Eighteen healthy newly weaned SD rats, half male and half female, were randomly divided into Control group(gavaged with 10 mL/kg
normal saline), NaAsO_2-treated group(gavaged with 10 mg/kg NaAsO_2), Active VD(
calcitriol) intervention group(gavaged with 10 mg/kg NaAsO_2 and 1.0 μg/kg
calcitriol was given by gavage along with NaAsO_2 administration after 12 weeks), all rats were administered 6 days a week for 36 weeks and weighed every week.
Enzyme-linked
immunosorbent(ELISA) was used to detect the secretion levels of 25(
OH)D_3 and
hyaluronic acid(HA),
laminin(LN), type Ⅲ pre-
collagen amino-terminal
peptide(PⅢNP), type Ⅳ
collagen(COL-Ⅳ) in the serum of rats in each group; HE staining was used to observe the basic pathological changes of liver tissues in each group, Masson and Sirius Red staining were used to observe the
fibrosis and
collagen deposition of liver tissues in each group; Western Blot was used to detected the
protein levels of
fibrosis-related markers α-smooth actin(α-SMA), transforming growth factor-β1(TGF-β1) and
Vimentin in each group.
RESULTS: After 36 weeks of NaAsO_2 exposure, the weight of rats was significantly decreased compared with the control group, and the weight of female rats after
calcitriol intervention was significantly increased compared with NaAsO_2-treated group(P<0.05). The result of liver coefficient showed increasing in NaAsO_2-treated group compared with the control group, while decreasing in
calcitriol intervention group compared with NaAsO_2-treated group, and the difference was statistically significant in female rats. ELISA assay showed that compared with the control group((550.21±29.16) ng/L), the serum level of 25(
OH)D_3 in NaAsO_2-treated group((436.82±74.37) ng/L) was significantly decreased(P<0.05), while the serum level of 25(
OH)D_3 was significantly higher in
calcitriol intervention group than that of NaAsO_2-treated group(P<0.05). HE staining found that, compared with the control group, the liver tissue of rats in NaAsO_2-treated group showed abnormal morphology, the liver tissue was structurally disordered, false lobules and fat vacuoles were also increased. Masson and Sirius Red staining also revealed abnormal hepatic lobule structure, enlarged and deformed portal area and abundant
collagen fiber deposition in NaAsO_2-treated group. Further analysis showed that the positive staining area of
collagen deposition in liver tissue of rats exposed to NaAsO_2 increased significantly compared with the control group(P<0.05). Those above changes in
calcitriol intervention group were significantly alleviated compared with NaAsO_2-treated group(P<0.05). Western Blot analysis showed that the
protein levels of α-SMA, TGF-β1 and
Vimentin were obviously higher in NaAsO_2-treated group(1.12±0.21, 1.12±0.26, 1.31±0.15) than that in the control group(0.57±0.10, 0.64±0.13, 0.72±0.16)(P<0.05). In addition, the serum levels of HA, LN, PⅢNP and COL-Ⅳ in rats exposed to NaAsO_(2 )((87.92±9.67), (89.04±11.91), (12.09±2.97) and(19.86±3.40)ng/mL) were also higher than those in control group. After
calcitriol intervention, the
protein levels of α-SMA, TGF-β1 and
Vimentin(0.68±0.16, 0.85±0.21, 0.84±0.09) in liver tissue and the serum levels of HA, LN, PⅢNP and COL-Ⅳ((54.29±7.23), (55.56±9.43), (6.49±1.08), (10.15±1.99) ng/mL) were significantly lower than those of NaAsO_2-treated group(P<0.05).
CONCLUSION: