Figure 5

Sepsis was associated with reduced expression and changes in chemical structure of GFB sialic acids. Quantitative analysis of lectin histochemistry at 3 and 7 hours after sham or CLP operation. Reactivity intensity of MAA, SNA and PNA, after treatment with neuraminidase (with and without deacetylation), was significantly lower in CLP compared to sham-operated samples, demonstrating a decrease of sialic acid in septic rats. After mild oxidation-neuraminidase treatment (with and without deacetylation), PNA reactivity intensity was lower in sham-operated than in CLP rats, demonstrating a major amount of sialic acid with acetylic groups in C₇- and/or C₈- and/or C₉- in septic rats. Data from mild oxidation were lower compared to those without mild oxidation for both sham-operated and CLP rats, indicating that some but not all sialic acids were acetylated in C₇-and/or C₈- and/or C₉-. No significant difference between groups was observable in PNA reactivity intensity, after strong oxidation-neuraminidase treatment, with and without deacetylation; for both groups, reactivity intensity was statistically lower when compared to the neuraminidase PNA reactivity with and without mild oxidation, thus indicating that some sialic acids were acetylated in C₉ and linked α-2,3. No difference between 3 and 7 hours was found. (* P <0.05 sham-operated versus CLP same reaction; # P <0.05 mild oxidation versus without oxidation; § P <0.05 strong versus mild and versus without oxidation, panels A and B). CLP, cecal ligation and puncture; MAA, Maackia amurensis agglutinin; PNA, peanut agglutinin (Arachis hypogaea); SNA, Sambucus nigra agglutinin; Neu/PNA, neuraminidase/PNA; KOH/Neu/PNA, deacetylation/neuraminidase/PNA; 1 mM PO/Neu/PNA, mild oxidation/neuraminidase/PNA; 1 mM PO/KOH/Neu/PNA, mild oxidation/deacetylation/neuraminidase/PNA; 44 mM PO/Neu/PNA, strong oxidation/neuraminidase/PNA; 44 mM PO/KOH/Neu/PNA, strong oxidation/deacetylation/neuraminidase/PNA.