Figure 1.
Representative photomicrographs of thyroid histology in the control, ALA, RT and ALA + RT groups after radiation.
Hematoxylin-eosin staining was performed on cross sections of the thyroid glands. Irregular-sized, smaller follicles than in the control group are noted in addition to inflammatory cell infiltration in the interfollicular area in the irradiated thyroid. Follicles of the ALA + RT group are more normal in size than those of the irradiated rats. CTL, control. RT, irradiated. ALA, ALA only. ALA + RT, received ALA before irradiation. Scale bar, 100 µm.
Figure 2.
Representative photomicrographs of thyroid histology in the control, ALA, RT and ALA + RT groups after radiation.
Masson's trichrome staining was performed on cross sections of the thyroid glands. There was severe fibrosis in the interfollicular space and interfollicular edema was present in the irradiated rat thyroid on days 4 and 7 post-radiation (RT). Irradiation-induced histological changes were attenuated by ALA (ALA + RT). CTL, control. RT, irradiated. ALA, ALA only. ALA + RT, received ALA before irradiation. Scale bar, 100 µm.
Figure 3.
The percentage of three size-classes of the follicles.
Follicles were divided into three categories based on their size: small (18–30 µm in diameter), medium (31–60 µm), and large (>60 µm). In the irradiated rats (RT), there occurred a statistically significant increase in the quantity of small and medium follicles compared to in the control and ALA-treated irradiated rats (ALA + RT). Small follicles were more common in the irradiated rats (RT), and greater numbers were observed on day 7 post-radiation compared to day 4. Small follicles in ALA-treated irradiated rats (ALA + RT) were less frequent than in irradiated rats (RT). (CTL, control; ALA, ALA only; RT-D4, Irradiated rats on day 4; RT-D7, Irradiated rats on day 7; ALA + RT-D4, ALA-irradiated rats on day 4; ALA + RT-D7, ALA-irradiated rats on day 7) (*P<0.05, §P<0.01).
Figure 4.
A. Representative photomicrographs of thyroid histology in the control, ALA, RT and ALA + RT groups after radiation.
PAS staining was performed on cross sections of thyroid gland tissue. Follicles in the control rats were of regular size and had intensely stained colloid, indicating a low activity index. Follicles in the ALA-treated rats (ALA) without irradiation show similar degrees of colloid to the control group. The follicles were filled with less intensely stained colloid and were smaller than those in the control group, indicating a higher activity index. The follicles were filled with dense colloid similar to the controls in the ALA-treated irradiated rats. CTL, control. RT, irradiated. ALA, ALA only. The ALA + RT group received ALA before irradiation. Scale bar, 100 µm. B. PAS-positive colloid density. The PAS-positive density of the colloid in irradiated rats (RT) was decreased significantly compared with in all other groups. ALA-treated rats (ALA) showed a similar density of PAS-positive colloid to control rats (*P<0.05, §P<0.01).
Figure 5.
TGF-ß1 immunohistochemical staining of cross sections of rat thyroid gland tissue.
The immunohistochemical localization of TGF-ß1 appears as dark-brown staining. TGF-ß1 expression was more intense in the follicular epithelium of the irradiated rats (RT) (thyrocytes strongly express TGF-ß1). The signals were stronger on day 7 than day 4. TGF-ß1 expression was less intense in the ALA group compared to the RT group. CTL, control. RT, irradiated. ALA, ALA only. ALA + RT, received ALA before irradiation. Scale bar, 100 µm.
Figure 6.
Immunohistochemical staining for 8-OHdG and MDA.
8-OHdG-positive signals were much dense at day 4 than day 7 after radiation (A). Expression of MDA was localized at the stromal area in radiation groups (B). Both signals were decreased in ALA-treated groups. Scale bar, 100 µm.