Low expression of vascular endothelial growth factor and high serum level of cyclic guanine monophosphate as the risk factors of femoral head osteonecrosis in alcohol-exposed Wistar rat

Abstract

Purpose: Severe damage to the femoral head in patients with osteonecrosis has a high impact on morbidity. Despite early diagnosis, the treatment outcome is still unsatisfactory. This study aimed to explore the expression of vascular endothelial growth factor (VEGF) and cyclic guanine monophosphate (cGMP) serum level as the risk factors of femoral head osteonecrosis in alcohol-exposed Wistar rats.

Methods: This was an experimental study using randomized post-test only control group design, with samples using 10-14 weeks Wistar male rats. Rats were then divided into 6 groups: 3 groups without intervention, and 3 groups with intervention using 40% alcohol given perorally. Each one group from intervention and control group was euthanized by the end of the week for 3 consecutive weeks. Proximal femurs were examined under microscope for osteonecrosis, immunohistochemically for VEGF, and blood serum for cGMP levels.

Results: VEGF expression in the femoral head of alcohol-exposed Wistar rats was lower than those not exposed to alcohol (p < 0.005). Blood serum cGMP levels of alcohol-exposed Wistar rats were higher than those not exposed to alcohol (p < 0.005). The number of necrotic osteocytes in the femoral head of Wistar rats exposed to alcohol was greater than those not exposed to alcohol (p < 0.005). There are significant differences between VEGF, cGMP levels, and number of necrotic osteocytes in the control group and treatment at 1st, 2nd^, and 3rd week (p < 0.005).

Conclusions: Based on the result of this study, VEGF and cGMP may be considered as diagnostic biomarkers for alcohol-induced femoral head osteonecrosis.

Keywords: Cyclic guanosine monophosphate; Osteonecrosis; Vascular endothelial growth factor.

Fig. 1

Flow diagram of study.

Fig. 2

Vascular endothelial growth factor: (A) 1st week control group, (B) 2nd weeks control group, (C) 3rd weeks control group, (D) 1st week alcohol group, (E) 2nd weeks alcohol group, (F) 3rd weeks alcohol group. Green arrows shows positive of VEGF staining (A, B and C) and red arrows shows negative or minimal VEGF staining (D, E and F).

Fig. 3

Osteocytes necrosis: (A) 1st week control group, (B) 2nd weeks control group, (C) 3rd weeks control group, (D) 1st week alcohol group, (E) 2nd weeks alcohol group, (F) 3rd weeks alcohol group. The alcohol group rats show the formation of appositional bone around necrotic bone trabeculae, which represents part of the repair process, at 1, 2 and 3 weeks (red arrow).