Clinical evaluation of GLY-GLY-Alanine and same group peptides labeled with 99mTc
Loading...
Files
Date
2000-10
Journal Title
Journal ISSN
Volume Title
Publisher
Turkish Atomic Energy Authority
Abstract
In this study, seven different (six of them with -N H and one of them with -NHSH side chain)
peptides (Gly-l-Hystidine, Gly-l-Methionine, Gly-l-Tyrosine, Gly-Gly-l-Alanine, Gly-l-leucine
amide, Gly-l-Glutamic acid, Gly-l-Gly-amide) were selected. For the positive control,
tetraglycin (Gly-Gly-Gly-Gly) was chosen and for each of them, " mTc labeling studies have
been performed using both direct and ligand exchange methods. Among these peptides, two of
them (Gly-Gly-l-Alanine (GGA) and Gly-l-leucyl amide(GLA)) were labeled with the yields
that were close to the USP acceptance criterions. Quality control has been performed by reverse
phase HPLC analysis method with the use of a Beckman-Gold Radio-HPLC system. Latter on,
radiopharmaceutical distribution and organ uptake characteristics of these peptides (" mTc-GGA
and 99mTc-GLA) on rabbits were studied by using gamma camera imaging technique. Also,
animal bio-distribution with GGA and inflammation imaging studies with GLA on rat models
with sterile inflammation have been performed. Results indicated that in direct radio-labeling
method developed for the small molecule peptides, labeling yields and retention times for " mTcGGA and " mTc-GLA radio-complexes were % 75.09 at 12 minute and % 74.20 at 17.5
minutes, respectively in reverse phase Radio-HPLC analysis. For the rest of the five peptides,
direct and ligand exchange labeling methods were unsuccessful to produce a radio-labeled
peptide that has an acceptable yield in terms of the radiopharmaceutical quality.
Gamma camera imaging studies have indicated that both of the peptides ( " mTc-GGA and " mTcGLA) have demonstrated remarkable rapid blood clearance and dynamic discharge through
kidneys. It is possible to say that based on the initial images and renogram data, dynamic kidney
imaging can be obtained right after 30 minutes of the application and static kidney scintigrams
can be taken by performing late imaging with " mTc-GGA radio-peptide complex. On the other
hand, " mTc-GLA complex may have a potential use especially for very clear dynamic kidney
and infection imaging studies. In bio-distribution study on rabbits, in terms of radio-peptide
retention, the most important organ and body fluid samples were taken and then counted (first
with collimated and then with non-collimated gamma camera counting system) with
TENELLEC well type detector system. When compared to the other body organs, it was
observed that kidneys showed the most active retention and the most of the applied radiopeptide were thrown out through urine. Also, In the infection imaging studies on mouse models with colitis using the same radio-labeled peptides, 99mTc-GLA proved to be more appropriate as indicated by the scintigrams.
Description
I. Avrasya Nükleer Bilimler ve Uygulamaları Konferansı : 23-27 Ekim 2000. İzmir, Türkiye.
Keywords
Gly-Gly-Alanine, Clinical evaluation, Klinik değerlendirme, Peptides labeled, Etiketli peptitler, Tc-99m / Technetium-99m, Teknesyum-99m
Citation
Taner, M. S., Özdemir, D., Duman, Y., (2000). Clinical evaluation of GLY-GLY-Alanine and same group peptides labeled with 99mTc. I. Eurasia Conference on Nuclear Science and Its Application, Presentations, Vol 1, (s. 434-441). 23-27 October 2000. İzmir, Turkey.