Fluorescence spectroscopy as tool for bone development monitoring in newborn rats

Autofluorescence of the mandible and femur bones taken from newborn rats (7-, 14- and 28-day old) was studied. Endogenous fluorophores were excited with 231 nm, 291 nm, 340 nm and 360 nm wavelengths. Modifications in content and microenvironment of both noncolagenous and collagenous constituents of bone tissue as well as metabolic coenzymes during the bone formation with age were reflected in fluorescence emission spectra. The increase of emission from peptide bonds and tryptophan residues was noted with rat age while for collagen and metabolic coenzymes at the first 2 weeks only. After maternal administration of indinavir the changes in fluorescence intensity and shifts in position of peak maximum were found. The distinct drop of emission from peptide bonds and tryptophan residues in studied bones was detected. In the case of collagen and metabolic coenzymes the red shift of peak maximum was revealed. Fluorescence spectroscopy could be used to follow bone development in newborn rats and effect of maternal indinavir administration on offspring.