[Investigation on the influence of trimethoprim at the intrauterine development in the rat (author's transl)].

The present investigations was made to check the effects of repeated oral applications of the chemotherapeutic effective pirimidinsubstance trimethoprim (pure substance) at the intrauterine development in the wistar rat. The agent was given with a throat tube suspended in hydroxyacetylcellulose from the 5th to the 7th, from the 8th to the 10th and from the 11th to the 13th day p. c. The dosage was 1,500, 1,000, 750 and 200 mg trimethoprim per kg bodyweight. The valuation of the fetal development was made after the subsequent parameters: mean implantationrate, resorptionrate, mean fetal bodyweight. Statement of anomalies by inspection of the body surface shape and the brightened skeleton. The dosage of 200 mg TMP/kg bodyweight influences the fetal development only a little. Doses of 1,500, 1,000, and 750 mg TMP/kg bodyweight however show a high toxicity for the used rat strain as well for the mother animals as for the fetuses of the surviving animals. The observed increased resorption rates diminishing of the average fetal bodyweight, anomalies of the body shape and different anomalies of the skeleton are typical effects of folic acid antagonists.