Preparation and stability of the sup 9 sup 9 sup m Tc-HNE sub 2 radiopharmaceutical

and acetone as eluent systems) at different time intervals in solutions of different cysteine concentration. These tests indicated the trans chelation grade of the sup 9 sup 9 sup m Tc metal. In the In vivo evaluations the stability of the sup 9 sup 9 sup m Tc-HNE-2 was obtained when it was realized the biodistribution in normal mice of the balb-c stock. The obtained results show a radiochemical purity of 95.05 % +- 2.81% for the sup 9 sup 9 sup m Tc-DTPA-HNE-2 conjugates and 51.45% +- 3.2% for sup 9 sup 9 sup m Tc-HYNIC-HNE-2 even as tricine as colligand was used. The In vivo and In vitro stability tests of the radio conjugates show that the radio complexes are keeping whole at least during 24 hours (In vitro) time in which passing for half life of the sup 9 sup 9 sup m Tc radionuclide and 30 min (In vivo). Since the radio conjugates prepared with DTPA were obtained with radiochemical purities adequate for its use in scintillography, it is necessary as a future work to realize the biodistribution kinetics as in healthy animals as in models with induced infectious processes. Likewise for obtaining gamma graphic images at different times, from animals with induced infections, with the purpose to determine the radiopharmaceutical effectiveness for detecting infectious centres. (Author) neutrophyll elastase (HNE-2). Likewise, for evaluating its In vivo and In vitro stabilities. The methodology which was followed as first step to conjugate the (HNE-2) peptide with the bi chelating agents HYNIC and DTPA capable to chelate the sup 9 sup 9 sup m Tc metal. Therefore the attachment reactions to the peptide were realized starting from the NHS and HYNIC and the DTPA anhydride in buffer of 0.1 M, pH= 9.0/DMF (10:1) bicarbonates with a molar relation peptide/bi chelating agent 1:5. For the purification of the conjugate the solid phase extraction was used, using the C-18 sep-pak cartridges. The native peptide and the conjugate were characterized by High Performance Liquid Chromatography (HPLC) using a molecular exclusion column for YMC-Pack Diol-60 peptides, phosphates buffer 0.1 M p H= 7.4 at a flux 1.5 ml/min; integrated to a diode arrangement detector to obtain the UV spectra and a radioactivity detector for obtaining the radio chromatograms of the compounds in study, verifying that the different bifunctional agents will be separate appropriately from the peptide, once formed the conjugate peptide, the labelling with sup 9 sup 9 sup m Tc was realized using sodium pertechnetates (NaTcO sub 4) eluted from a sup 9 sup 9 Mo/ sup 9 sup 9 sup m Tc generator and as a reducer agent stannous chloride. The In vitro stability tests were realized measuring the radiochemical purity of the radio peptide in Instant Thin Layer Chromatography with silica-gel (ITLC-SG), NaCl 0.9% A radiopharmaceutical is all substance containing a radioactive atom inside of its structure and what because of its pharmaceutical form, quantity and quality of radiation can be administered in the human beings with diagnostic or therapeutic aims. With the purpose to developing effective radiopharmaceuticals it is necessary to pick carefully the appropriate radionuclide in combination with the In vivo localization and the pharmacon kinetic properties of the carrier molecule. The peptides are designed by the nature to stimulate, regulate or inhibit numerous life functions, they act mainly as information transmitters and activity coordinators of several tissues in the body; it has been found that such substances are present in cells and in the body fluids in quantities extremely small, therefore the peptides have been considered as ideal agents for therapeutic applications. Elastase of human neutrophylls is a 29 kDa protease which is produced in high levels inside the neutrophyll and it is released as response for an inflammatory stimulus in infection/inflammation places. Once it liberated is quickly inhibited by the anti elastase alpha tripsine (HNE-2) peptide. Therefore, the neutrophylls elastase is considered as a target to obtain In vivo images of inflammatory/infectious processes by the intravenous application of sup 9 sup 9 sup m Tc-HNE-2. The objective of this work was to develop a labelling method with sup 9 sup 9 sup m Tc for the inhibitor peptide of the huma