RESUMO
The liver plays a central role in lipid metabolism, and abnormal lipid accumulation in the liver is a key feature of Non-Alcoholic Fatty Liver Disease. In experimental studies, quantification of liver steatosis is commonly based on lipids staining or biochemical analysis. Here, we present a spectroscopic approach for quantitative analysis of the lipid content in the freeze-dried liver. The method is based on vibrational spectroscopy (Raman and infrared) measurements applied for Partial Least Squares (PLS) regression modeling. The obtained PLS models show a good correlation of the spectroscopic data with the reference histological evaluation of steatosis based on Oil Red O (ORO)-stained images of liver cross sections. Vibrational spectroscopy with PLS-based modeling described here represents a useful approach for the fast assessment of the liver steatosis in a small sample of freeze-dried liver tissue. In conclusion, our work demonstrates the easy-to-use method that can be applied in laboratory routine as a beneficial alternative to the established ORO staining.
Assuntos
Fígado Gorduroso/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Animais , Fígado Gorduroso/patologia , Análise dos Mínimos Quadrados , Lipídeos/análise , Fígado/química , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodosRESUMO
Electric reactions of the identified neurons in adult (10-12 months) and old (22-24 months) molluscs Lymnaea stagnalis to endogenous peptide isolated from the water soluble fraction of the Helix Pomatia brain homogenate as well as to vasopressin are studied. The endogenous peptide causes a significant activation of the burst both in adult and old neurons of the molluscs. No significant age-related differences in the pronouncement of the above shifts of the molluscan neurons are found. There is an increased sensitivity to the identified peptide, vasopressin, in the old individuals. A non-uniform change in the sensitivity of mollusk neurons to various neuropeptides may affect the synaptic conduction in old age.