Affiliations: Department of Experimental Nuclear Medicine, Guangzhou
Medical University, Guangzhou, Guangdong, China | Department of Radiation Oncology, Guangzhou Medical
University, Guangzhou, Guangdong, China | School of Photonics and Electronic Engineering, Fujian
Normal University, Fuzhou, Fujian, China | Department of Radiation Oncology and Electronic
Engineering, University of Colorado Denver, Denver, CO, USA
Note: [] Corresponding authors: Yong-Gang Qiang, Department of
Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou,
Guangdong, China. E-mail: yonggangqiang@21cn.com, and Zheng Huang, School of
Photonics and Electronic Engineering, Fujian Normal University, Fuzhou, Fujian,
China. E-mail: zheng_huang@msn.com
Abstract: OBJECTIVES: To study the effect of γ irradiation on β-adrenergic receptors of the lung. MATERIALS AND METHODS: Healthy Sprague-Dawley rats were used as an animal model. Cell membrane proteins of
lung tissue were harvested after the whole lung received 20 Gy of ^{60}Co
γ irradiation. ^{125}I-labeled iodopindolol (^{125}I-IPIN) was used
as a ligand of β-adrenergic receptors. The numbers of the β-adrenergic receptors were determined by
radioligand-receptor binding assay
(RBA). Data were compared with irreversible blockage using antagonist
bromoacetylalprenololmenthan (BAAM). RESULTS: The post-radiation RBA assay showed that the number of β-adrenergic receptors in lung tissue
decreased at a steady rate. It decreased to 48% of the normal level at the
15th day after irradiation. At 40 days after radiation the level of
β-adrenergic receptors started to increase at a steady rate and reached
to the normal level around 70 days after radiation. There were significant
differences in receptor synthesis, degradation and regeneration rates between
irradiation group and BAMM group. CONCLUSIONS: The whole lung irradiation could severely affect the levels of β-adrenergic receptors.
The potential clinical implications of radiation-induced changes of β-adrenergic receptors warrant further investigation.
