Salicylate-Induced Foetal Damage in Two Mouse Strains: Studies on the Distribution of 14C-Labelled Salicylic Acid

The distribution of salicylate was studied in pregnant and non-pregnant mice of the A/Jax and CBA strains. These strains were selected because of their different susceptibility to salicylate-induced foetal damage. Labelled salicylic-1-¹⁴C-acid (1 μci) was injected intramuscularly together with 10 mg sodium salicylate as cold carrier in a volume of 0.1 ml distilled water/20 g bodyweight. The animals were sacrificed at different intervals from half an hour to 8 hours after the injection and the radioactivity in the maternal blood and liver and in the foetuses was determined by liquid scintillation counting. The non-pregnant mice showed initially a higher radioactivity in the blood than in the females on day 14 or 17 of gestation. The amount of liver radioactivity was similar in pregnant and non-pregnant animals and remained practically unchanged during the period of study. The foetal radioactivity was relatively high compared to that in the maternal liver. No strain difference were observed either on gestation day 14 or on day 17. The foetal radioactivity did not decrease during the first 4 hours after salicylate treatment on day 17 of gestation at which time foetal damage had already been produced.