RESUMEN
The distribution of mRNA transcripts corresponding to the alpha7 and alpha8 subunits of the nicotinic acetylcholine receptors (nAChRs) was studied in selected structures of the chick visual system with non-radioactive in situ hybridization and immunohistochemical techniques. The results indicated that the alpha7 and alpha8 nAChR transcripts are widely distributed in the brain, exhibiting differential expression in some structures but also some degree of co-localization. The pattern of localization of alpha7 and alpha8 nAChR transcripts was highly correlated with immunohistochemical data, with very few instances of possible mismatches between the distribution of mRNAs and their corresponding proteins.
Asunto(s)
Cuerpos Geniculados/química , Receptores Nicotínicos/análisis , Receptores Nicotínicos/genética , Colículos Superiores/química , Animales , Pollos , Fibras Colinérgicas/química , Fibras Colinérgicas/fisiología , Expresión Génica/fisiología , Cuerpos Geniculados/citología , Cuerpos Geniculados/fisiología , Técnicas para Inmunoenzimas , Hibridación in Situ/métodos , ARN Mensajero/análisis , Receptores Nicotínicos/inmunología , Colículos Superiores/citología , Colículos Superiores/fisiología , Receptor Nicotínico de Acetilcolina alfa 7RESUMEN
Cytogenetic techniques, the micronucleus (MN) assay, in particular, have been widely used in population monitoring, biological dosimetry and early detection of groups susceptible to cancer. Individuals respond differently to several environmental agents. The efficiency of the cellular repair mechanisms would be responsible, at least to some extent, for individual differences in sensitivity to neoplasia. In order to determine the sensitivity of cancer patients to ionizing radiation, blood cultures from untreated individuals with basocellular carcinoma, young healthy subjects and older healthy subjects, were irradiated in vitro with 60Co at doses ranging from 0 to 500 cGy and submitted to the cyto-B micronucleus assay; the frequency of cells and distribution of MN and dose-response relationships were analyzed. Results showed that cancer patients had a lower frequency of cells with spontaneous MN than older healthy subjects. The frequency of micronucleated cells was not different in patients and healthy subjects, but not the distribution of MN per radiation dose: for the carcinoma group, while the proportion of cells with one MN decreases drastically, the proportion of the cells with two or more MN increases with the same intensity. Our results show that the proportion of damaged cells is similar in patients with basocellular carcinoma and healthy subjects, but the magnitude of radiation-induced lesion is greater in the cancer patients.