Biochemical and morpho-mechanical properties, and structural organization of rat tail tendon collagen in diet-induced obesity model

We have investigated the impact of obesity on the structural organization, morpho-mechanical collagen fibers from rat tail tendon fascicles (RTTFs). Polarized Raman microspectroscopy showed collagen bands 855, 875, 938, and 960 cm(-1) as well as those 1631 and 1660 cm(-1) were affected chanical properties exhibited an increase in the yield strength from control (CTRL) to high fat (HF) 1.71 and 13.09 +/- 1.81 MPa) (p < 0.01) and ultimate tensile strength (13.12 +/- 2.37 and 18.32 +/- 0.05) with no significant change in the Young's Modulus. During mechanical, the band at 875 cm(-1) most relevant frequency shift (2 cm(-1)). The intensity of those at 855, 875, and 938 cm-1 in HF played a comparable response to mechanical stress as compared to CTRL collagen with no significant changes in the Full Width at Half Maximum. Second harmonic generation technique revealed straightness (0.963 +/- 0.004 and 0.965 +/- 0.003) and ii) significant changes in fibers diameter (1.48 1.52 +/- 0.08 mu m) (p < 0.05) and length (22.06 +/- 2.38 and 29.00 +/- 3.76 mu m) (p < 0.001) between diet, respectively. The quantification of advanced glycation end products (AGEs) revealed an increase carboxymethyl-lysine and total fluorescence AGEs from CTRL to HF RTTFs.