2013-12-062013-12-062013-05-24HAGE, Amanda Anastácia Pinto. Caracterização lipídica de duas cepas de Leishmania (Viannia) braziliensis causadoras da leishmaniose tegumentar americana. 2013. 53 f. Dissertação (Mestrado) - Universidade Federal do Pará, Instituto de Ciências Biológicas, Belém, 2013. Programa de Pós-Graduação em Neurociências e Biologia Celular.https://repositorio.ufpa.br/handle/2011/4508The american cutaneous leishmaniasis (ACL) is an infectious disease caused by protozoa of the genus Leishmania with high incidence in the Amazon region. A variety of leishmania species are responsible for this pathology. Thus, depending on the species and the immune response of the vertebrate host, the disease can display different clinical forms, including localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL). The main species responsible for the LTA is Leishmania (Viannia) braziliensis. However, due to existence of a multiplicity of strains of this species and reduced number of related studies, it is important to know the basic metabolic aspects of the protozoa such as lipid metabolism in an attempt to characterize pathways or components essential to their development and infectivity. This study aimed to analyze the distribution of lipid droplets (LD) and lipid profile of two strains of L. (V.) braziliensis isolated from different clinical cases at different periods of the stationary phase of cell growth. The promastigotes of strains M17593 (LCL) and M17323 (LMC) of L. (V.) braziliensis were used in early stationary phase (STAT-E) and late stationary (STAT-L) of the growth. Initially, was performed ultrastructural analysis of promastigotes by transmission electron microscopy (TEM) and we could observe structures suggestive of LD distributed in the cytoplasm of the parasite, confirmed by imidazole-osmium cytochemical technique, organelles required for energy metabolism of the parasite. To quantify the LD distribution between the days of cultivation and between the different strains, analysis was performed by flow cytometry with BODIPY ® 493/503. The results showed that the MCL strain had a higher amount of LD during the late stationary phase. In LCL strain no significant difference was observed between the phases studied. Thus, it can be suggested that the increase inflammatory response that occurs in patients with MCL, is associated with LD accumulation in parasite, energy and eicosanoids source, such prostaglandins. Another hypothesis is the possible correlation between LD and the low phosphatidylserine exposure to the external surface of the membrane, important to parasite infectivity. For the total lipids analysis, parasites were subjected to lipid extraction, followed by HPTLC technique, which were found predominantly phospholipids, sterol esterified, sterols, triglycerides and fatty acids composing the parasite, with variations between strains and between phases studied. The LCL strain in late stationary phase has a higher amount of total lipids, which can be explained because this strain already known as the infective one, and possibly present high quantities of glycoconjugates associated with lipid subdomains important for the recognition of phagocytes. It is important to know the high infectivity of LCL strain compared to MCL strain, results in less inflammation. These results indicate that exist difference in lipid profile and LD distribution between different strains of L. (V.) braziliensis, which may be related to the parasite infectivity and the clinical manifestation of the disease.porAcesso AbertoDoenças transmissíveisLeishmaniose tegumentar americanaCorpos lipídicosCepasAmazônia brasileiraDissertaçãoCNPQ::CIENCIAS BIOLOGICAS::PARASITOLOGIA