Investigating the attenuating effect of telmisartan against radiation-induced intestinal injury using ¹⁸F-FDG micro-PET imaging

Abstract

Background and objective

This study was aimed to investigate the ability of ¹⁸F-Fluro-deoxy-glucose (¹⁸F-FDG)-based micro-positron emission tomography (microPET) imaging to evaluate the efficacy of telmisartan, a highly selective angiotensin II receptor antagonist (ARA), in intestinal tissue recovery process after in vivo irradiation.

Methods

Male Balb/c mice were randomly divided into four groups of control, telmisartan, irradiation, and telmisartan + irradiation. A solution of telmisartan in phosphate-buffered saline (PBS) was administered orally at 12 mg/kg body weight for seven consecutive days prior to whole body exposing to a single sub-lethal dose of 5 Gy X-rays. The mice were imaged using ¹⁸F-FDG microPET at 9 and 30 days post-irradiation. The ¹⁸F-FDG uptake in jejunum was determined according to the mean standardized uptake value (SUVmean) index. Tissues were also processed in similar time points for histological analysis.

Results

The ¹⁸F-FDG microPET imaging confirmed the efficacy of telmisartan as a potent attenuating agent for ionizing radiation-induced injury of intestine in mice model. The results were also in line with the histological analysis indicating that pretreatment with telmisartan reduced damage to the villi, crypts, and intestinal mucosa compared with irradiated and non-treated group from day 9 to 30 after irradiation.

Conclusion

The results revealed that ¹⁸F-FDG microPET imaging could be a good candidate to replace time-consuming and invasive biological techniques for screening of radioprotective agents. These findings were also confirmed by histological examinations which indicated that telmisartan can effectively attenuates radiation injury caused by ionizing-irradiation.

Keywords:

• Ionizing radiation
• radioprotector
• telmisartan
• intestine injury
• ¹⁸F-FDG microPET
• mean standardized uptake value

Acknowledgments

The authors thank Anita Ebrahimpour and Nasrin Seyedpour for their help in histological analysis and microPET imaging.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported financially by a grant from Tehran University of Medical Sciences [grant number: 42235- 30-02-98].

Notes on contributors

Masoomeh Fooladi

Masoomeh Fooladi, PhD, recently graduated with a PhD in Medical Physics, at the Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.

Alireza Shirazi

Alireza Shirazi, PhD, is a Professor of Medical Physics at the Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.

Peyman Sheikhzadeh

Peyman Sheikhzadeh, PhD, is an assistant Professor of Medical Physis at the Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran.

Mahsa Amirrashedi

Mahsa Amirrashedi, PhD, recently graduated with a PhD in Medical Physics from Tehran University of Medical Science and Research Center for Molecular and Cellular Imaging. Her research interests focus on quantitative corrections, image reconstruction, image analysis, and application of deep-learning with a special emphasis on small animal PET/CT imaging.

Fatemeh Ghahramani

Fatemeh Ghahramani, MSc, Master in Medical Physics, radiotherapy specialist at the Radiotherapy-Oncology Center, Yas Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.

Mohsen Cheki

Mohsen Cheki, PhD, is an assistant Professor of Medical Physis at the Department of Medical Imaging and Radiation Sciences, Faculty of Paramedicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Mehdi Khoobi

Mehdi Khoobi, PhD, is an associate Professor of Chemistry at the Department of Radiopharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.