RESUMO
El etanol y el isopropanol son, de los alcoholes alifáticos de cadena corta, los más frecuentemente asociados a la actividad humana tanto a nivel industrial como en el entorno doméstico. En este trabajo se presentan los principales hallazgos reportados en la literatura para ensayos de genotoxicidad y teratogénesis en modelos experimentales de distinto nivel de complejidad, con especial énfasis en Drosophila melanogaster. El metabolismo de estos alcoholes es semejante en Drosophila y en humanos por lo cual la mosca es un buen modelo in vivo para la evaluación de sus potenciales efectos tóxicos, genotóxicos y teratogénicos.
Ethanol and isopropanol are two of the short chain aliphatic alcohols more frequently associated to the human environment, both in the industrial and domestic conditions. The aim of this work was to present the main findings reported in the literature about their genotoxicity and teratogenicity in experimental models of different level of complexity, with special emphasis in Drosophila melanogaster. Taking into account that the metabolism of both alcohols in Drosophila and humans is similar, the fly is a good model for the evaluation of their potentially toxic, genotoxic and teratogenic effects.
Assuntos
Animais , 2-Propanol/metabolismo , 2-Propanol/toxicidade , Etanol/metabolismo , Etanol/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Genotoxicidade/análise , Teratogênicos/análise , Toxicogenética/métodosRESUMO
Isopropanol (isopropyl alcohol, 2-propanol, IPA) is a volatile solvent widely used in domestic or industrial environments and reported as innocuous in various test systems. The aim of this work was to search for in vivo genotoxic effects of IPA in Drosophila melanogaster, studying its ability to induce nondisjunction (ND) in females, sex linked recessive lethals (SLRL) in males, and somatic mutation and/or recombination (SMART) in larvae. Treatments were acute (60min) and were administered via inhalation. IPA had low toxicity in adult flies (75% IPA mortality index, MI=12.7% (females) and 2.6% (males)) and larvae (MI=14.3%, 75% IPA). Female fertility was severely affected during the first 24h (brood I, BI) after treatment, but, afterwards, control values were recovered. IPA induced a 50-fold increase of ND (%) in 24h old females, and a six-fold rise in 4-5 d old BI offspring. Nondisjunction frequencies (%) in the offspring of broods II to V (24h in each case) were similar to control values. IPA doses of 25% and 50% (v/v), tested in 24h old females, showed a significant dose-dependent increase of ND(%)in BI only, with control values in subsequent broods. Flies gave normal offspring when kept in regular media for 24h before mating. The eye spot test (SMART) showed a significant increase at 50% IPA (p<0.05, m=2), but the response was not dose-dependent. IPA failed to induce SLRL in any of the spermatogenesis stages tested. These findings suggest that the main effect of IPA is to induce chromosomal malsegregation; IPA must be present at the resumption of M-phase I after fertilization, to exert these effects. The alcohol does not affect DNA directly, but perturbations of the nuclear membrane may be responsible for induction of ND.