Effect of N-acetylcysteine on radiation-induced genotoxicity and cytotoxicity in rat bone marrow.

The aim of this study is to evaluate the potential radioprotective effects of N-acetylcysteine (NAC) against genotoxicity and cytotoxicity. The effect of WR-2721, as a representative of clinically used radioprotector, was compared with that of NAC, using the chromosomal aberration (CA) and micronucleus (MN) test systems in the irradiated rat's femoral bone marrow cells. We also investigated the mitotic index (MI), and the ratio of polychromatic erythrocytes (PCEs) to normochromatic erythrocytes (NCEs). The rats (n = 16) were divided randomly and equally into four groups: Control (C), Radiation (R), R+NAC (received irradiation and 1000 mg/kg NAC) and R+WR-2721 (received irradiation and 200 mg/kg WR-2721) rats. All the irradiated groups received whole-body gamma irradiation as a single dose of 6 Gy. Group R showed higher CA and MN formation when compared to C. Group R showed higher frequency of MN formation when compared to both R+NAC and R+WR-2721. The mean MI and PCE/NCE ratios were lower in Group R when compared to those of Group C. The mean MI and PCE/NCE ratios of both R+NAC and R+WR-2721 groups were lower when compared to those of Group C. The MI in Group R was lower when compared to that of both R+NAC and R+WR-2721 groups. In this study, the results give clues about the beneficial effects of NAC against radiation-induced genotoxicity and cytotoxicity in rat bone marrow and its effect may be comparable to that observed for WR-2721.

Lack of association between DRD3 gene polymorphism and response to clozapine in Turkish schizoprenia patients.

It is hypothesized that molecular components of dopaminergic system, especially the dopamine D3 receptor gene (DRD3), may play a crucial role in the pathophysiology of schizophrenia, because it is abundant in the limbic system of the brain and it binds antipsychotic drugs. Several groups attempted to find an association between a serine-to-glycine polymorphism of the DRD3 gene (Ser9Gly) and schizophrenia; however, the results were inconsistent. In this study, we aimed to investigate the relationship of the Serine/Glycine polymorphism of the DRD3 gene with therapeutic response to clozapine treatment between Turkish schizophrenia patients (N = 92) and healthy controls (N = 100). Genotype groups were comparable in BPRS, SAPS, SANS analysis of response to clozapine. Our results suggest that an association between the Ser/Gly polymorphism of DRD3 gene and response to clozapine in Turkish schizophrenia patients is unlikely to exist.