RECOGNITION OF N-ACETYLGLUCOSAMINE (GLyNAc) AND POLY-N- ACETYLLACTOSAMINE RESIDUES IN VESSELS OF THE RAT PINEAL GLAND RECONOCIMIENTO DE RESIDUOS DE N-ACETILGLUCOSAMINA (GLyNAc) Y POLI-N-ACETILLACTOSAMINA EN VASOS DE LA GLÁNDULA PINEAL DE RATAS

In neurohistochemistry the lectins are considered profitable biomarkers of glycoconjugates found in the extracellular space or at the cell surface. Glycoconjugates (glycoproteins and glycolipids) can be considered mediators of differentiation and growth during the maturation of the central nervous system (De Grauw & Liwricz, 1986). The lectins recognize specific residues of sugars or their nitrogenated forms (Rüdiger, 1998) and the success of lectins in histology lies in the fact that these molecules can be directly conjugated to a label visible by both light and/or electron microscopy (Danguy et al., 1988; Gabius et al., 1998). The tomato lectins – Lycopersicon esculentum (LEL) used in this study has binding sites that recognize specific sugar residues as N-acetyl-glucosamine (GlyNAc) and polyN-acetyl-lactosamine. Specifically in the brain the LEL has been used to as selective microglial marker (Moffett et al., 1997; Dalmau, 2003) but the LEL has been reported to bind to polyN-acetyl-lactosamine residues in other different cells like as on endothelia (Whyte et al., 1993; Moffett et al., Fakla et al., 1998). This specificity of the LEL in to stain endothelia reinforced the purpose of this paper to study a presumptive pattern for the localization of these residues in the pineal gland vessels during the development as well as in the adults animals through the binding of the biotinylatedLEL.