Alterations in plasma biochemical composition in NO deficiency induced by L-NAME in mice analysed by Fourier Transform Infrared Spectroscopy

Abstract

Mouse model of nitric oxide deficiency, induced by prolonged treatment with N -nitro-L-arginine methyl ester (L-NAME) was used for infrared spectroscopy (FTIR) analysis of plasma. L-NAME leads to increased peripheral resistance and systemic hypertension. Classification of spectral response was by principal component analysis (PCA) and linear discriminant analysis (LDA). PCA allowed to separate each animal group showing that FTIR spectra are sensitive to development of NO-deficiency on contrary to blood pressure values indicating hypertension. Globally, the most pronounced spectral alternations were observed in the second and third week of L-NAME treatment indicating that infrared signature of blood plasma can serve as indicator of early and late stages of the disease. The PLS-DA method provided >95% classification accuracy. Spectral features characteristic for L-NAME treatment were mainly associated with an elevated level of proteins accompanied by a decrease of a tyrosine content and changes in lipids/phospholipid concentration. In our work we discuss these changes for which statistically significant differences (p < 0.05 - 0.005) were observed between spectra collected for each time-point of the L-NAME treatment versus control subjects. We demonstrated for the first time that NO-deficiency and hypertension resulted in changes in biochemical profile of plasma that was detected by FTIR spectroscopy.

A possible Fourier transform infrared‐based plasma fingerprint of angiotensin‐converting enzyme inhibitor‐induced reversal of endothelial dysfunction in diabetic mice

“…As PER 10 mg/kg, but not PER 2 mg/kg, improved endothelial function the unsaturation level of plasma fatty acids seemed to reflect endothelial status, and most likely oxidative stress. Interestingly, our analysis of systemic and pulmonary hypertensions indicated a similar decrease of lipid unsaturation level in plasma that could also be relevant to the presence of endothelial dysfunction in these diseases [25,27].…”

“…In summary, our results demonstrated that the combination of chemometric analysis and FTIR spectroscopic signature of the macromolecular vibrations found in 0.5 μL dried plasma films reflected closely metabolic disturbances of diabetes and can possibly be used for a rapid monitoring the metabolic response of the diabetes treatment . However, in contrast to other pathologies, in which pattern of FTIR plasma changes seemed to clearly reflect vascular wall pathology, for example, in NO‐deficient mice or pulmonary hypertension , and could be possibly used for monitoring of vasoprotective treatment, FTIR spectra in diabetes were dominated by massive diabetes‐related metabolical dysfunction that masks and overweighs the subtle endothelial‐related effects. However, in each of these 3 pathologies such as systemic hypertension, pulmonary hypertension and diabetes that are linked to endothelial dysfunction, alterations in the secondary structure of proteins are visible, suggesting that this type of changes may indeed constitute the reliable FTIR‐based fingerprint of endothelial dysfunction.…”

“…Fourier transform infrared (FTIR) spectroscopy to study blood‐based samples is not a new concept and there are several reports showing a usefulness of infrared spectroscopy for diagnosis, monitoring progression of diseases and their treatment by investigation of erythrocytes , leukocytes , platelets , plasma , and serum . Instead of the quantification of a single or a few biomarkers, on which most of the blood tests rely, the total biochemical composition of a sample is analyzed in a single and rapid measurement of plasma IR spectrum including peptides, proteins, lipids, RNA and others.…”

“…Three replicates of each plasma sample (0.5 μL) were manually spotted onto CaF 2 windows, and left to dry in a temperature-controlled laboratory (24 C) for approximately 5 min. A similar approach has been successfully employed in several FTIR studies on plasma and serum [25,27,28,34,[41][42][43][44][45].…”

Fourier transform infrared spectroscopic signature of blood plasma in the progression of breast cancer with simultaneous metastasis to lungs

“…For each plasma sample, three replicates (0.5 μL) were spotted onto CaF 2 windows, and left to dry in a room temperature (24 C) for 5 minutes as optimized in our earlier works [21,[25][26][27]. The samples (in total 47) were randomly selected for spectral measurements to avoid environmental and instrumental factors which could contribute to further analysis.…”