ABSTRACT
Single-wall carbon nanotubes (SWCNTs) and polyamidoamine dendrimers (PAMAM) have been proposed for a variety of biomedical applications. The combination of both molecules makes this new composite nanomaterial highly functionalizable and versatile to theranostic and drug-delivery systems. However, recent toxicological studies have shown that nanomaterials such as SWCNTs and PAMAM may have high toxicity in biological environments. Aiming to elucidate such behavior, in vitro studies with different cultured cells have been conducted in the past few years. This study focuses on the effects of SWCNT-PAMAM nanomaterials and their individual components on the C2C12 murine cell line, which is a mixed population of stem and progenitor cells. The interactions between the cells and the nanomaterials were studied with different techniques usually employed in toxicological analyses. The results showed that SWCNT-PAMAM and PAMAM inhibited the proliferation and caused DNA damage of C2C12 cells. Data from flow cytometry revealed a less toxicity in C2C12 cells exposed to SWCNT compared to the other nanomaterials. The results indicated that the toxicity of SWCNT, SWCNT-PAMAM and PAMAM in C2C12 cells can be strongly correlated with the charge of the nanomaterials.
Subject(s)
Cell Proliferation/drug effects , DNA Damage , Dendrimers/toxicity , Myoblasts/drug effects , Nanoconjugates/toxicity , Nanotubes, Carbon/toxicity , Animals , Apoptosis/drug effects , Cell Adhesion/drug effects , Cell Culture Techniques , Cell Line , Cell Survival/drug effects , Comet Assay , Flow Cytometry , Mice , Myoblasts/pathologyABSTRACT
The indiscriminate use of anabolic-androgenic steroids has been shown to induce left ventricular dysfunctions. The main objective of the present study was to investigate the effects of nandrolone decanoate on matrix metalloprotease (MMP-2) activity and protein level in the left ventricle (LV) of rats after 7 weeks of mechanical load exercise. Wistar rats were grouped into: sedentary (S); nandrolone decanoate-treated sedentary (AAS); trained without AAS (T) and trained and treated with AAS (AAST). Exercised groups performed a 7-weeks water-jumping program. Training significantly increased the MMP-2 activity by zymography and the protein level by Western blotting analysis. However, the AAS treatment abolished both the increase in MMP activity and protein level induced by exercise. These results suggest that AAS may impair cardiac tissue remodeling which may lead to the heart malfunction.
Subject(s)
Anabolic Agents/pharmacology , Heart Ventricles/drug effects , Matrix Metalloproteinase Inhibitors , Nandrolone/analogs & derivatives , Animals , Blotting, Western , Heart Ventricles/enzymology , Male , Nandrolone/pharmacology , Nandrolone Decanoate , Physical Conditioning, Animal , Rats , Rats, WistarABSTRACT
O musculo possui uma habiliade inerente de adpatacao diante de variadas condicoes, como tipo de inervacao, atuacao de hormonios, atividade contratil (treinamento), condicao de alongamento, o proprio crescimento pos-natal, entre outros. Ha grande correlacao entre a isoforma de cadeia pesada de miosina (CPM) expressa e a funcao muscular. O presente estudo teve por objetivo estudar o remodelamento muscular por meioda analise da expressao das diferentes isoformas de CPM de musculo esqueletico em ratos submetidos a treinamento fisico. A metodologia utilizada consistiu em treinamento de ratos albinos (n=10), machos, em protocolo de natacao, em um periodo de 6 horas/dia, em 3 sessoes de 2 horas, com intervalos de 30 minutos entre cadasessao, totalizando 5 dias de treinamento. Ao termino do treinamento, os animais foram sacrificados para extracao do musculo soleo. Foi feita extracao de RNA total e posterior reacao de RT-PCR utilizando oligonucleotideos iniciadores especificos para as diferentes isoformas de CPM. Tambem foi realizada, a partir de extratos proteicos do musculo retirado, a separacao eletroforetica das isiformas de CPM, utilizando SDS-PAGE com gradiente de (7 - 10 por cento). Os resultados obtidos com a tecnica de RT-PCR demonstrarm expressao de todas as isoformas de CPM, tanto em ratos sedentarios como nos treinados. Apesar de a analise nao ter sido feita de forma quantitativa, parece haver tendencia de aumento especialmente das isiformas IIa e IIx com a evolucao do treinamento. A separacao eletroforetica das isoformas mostrou que nao houve alteracao na expressao das isoformas de CPM (I, IIa, IIb e IIx) com o treinamento
