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Published on: May 18, 2010
Pathogenesis of limb and facial malformations induced by pyrimethamine in the rat
C Horvath1, A M Tangapregassom, M J Tangapregassom
1Laboratory of Physiopathology of Development, University Pierre et Marie Curie, Paris, France.
Insights
Pyrimethamine (PY) exposure during gestation caused limb and face malformations in rat embryos. Early hematomas in developing fetuses progressed to observable malformations by term.
Area of Science:
- Developmental toxicology
- Teratology
- Embryology
Background:
- Pyrimethamine (PY) is an antiparasitic drug.
- Drug-induced developmental abnormalities are a significant concern in public health.
- Understanding the teratogenic mechanisms of PY is crucial for risk assessment.
Purpose of the Study:
- To investigate the temporal sequence of morphological events leading to limb and face malformations.
- To characterize the developmental effects of pyrimethamine exposure in a rat model.
Main Methods:
- Female rats were administered pyrimethamine (30 mg/kg) or saline on gestation days 12-14.
- Embryos were collected at various gestational stages (14-21 days) for morphological examination.
- Control groups received only saline solution.
Main Results:
- Early exposure to PY resulted in hematomas in extremities and mandibulo-maxillary regions.
- Hematomas decreased, while malformations increased as gestation progressed.
- Malformations observed at term corresponded to the sites of initial hematoma formation.
Conclusions:
- Pyrimethamine exposure induces developmental abnormalities in rat embryos.
- The study elucidates a temporal progression from hematoma formation to malformation.
- Findings highlight the teratogenic potential of pyrimethamine on limb and facial development.
Abstract:
The temporal sequence of morphological events resulting in limb and face malformations was studied in pyrimethamine (PY) treated female rats, 30 mg/kg of PY in a 10 ml/kg suspension of 0.9% NaCl were administered i.p. on days 12, 13 and 14 of gestation. Controls received only 0.9% NaCl solution. The females were killed at different stages of gestation (between 14 and 21 days). Early PY treated embryos showed mainly haematomas in the extremities and the mandibulo-maxillary areas. During the course of gestation, fewer haematomas and more malformations were observed. At term, malformations were observed in the same localisations where haematomas were previously seen.
