J Korean Soc Ther Radiol Oncol.  2000 Dec;18(4):321-328.

Radiation Effect on NO, NOS and TGF-beta Expressions In Rat Lung

• Oh YT
• Park KJ
• Kil HJ
• Ha MJ
• Chun M
• Kang SH
• Park SE
• Chang SK

Abstract

PURPOSE
NOS2 induce NO production and NO activate TGF-beta. The TGF-beta is a inhibitor of NOS2. If this negative feedback mechanism operating in radiation pneumonitis model, NOS2 inhibitor may play a role in TGF-beta suppression. We planned this study to evaluate the expression patterns of NO, NOS2 and TGF-beta in vivo radiation pneumonitis model.
MATERIALS AND METHODS
Sixty sprague-Dawley rat were irradiated 5 Gy or 20 Gy. They were sacrificed 3, 7, 14, 28 and 56 days after irradiation. During sacrifice, we performed broncho-alveolar lavage (BAL). The BAL fluids were centrifuged and supernatents were used for measure NO and TGF-beta, and the cells were used for RT-PCR.
RESULTS
After 5 Gy of radiation, NO in BAL fluid increased at 28 days in both lung and TGF-beta in left lung at 56 days. NO increased in BAL fluid at 28 days in both lung after irradiation and TGF-beta in right lung at 28-56 days after 20 Gy of radiation. After 5 Gy of radiation, NOS2 expression was increased in right lung at 14 days, in both lung at 28 days and in left lung at 56 days. TGF-beta expression was reduced in both lung at 28 days and increased in left lung at 56 days.
CONCLUSIONS
The proposed feedback mechanism of NO, NOS2 and TGF-beta was operated in vivo radiation pneumonitis model. At 56 days, however, NOS2 and TGF-beta expressed concurrently in left lung after 5 Gy and in both lung after 20 Gy of radiation.

Keyword

Radiation pneumonitis; NO; NOS2; TGF-beta; Radiation

MeSH Terms

Animals
Lung*
Radiation Effects*
Radiation Pneumonitis
Rats*
Rats, Sprague-Dawley
Therapeutic Irrigation
Transforming Growth Factor beta*
Transforming Growth Factor beta