title: Liver autofluorescence properties in animal model under altered nutritional conditions.
abstract: Autofluorescence spectroscopy is a promising and powerful approach for an in vivo, real time characterization of liver functional properties. In this work, preliminary results on the dependence of liver autofluorescence parameters on the nutritional status are reported, with particular attention to vitamin A and lipid accumulation in liver tissue. Normally fed and 24 h starving rats were used as animal models. Histochemical and autofluorescence analysis showed that lipids and vitamin A colocalize in the liver parenchyma. Fasting condition results in a parallel increase in both lipids and vitamin A. Autofluorescence imaging and microspectrofluorometric analysis carried out on unfixed, unstained tissue sections under 366 nm excitation, evidenced differences in both spectral shape and response to continuous irradiation between liver biopsies from fed and starving rats. As to photobleaching, in particular, fitting analysis evidenced a reduction of about 85% of the signal attributable solely to vitamin A during the first 10 s of irradiation. The tissue whole emission measured in fed and starving rat livers exhibited reductions of about 35% and 52%, respectively, that are closely related to vitamin A contents. The findings open interesting perspectives for the set up of an in situ, real time diagnostic procedure for the assessment of liver lipid accumulation, exploiting the photophysical properties of vitamin A.
authors.affiliation: IGM-CNR Histochemistry and Cytometry Section and Department of Animal Biology, University of Pavia, Piazza Botta, 10, 27100, Pavia, Italy.
authors.forename: Anna Cleta
authors.initials: AC
authors.lastname: Croce
authors.forename: Uliana
authors.initials: U
authors.lastname: De Simone
authors.forename: Mariapia
authors.initials: M
authors.lastname: Vairetti
authors.forename: Andrea
authors.initials: A
authors.lastname: Ferrigno
authors.forename: Eleonora
authors.initials: E
authors.lastname: Boncompagni
authors.forename: Isabel
authors.initials: I
authors.lastname: Freitas
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bottiroli