RESUMO
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.
Assuntos
Face/anormalidades , Ossos Faciais/anormalidades , Deformidades Congênitas dos Membros , Pirimetamina/toxicidade , Teratogênicos , Animais , Feminino , Hematoma/induzido quimicamente , Hematoma/embriologia , Gravidez , Ratos , Ratos Endogâmicos , Valores de ReferênciaRESUMO
Pyrimethamine injected into the rat on days 12, 13, and 14 of gestation induces several types of malformations, including limb and facial deformities. These malformations appear in the same location as the hemorrhages and hematomas induced by this substance. In order to visualize the extent of the vascular disorders in the affected areas, a polymerizable substance was injected intravenously into the fetus. After pyrimethamine treatment, the fetal vascular network was simplified and reorganized in a different way according to the severity of the malformations. The appearance of vascular pathology, followed by malformations in the same regions, raises the hypothesis of a vascular cause of fetal defects.
Assuntos
Anormalidades Induzidas por Medicamentos/etiologia , Pirimetamina/toxicidade , Doenças Vasculares/induzido quimicamente , Animais , Embrião de Mamíferos/efeitos dos fármacos , Extremidades/irrigação sanguínea , Feminino , Feto/efeitos dos fármacos , Idade Gestacional , Hemorragia/induzido quimicamente , Membro Posterior/anormalidades , Deformidades Congênitas dos Membros , Gravidez , Radiografia , Ratos , Ratos Endogâmicos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Doenças Vasculares/diagnóstico por imagemRESUMO
The evolution of the anterior hypothalamic neurosecretion is studied in control, sham-operated and portocaval shunt rats. In sham-operated related to control rats, no modification of the anterior hypothalamic neurosecretion is observed. In portocaval shunt rats, the hypothalamic neurosecretion increases. This increase is mainly observed into the median eminence in all the portocaval shunt rats. The hypothesis according to which the modification of neurosecretory acitivity of the hypothalamic structures may be related to a discrepancy between the central monoamines is discussed.
Assuntos
Hipotálamo Anterior/metabolismo , Hipotálamo/metabolismo , Derivação Portocava Cirúrgica , Animais , Modelos Animais de Doenças , Encefalopatia Hepática/metabolismo , Hipotálamo Anterior/patologia , Masculino , Eminência Mediana/metabolismo , RatosAssuntos
Fenclonina/farmacologia , Animais , Masculino , Ratos , Timo/efeitos dos fármacos , Timo/patologiaRESUMO
Parenteral administration of PCPA (200 mg/kg) induces changes in the quantitiy and the distribution of hypothalamic neurosecretion. This action appears very quickly and increases during the 48 hours following the injection. The histologic observations disclose a large accumulation of neurosecretory material in the supraoptic nuclei and in the accessory magnocellular groups of the anterior hypothalamus. In the median eminence large Herring bodies are seen. These results are to be compared to those obtained after mesencephalic raphes lesioning. The histologic alterations observed in the anterior hypothalamic level, may be due to complex disturbances involving the monoaminergic neuromediation.
