Abstract
Angiogenesis involves many mediators including integrins, and the tripeptide RGD is a target amino acid recognition sequence for many of them. Hindlimb ischemia is a simple and convenient animal model however standardization of the injection procedures in the devascularized and control limb is lacking, thus rendering difficult the interpretation of results. The aim of this investigations was to evaluate neovascularization in a hindlimb murine model by means of ⁹⁹(m)Tc-HYNIC-ß-Ala-RGD. ⁹⁹(m)Tc-HYNIC-RGD analog was prepared using coligands. Ischemia was induced in Wistar rats by double- ligation of the common femoral artery. Radiolabeled RGD was injected after 2h, as well as 1, 3, 5, 7, 10 and 14 days. Uptake was evaluated by planar imaging and biodistribution studies. The highest ratio between ischemia and control was achieved at the 7th day (2.62 ± 0.95), with substantial decrease by the 14th day. For pertechnetate the 7th day ratio was 0.87 ± 0.23. Scintigraphic image confirmed different uptakes. ⁹⁹(m)Tc-HYNIC-RGD analog concentrated in ischemic tissue by the time of widespread angiogenesis and pertechnetate confirmed reduction in blood flow. In this sense, the protocol can be recommended for ischemic models.
Highlights
Several partially overlapping definitions apply to the development of blood vessels
Elevated DvE3 integrin expression has been observed in ischemic tissue of the brain, ophthalmological diseases, and muscles[3]
The highest ratio between ischemic hindlimb and control side was achieved at the 7th day (2.62 ± 0.33), with substantial decrease by the 14th day (0.30 ± 0.02)
Summary
Several partially overlapping definitions apply to the development of blood vessels. Neovascularization is the broad physiological response to ischemia and corresponds to blood flow recovery detected in vivo. Integrins are a notable class of receptor proteins, from the large family of cell adhesion receptors which are involved in cell-extracellular matrix and cell-cell interactions[2] They consist of two transmembrane glycoproteins represented by non-covalently associated Į and ß-units, which are essential for the healing of ischemic lesions. The most common approach for designing a targetspecific 99mTc agent has been to attach a chelating group to a bioactive molecule, resulting in a combined ligand that can form a complex with 99mTc in a reduced oxidation state This procedure is commonly known as a bifunctional approach, and the specific ligands employed as bifunctional chelating agents (BFCAs). The aim of this investigations was the use 99mTc-HYNICß-Ala-RGD as a diagnostic radiotracer to evaluate neovascularization in the extended period of 14 days, in a hindlimb murine model with double arterial ligation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
