Changes in nitric oxide levels in organogenic embryo and neural tube dysmorphogenesis after periconceptional murine alcohol ingestion

COLL, TA.; HOFMANN ORSETTI, C; GOLDSTEIN, J.; PAZ, DA.; CEBRAL, E.

Los Cocos, Córdoba, Argentina

Simposio; III Latin American Symposium on Maternal-Fetal Interaction and Placenta: Basic and Clinic Research (SLIMP); 2007

Asociación SLIMP

Since the pathogenic mechanisms of organogenic CNS following maternal alcohol consumption are little known, the aim was to study the role of nitric oxide (NO) production on organogenic embryo and neural tube (NT) development after periconceptional alcohol ingestion. Female mice were intoxicated with 10 % ethanol in drinking water for 15 days before and during pregnancy up to day 10 (T). Control females received water (C). T had increased % of organogenic embryos with open NT (5.4% vs 23.5%, p<0.001) and defective NT closure (4% vs 12%, p<0.001), desorganized neuroepithelium (H-E), reduced mitosis (p<0.01) and diminished body-cephalic proportion (scanning microscopy). It was found a reduced T-derived embryo percentage with cephalic NT-neuronal nitric oxide synthase (nNOS) positive immunoreactivity (C: 80% vs T: 62.5%). Endogenous and in-vitro T-embryo Nitrites (Ns) levels (Griess reaction, kit) were significantly diminished vs C-embryos (p<0.001, p<0.05). However, by evaluation of the endogenous embryonic NOS activity by NADPH-diaphorase reaction, a very increased % of strong NADPH-d stained whole embryos and cephalic region was detected in T vs C-derived embryos. The increment of Ns levels (Griess), after either NO-donors (Nonoate) or NOS inhibitors (L-NMMA) incubations, suggested an increased positive response of NOS activity (Ns) in T-embryos. In conclusion, periconceptional alcohol ingestion induce deficient NO levels and/or dysregulated NOS expression/activity leading to abnormal neurogenesis, neurodegeneration of cephalic NT and probably embryofetal microcephaly.