Modulation of β-adrenergic receptor in rat lung after gamma irradiation.
OBJECTIVE
To study the effect of γ irradiation on β-adrenergic receptors of the lung.


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 60Co γ irradiation. 125I-labeled iodopindolol (125I-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.
Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China.
Yong-Gang
YG
Qiang
Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China.
Yong-Hua
YH
Liao
Department of Radiation Oncology, Guangzhou Medical University, Guangzhou, Guangdong, China.
Xiu-Ping
XP
Zhang
Department of Radiation Oncology, Guangzhou Medical University, Guangzhou, Guangdong, China.
Jian
J
Li
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.
Zheng
Z
Huang
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000526:Alprenolol / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D005260:Female; D005720:Gamma Rays; D007700:Kinetics; D008168:Lung / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*
D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; C045331:bromoacetylalprenololmenthane; D000526:Alprenolol
<formula>^{60}</formula>Co γ radiation; lung; β-adrenergic receptor