Preparation and Biodistribution of [67Ga]-Dtpa-Gonadorelin in Normal Rats Publisher



Jalilian AR¹ ; Shanehsazzadeh S² ; Akhlaghi M¹ ; Garousi J¹ ; Rajabifar S¹ ; Tavakoli MB² Show Affiliations
Source: Journal of Radioanalytical and Nuclear Chemistry Published:2008

Abstract

Gonadorelin was successively labeled with [67Ga]-gallium chloride after residulation with freshly prepared cyclic DTPA-dianhydride. The best results of the conjugation were obtained by the addition of 1 mg of a gonadorelin to a glass tube pre-coated with DTPA-dianhydride (0.33 mg) at 25°C with continuous mild stirring for 1 hour. Radio thin layer chromatography showed an overall radiochemical purity of >90% at optimized conditions after labeling. HPLC showed a radiochemical purity more than 95% (specific activity = 400-450 GBq/M). The stability of the radioconjugate was tested in presence of human serum at 37°C. Preliminary in vivo studies in normal rats were performed to determine the biodistribution of the conjugate up to 48 hours. The breast and ovaries uptakes were significantly high in first 15-minute post injection which is in agreement with the other reports regarding the presence of specific GnRH receptors. This tracer can be used in detection of GnRH receptor biodistribution in various diseases and malignancies. © 2008 Springer Science+Business Media, LLC.