Effects of chronic immobilization stress on biokinetics and dosimetry of 67 Ga in a murine model

Effects of chronic immobilization stress on biokinetics and dosimetry of 67 Ga in a murine model:

Abstract

The aim of this work is to determine the effect of chronic immobilization stress on kinetics and dosimetry of ⁶⁷Ga in a mouse model. A control group (CG) and a stress group (SG), each with 15 mice, were included in the study, and the latter group was subjected to a chronic immobilization stress model 2 h daily for 14 consecutive days. At day 13, ⁶⁷Ga-citrate was administered intraperitoneally (11.24 ± 0.44 MBq) to each mouse. Then, sets of three mice were obtained sequentially at 24, 36, 48, 60 and 72 h, in which the radionuclide activity was measured with an activity counter. The ⁶⁷Ga biokinetic data showed a fast blood clearance in the SG, with a mean residence time of 0.06 h. The calculated mean radiation absorbed doses were: liver (2.45 × 10⁻⁰³ Gy), heart (3.17 × 10⁻⁰⁴ Gy) and kidney (1.88 × 10⁻⁰⁴ Gy) in the SG. The results show that stress reduced weight gain by approximately 13% and also increased adrenal gland weight by 26%. On the other hand, chronic stress accelerates ⁶⁷Ga clearance after 24 h compared to normal conditions. It is concluded that murine organisms under chronic immobilization stress have higher gallium-67 clearance rates, decreasing the cumulated activity and absorbed dose in all organs.