Radioprotective Effects of Granulocyte-Colony Stimulating Factor in the Jejunal Mucosa of Mouse

Ryu, Mi Ryeong; Chung, Su Mi; Kay, Chul Seung; Kim, Yeon Shil; Yoon, Sei Chul

Abstract

PURPOSE: Granulocyte-colony stimulating factor (G-CSF) has been widely used to treat neutropenia caused by chemotherapy or radiotherapy. The efficacy of recombinant human hematopoietic growth factors in improving oral mucositis after chemotherapy or radiotherapy has been recently demonstrated in some clinical studies. This study was designed to determine whether G-CSF can modify the radiation injury of the intestinal mucosa in mice.
MATERIALS AND METHODS
One hundred and five BALB/c mice weighing 20 grams were divided into nine subgroups including G-CSF alone group (I : 10 microgram/kg or II : 100 microgram/kg), radiation alone group (7.5 or 12 Gy on the whole body), combination group with G-CSF and radiation (G-CSF I or II plus 7.5 Gy, G-CSF I or II plus 12 Gy), and control group. Radiation was administered with a 6 MV linear accelerator (Mevatron Siemens) with a dose rate of 3 Gy/min on day 0. G-CSF was injected subcutaneously for 3 days, once a day, from day -2 to day 0. Each group was sacrificed on the day 1, day 3, and day 7. The mucosal changes of jejunum were evaluated microscopically by crypt count per circumference, villi length, and histologic damage grading.
RESULTS
In both G-CSF I and II groups, crypt counts, villi length, and histologic damage scores were not significantly different from those of the control one (p>0.05). The 7.5 Gy and 12 Gy radiation alone groups showed significantly lower crypt counts and higher histologic damage scores compared with those of control one (p<0.05). The groups exposed to 7.5 Gy radiation plus G-CSF I or II showed significantly higher crypt counts and lower histologic damage scores on the day 3, and lower histologic damage scores on the day 7 compared with those of the 7.5 Gy radiation alone one (p<0.05). The 12 Gy radiation plus G-CSF I or II group did not show significant difference in crypt counts and histologic damage scores compared with those of the 12 Gy radiation alone one (p>0,05). Most of the mice in 12 Gy radiation with or without G-CSF group showed intestinal death within 5 days.
CONCLUSION
These results suggest that G-CSF may protect the jejunal mucosa from the acute radiation damage following within the tolerable ranges of whole body irradiation in mice.