Density Functional Model of Raman Spectra for the Seminiferous Tubules of Hindlimb Unloaded Mice

Abstract

A model Raman spectrum was constructed by using density functional theory (DFT) to track amino acid changes in the seminiferous tubules of hindlimb unloaded (HU) mice. A B3LYP functional with 6-31G* polarization basis sets were used in the calculations. A number of features in the model were comparable to the experimentally obtained spectrum collated with a 785-nm laser from the testicular tissues of the male mice unloaded for two weeks. A comparison of the theoretical and the experimental Raman spectra indicated that hydroxyproline and tryptophan are the major amino acids in the seminiferous tubules. By using Raman spectroscopy, we also confirmed by histological measurement that the same molecules showed depression. The changes in these molecules resulted in the disruption of the testicular seminiferous tubules, resulting in pathological conditions such as epithelial atrophy, tubular shrinkage, and lumen expansion. Our observations indicated that the DFT model of the Raman spectra has the potential to precisely predict and analyze the features of the experimental spectra in the testicular tissues of HU mice.