en General General Original Research: Basic Science in Medicine Original Research: Basic Science in Medicine The life cycle of the American trypanosome, Trypanosoma rangeli, in its invertebrate host, Rhodnius prolixus, is completed by invasion into the insect salivary glands. As a prerequisite, there is an initial recognition of the salivary gland receptors for the adhesion/invasion by T rangeli. Therefore, the purpose of this study was to investigate the putative receptor molecules on either the salivary gland or parasites surfaces, which mediate the adhesion/invasion. Initially, the possible agglutination activity ofT rangeli epimastigotes against blood cell was examined. Then, in order to investigate the role of any receptor ligands on the surface of T rangeli in adhesion/invasion of the parasite, GlcNAc was preferentially used to isolate a ligand protein. A 60kDa protein bound to the GlcNAc column and was isolated from T rangeli (Tr-60) and the purity of this protein was confirmed by reverse phase HPLC. Tr-60 also exhibited a potent parasite inhibitory effect indicating that this protein (most probably a glycoprotein) may act as a ligand receptor. In vivo, the development and invasion of T rangeli into the salivary gland was not interfered with by the presence of a sugar inhibitor of the R. prolixus hemolymph lectin Tlypanosoma rangeli, Rhodnius prolixus, Salivary glands,P roteins, attachment. 159 166 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-96&slc_lang=en&sid=1 HR BASSERI hamid_basseri@hotmail.com" hamid_basseri@hotmail.com 20031947532846003586 20031947532846003586 Yes the Department of Medical Entomology. School of Public Health, Tehran University of Medical Sciences, P0. Box 14155-6446. Tehran, Iran NA RATCLIFFE 20031947532846003587 20031947532846003587 No Biomedical and Physiological Research Group, School o/Biological Sciences, University o/Wales Swansea, Singleton Park. Swansea SA2 8PP United Kingdom