Presence of N-acetylneuraminic acid in the lung during postnatal development

Sialic acids, particularly N-acetylneuraminic acid (Neu5Ac), are present as terminal components of rich and complex oligosaccharide chains, which are termed glycans, and are exhibited on the cell surfaces, especially on epithelial cells. Crucial in the ‘social behavior’ of the cell, sialic acids play vital roles in many physiological and pathological phenomena. The aim of the present study was to separate, identify, and quantify Neu5Ac in purified lung membranes from 4-, 14-, and 21-day-old animals, followed by the statistical analysis of thes e results with our previously reported data (0-day-old and adult results). Complementary, ultrastructural methodologies were used. The differences in the Neu5Ac values obtained across the examined postnatal-lung development relevant ages studied were found to be statistically significant. A substant ial increase in the mean level of this compound was found during the period of ‘bulk’ alveolarization, which takes place from postnatal day 4 to 14 (P4-P14). The comparison of the mean levels of Neu5Ac, during microvascular maturation (mainly between P12 and P21), reveals that the difference, al though statistically significant, is the least significant difference among all the pair-wise differences between the developmental stages. The presence of sub-terminal N-acetylgalactosamine (GalNAc)/Galactose (Gal) residues with terminal sialic acids on the bronchioloalveolar cell surfaces was conf irmed using lung ultra-thin sections of adu...
Source: European Journal of Histochemistry - Category: Biomedical Science Authors: Source Type: research