ABSTRACT
Selectins belong to the family of adhesion molecules that recognize sugars as ligands through their Carbohydrate Recognition Domain [CRD]. There are three types of selectin: the L-selectin [CD62L], which is constitutively expressed by most leukocyte populations, the P-selectin [CD62P] is found on activated platelets and endothelial cells, and the E-selectin [CD62E] expressed by activated endothelial cells. These three molecules exhibit high homology in their structures. Selectin-ligand interactions are among the mos t s tudied prote in- glycan interactions in biology. The selectins and theirs ligands are involved in regulating inflammatory and immunological events that occur at the interface of the bloodstream and vessel walls. Their molecular partners are surface glycoconjugates harboring groups of the sialyl-Lewis antigens. This review presents an inventory of our current knowledge on the structures and functions of selectins and their ligands. We also provide an update on their involvement in pathophysiological processes, especially during inflammation and tumor development
ABSTRACT
Ocytocin and vasopressin are two nonapeptides of the hypo thalamo-post-hypophysary system. They are isolated and purified from dromedary post-hyphophysis, freshly collected in the meat centers of the south of Tunisia. The use of three chromatographies steps were found to be essential in obtaining high Pure hormones Theses steps cousist in a sephadex G25 gel filtration and two successive High performance liquid chromatographies H.P.L.C The analysis of the two hormones by thin layer chromatography and Radioimmunoassays and the identification of the amino-acid composition demonstrate that camel vasopressin is a 8 arginin vasopressin but ocytocin is identical to the other hormones isolated from different animal species