The erythrocyte membrane lipidome profile in healthy dogs and changes in dogs with diabetes mellitus and chronic enteropathy

Analysis of red blood cells (RBC) membrane lipidome is a powerful diagnostic tool for the follow-up of the membrane remodeling under physiological and pathological conditions in humans, however a systematic study in dogs has not yet been established. The aim of this study was to compare RBC membrane lipidome profiles among healthy dogs (HD, n=17), dogs with diabetes mellitus (DM, n=7) and dogs with chronic enteropathy (CE, n=6). RBC were isolated from EDTA-treated blood and fatty acid analyses were carried out by gas chromatography of the corresponding methyl esters (FAME). In HD, saturated and monounsaturated fatty acids (SFA and MUFA) and ω6 levels were similar, while the ω3 values showed a wider variability (mean 1.67%; SD 0.91%) probably due to the individual dietary variations. When compared to HD, the CE dogs had decreased levels of palmitic (p<0.01) and higher stearic acid (p<0.01). In DΜ dogs lower levels of ω6 were observed (p<0.05) while ω3 levels were increased (p<0.05). The MUFA levels differ in the two pathological conditions: higher palmitoleic and oleic in DM (p<0.01), while lower palmitoleic (p<0.05) and vaccenic (p<0.01) in CE. The SFA-MUFA pathway shows significant involvement in canine diabetes mellitus, with a higher palmitic-palmitoleic and palmitic-oleic transformations due to an accelerated delta-9 desaturase enzymatic activity. On the other hand, the increased levels of stearic and decreased palmitoleic and vaccenic acid in CE dogs suggest an activation of elongation pathway, leading to profound changes of membrane fluidity and permeability properties. In conclusion, these preliminary data indicate that erythrocyte membrane lipidome of dogs may be successfully applied in veterinary medicine, providing important information of different profiles under normal and pathological conditions.