engleski

FTIR Spectroscopy Reveals Molecular Changes in BPC 157 Treated Blood Vessels

From the rats treated with stable gastric pentadecapeptide BPC 157 (10ng/kg ip) or saline (5ml/kg ip) at 5 min before sacrifice, the spectra of thoracic aorta tissue samples were compared. From each rat, 20 samples were cut and FTIR spectra were recorded. Vibrational spectra of the samples were recorded with a Perkin-Elmer Spectrum GX spectrometer equipped with liquid N2 refrigerated Mercury Cadmium Telluride (MCT) detector. Data were acquired in 450 - 4000 cm-1 spectral range, in transmission mode with a resolution of 4 cm-1. First, all recorded spectra were baseline corrected and normalized. Then we utilized the principal component analysis (PCA) to examine the possibility of separating BPC treated and control samples on a PCA score-score graph. Using 100 spectra of BPC treated and 100 spectra of control samples, a PCA model was made. As seen in Figure 1, there is a clear distinction, mostly due to the PC1 score, between spectra of BPC treated (red) from the control group (green). To identify the parts of FTIR spectra that contributed the most to the separation between BPC treated and the control group of spectra differential spectrum was calculated and compared with PC1 loadings. Differential spectrum and PC loadings show that main bands responsible for separation of the BPC treated and control sample spectra are in the range from 930-1200 cm-1, then vibrational bands at 1660 cm-1, 1730 cm-1, 1120 cm-1 and in the range from 2840 – 3090 cm-1. In the first range, there are three vibrational bands at 968 cm-1, 1087 cm-1 and 1240 cm-1 that belong to P-O symmetric and asymmetric vibrations in nucleic acids respectably, and vibrational band 1170 cm-1 that belongs to C-O and C-O-C stretching vibrations of carbohydrate. The vibrational band at 1660cm-1 belongs to amid I stretching vibrations of proteins, and the last range of spectral lines belongs to C-H symmetric and asymmetric C-H, C-H2 and C-H3 vibrations in lipids. The line at 1730 cm-1 that is very pronounced in control group spectra is C-O symmetric vibration in fatty acids. Most prominent difference between BPC treated and control group was observed region of C-H vibrations of lipids and vibrational line at 1730 cm-1 of fatty acids. Thus, different FTIR spectra evidenced that BPC treatment causes changes of the tissue at molecular level.

BPC 157 ; FTIR Spectroscopy ; blood vessel

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