biostudies-literatureGessner EENIEHS NIH HHS860-872https://www.ebi.ac.uk/biostudies/studies/S-EPMC9233140biostudies-literatureUnknown31(5)Carmofur is an antineoplastic agent that inhibits ceramidase, a key enzyme in the sphingolipid pathway. Previous research suggests carmofur represses reproductive maturity in Daphnia magna. The purpose of this experiment was to confirm carmofur's effects on fecundity and reproductive maturity over two generations. A chronic toxicity test found reproductive maturity was delayed from 9 to 19 days by 0.80 μM carmofur with a 99.7% drop in reproduction, probably caused by delayed ovarian development. Second generation effects were even greater with 0% reproductive success at 0.40 μM. To our surprise, carmofur was not measured in the media by HPLC 24 h after exposure. Previous research indicated that carmofur is unstable in water and hydrolyzed into 5-fluorouracil (5-FU). Therefore, the chronic Ecotoxicology (London, England)The reproductive effects of the cancer chemotherapy agent, Carmofur, on Daphnia magna are mediated by its metabolite, 5-Fluorouracil.PMC9233140R15 ES017321Westbrook NEvan den Hurk PBaldwin WSGessner EEGhent BNShah MHfalseThe reproductive effects of the cancer chemotherapy agent, Carmofur, on Daphnia magna are mediated by its metabolite, 5-Fluorouracil.Carmofur is an antineoplastic agent that inhibits ceramidase, a key enzyme in the sphingolipid pathway. Previous research suggests carmofur represses reproductive maturity in Daphnia magna. The purpose of this experiment was to confirm carmofur's effects on fecundity and reproductive maturity over two generations. A chronic toxicity test found reproductive maturity was delayed from 9 to 19 days by 0.80 μM carmofur with a 99.7% drop in reproduction, probably caused by delayed ovarian development. Second generation effects were even greater with 0% reproductive success at 0.40 μM. To our surprise, carmofur was not measured in the media by HPLC 24 h after exposure. Previous research indicated that carmofur is unstable in water and hydrolyzed into 5-fluorouracil (5-FU). Therefore, the chronic 2022-01-01T00:00:00Z2022 Jul2025-04-26T07:39:07.802Z2025-04-06T12:22:40.109ZS-EPMC92331403557976110.1007/s10646-022-02551-5