Effect of irradiation on microvascular endothelial cells of parotid glands in the miniature pig.
Int J Radiat Oncol Biol Phys
; 78(3): 897-903, 2010 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-20832188
ABSTRACT
PURPOSE:
To evaluate the effect of irradiation on microvascular endothelial cells in miniature pig parotid glands. METHODS AND MATERIALS A single 25-Gy dose of irradiation (IR) was delivered to parotid glands of 6 miniature pigs. Three other animals served as non-IR controls. Local blood flow rate in glands was measured pre- and post-IR with an ultrasonic Doppler analyzer. Samples of parotid gland tissue were taken at 4 h, 24 h, 1 week, and 2 weeks after IR for microvascular density (MVD) analysis and sphingomyelinase (SMase) assay. Histopathology and immunohistochemical staining (anti-CD31 and anti-AQP1) were used to assess morphological changes. MVD was determined by calculating the number of CD31- or AQP1-stained cells per field. A terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay was used to detect apoptotic cells. The activity of acid and neutral Mg(2+)-dependent SMase (ASMase and NSMase, respectively) was also assayed.RESULTS:
Local parotid gland blood flow rate decreased rapidly at 4 h post-IR and remained below control levels throughout the 14-day observation period. Parotid MVD also declined from 4 to 24 hours and remained below control levels thereafter. The activity levels of ASMase and NSMase in parotid glands increased rapidly from 4 to 24 h post-IR and then declined gradually. The frequency of detecting apoptotic nuclei in the glands followed similar kinetics.CONCLUSIONS:
Single-dose IR led to a significant reduction of MVD and local blood flow rate, indicating marked damage to microvascular endothelial cells in miniature pig parotid glands. The significant and rapid increases of ASMase and NSMase activity levels may be important in this IR-induced damage.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Glândula Parótida
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Lesões Experimentais por Radiação
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Células Endoteliais
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Microvasos
Limite:
Animals
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Ano de publicação:
2010
Tipo de documento:
Article