repeated intravenous infusions of DEHP. It is suggested that the age-related difference observed in testicular response after oral administration of DEHP may be due to pharmacokinetic rather than tissue sensitivity differences. It is concluded that in assessing risks of testicular injuries in children exposed to DEHP, additional studies are required using species in which testicular development is more similar to that of humans.

Selective affinity of dimethyl sulphoxide (DMSO) and 2-amino-4-phenylsulphonylbenzenesulphonamide (NSD 3004) for the large intestinal mucosa of mice.

Whole-body autoradiography of 14C-labelled dimethyl sulphoxide and 35S-labelled 2-amino-4-phenylsulphonylbenzenesulphonamide revealed a selective accumulation of labelled substance in the large intestinal mucosa of mice. The mechanism of accumulation is discussed with regard to previous results on sulphone-containing compounds with tissue-specific distribution patterns.