Morphometrical study of polysialylated neural cell adhesion molecule positive cells in rat pups hippocampus following induction of seizure during pregnancy

The polysialylated neural cell adhesion molecule [PSA-NCAM] is expressed in developing brain. Fetal brain damage is caused by different conditions such as seizure and hypoxia. The present study was designed to investigate the effect of maternal seizures on the number of PSA-NCAM positive cells in pup's hippocampus. Female Wistar rats were divided into four groups: [a] kindled rats which received PTZ [40 mg/kg, i.p.] during pregnancy from embryonic day 14-19 [E14-E19] every 48 h, [b] kindled rats which did not receive PTZ during pregnancy, [c] non-kindle, pregnant rats which received PTZ injection [40 mg/kg, i.p.] during pregnancy from E14 to E19 every 48 h, and [d] non-kindle, pregnant rats which received injection with an equal volume of normal saline as sham controls. At postnatal day 14 [PD[14]], rat pups were perfused, and their brain were fixed, embedded and coronal sections stained by immunohistochemistry method. The number of PSA-NCAM positive cells per unit area in the pup's hippocampus was counted. The number of PSA-NCAM positive cells in the CA1, CA3, and DG fields of pup's hippocampus, which was obtained from mothers who experienced PTZ injection during pregnancy, was decreased approximately 2.6 [P = 0.001], 2 [P = 0.001], and 2.1 [P = 0.001] times compared with non-PTZ treated maternal groups, respectively. Our study showed that maternal seizures reduced the number of neurons and also PSA-NCAM positive cells per unit area in the offspring hippocampus that it may cause impairment in hippocampal functions

Lectin histochemical study of vasculogenesis during rat pituitary morphogenesis

The aim of this study was to investigate glycoconjugates distribution patterns as well as their changes during the course of pituitary portal vasculogenesis and angiogenesis. Formalin fixed paraffin sections of 10 to 20 days of Sprague Dawly rat fetuses were processed for histochemical studies using four different horseradish peroxidase [HRP] conjugated lectins. Orange peel fungus [OFA], Vicica villosa [VVA], Glycine max [SBA] and Wistaria floribunda [WFA] specific for alpha-L-Fucose, D-Gal, alpha, beta-D-GalNAc and D-GalNAc terminal sugars of glycoconjugates respectively. Our finding indicated that adenohypophysal cells reacted with OFA on gestational day 10 E[10] and increased progressively to E[14]. Staining intensity did not change from days 14 to17, then after increased following days to E[20] significantly [P< 0.05]. A few cells around Rathke's pouch reacted with VVA on E[13], increased to E[14] and decreased significantly afterward [P< 0.05]. Reaction of some cells around Rathke's pouch reacted with SBA on E[14]. This visible reaction was the same as E[18] and decreased later [P< 0.05]. Many cells around Rathke's pouch reacted with WFA on E[13] and increased on E[14] and E[15] and decreased thereafter [P<0.05]. Reactions of OFA and other tested lectins with endothelial cells around Rathke's pouch and developing pars distalis were different. These results suggest that embryonic origin of hypophiseal pituitary portal [HPP] system endothelial cells are not the same and our finding also indicated that glycoconjugates with terminal sugars alpha-L-Fucose, D-Gal, alpha, beta-D-GalNAc may play critical role[s] in cell interactions and tissue differentiations such as vasculogensis and angiogenesis as well as other developmental precursors in formation of the pituitary gland

Distribution of specific glycoconjugates in early mouse embryonic notochord and paraxial mesenchyme

It is well known that glycoconjugate components of the cell surface and extracellular matrix, play an essential role[s] in many developmental phenomena such as cell differentiation, migration, and cellular interactions. The purpose of this study was to investigate distribution of this macromolecules during differentiation of the notochord and paraxial mesoderm. Formalin fixed paraffin sections of 9 to 16 days of BALB/c mouse embryos were processed for histochemical studies using four different horseradish peroxidase conjugated lectins including wheat germ agglutinin [WGA], Griffonia simplicifolia [GSA1-B4], Arachis hypogaea [PNA] and Lotus tetragonolobus [LTA], specific for sialic acid, galactose, N-acetylgalactosamine [GalNAc] and fucose terminal sugar, respectively. Our results showed that in primordial of the developing vertebrae PNA sensitive glycoconjugate appeared on gestational day 13 and increased to gestational day 15 significantly [P<0.05] and disappeared later. GSA1-B4 revealed no reaction and LTA and WGA reactions were observed only in notochord. Among the lectins that were used in this study, only PNA showed continuous and strong reaction just during gestational day 13 to 15. This finding suggests that PNA temporally regulated changes occurred during early vertebral development in mouse embryos and probably their specific terminal sugar plays a key role[s] during prechondrogenic vertebrae

Lectin-binding patterns in the microenvironment of the mouse developing T-cells

Glycoconjugates and their programmed changes during the course of development in the cell-surface as well as in the extracellular matrix, are known to affect cell differentiation, cellular interaction and other developmental phenomena during embryogenesis. The purpose of this study was to localize N-acetylgalactosamin as well as fucose-containing glycoconjugates in situ during thymus development. Staged embryos or thoracic segments were fixed and processed for lectin histochemistry studies. Five microns paraffin-embedded sections were incubated with horseradish peroxidase conjugated lectins from Dolichos biflorus and Aleuria aurantia specific for N-acetylgalactosamine and fucose, respectively. Our results revealed unique reaction of T-cells with Dolichos biflorus and the presence of a fucosylated glycoconjugate in microenvironments of the developing thymus including extracellular matrix and developing Hassall bodies. The time and distribution of staining with these two lectins suggest that fucosylated glycoconjugates and N-acetylgalactosamin terminal sugars may play significant role in intrathymic microenvironment that might cause differentiation of T-lymphocytes

Unique carbohydrate appearance of the floor plate during early neurolation

During early neurogenesis, the floor plate plays an essential role[s] in the differentiation of the ventral portion of neural tube. In this study, we detected the specific distribution of unique glycoconjugate during the floor plate differentiation. Formalin fixed paraffin sections of BALB/c mice [10-14 embryonic days] were processed for histochemical studies using horseradish peroxidase-labelled N-acetylgalactosamine [GalNAc] sensitive lectins. Histochemical analysis has revealed the presence of unique Wisteria floribunda [WFA]-sensitive glycoconjugate reaction in the floor plate area and surrounding extracellular matrix. Weak reaction also was observed in the outer surface of the basal zone of the neural tube. Extensive differences among the GalNAc lectins were demonstrated during the sensitive time of motoneuron differentiation. There was no reaction with other tested GalNAc lectins. The duration and distribution of WFA lectin reactions suggest that these molecules may play a key role[s] in tissue interactions and subsequent formation of the adjacent tissues including floor plate and basal plate differentiation during critical morphogenic period. Furthermore, our findings indicate that among considered early neuronal morphogenic [embryonic] days, WFA reactions were increased and expanded near the end of gestation period