A comparative study of artificial ceroid/lipofuscin from different tissue materials of rats.

The artificial ceroid/lipofuscin pigments originated from different organ tissues, including liver, brain, heart, and kidney of rats, and biomaterials were studied with improved fluorometric techniques. With all tissue materials exposed under ultraviolet (UV) light, a series of similar fluorescent colors were observed under microfluorometer. Analogous fluorescence spectra were also demonstrated with a three-dimensional (3-D) front-surface fluorometric technique despite of the tissue differences. Measured with 3-D fluorometry, relatively simple lipofuscin-like fluorophores were observed from the reactions of malondialdehyde (MDA) with critical biological macromolecules, such as bovine serum albumin (BSA) and DNA. Our results demonstrated that the biomaterials from different tissues have a similar fate under accelerated oxidative/carbonyl stresses but may be differentiated by a fluorescence intensity ratio.

In situ estimation of the entire color and spectra of age pigment-like materials: application of a front-surface 3D-fluorescence technique.

Fluorescent characteristics of age pigment-related materials were re-examined with improved techniques. A series of fluorescent colors, from blue to yellow-red were observed in artificial ceroid/lipofuscin. A front-surface accessory attached to a spectrofluorometer was found very useful in studying the age pigment-like aggregates directly in its solid state. With a three-dimensional (3D)-fluorescence measurement, in addition to the front-surface application, entire fluorescence spectra of artificial ceroid/lipofuscin both in extractions and in non-extractable tissues were obtained. When the front-surface 3D-scan technique was applied to estimate collagen-related age pigments of rat-tails in situ, a dynamic process of age-related protein deterioration accompanied with age pigment development was recorded. The front-surface 3D-fluorescence technique introduced in this study may be used as a practical and effective tool in studying in situ pigment alterations during aging process.