动物造模 z-bio 2021-09-15 281

　　OBJECTIVE: To apply the OPG-RANK-RANKL ligand (OPG-RANK-RANKL) system to discuss the effects of different levels of dietary calcium on bone metabolism in growing WHBE rabbits.

　　Method: 21 male weaned WHBE rabbits were selected and randomly divided into 3 groups (group I, II, and III), and were fed with calcium levels of 0.95%, 1.10% and 1.30%, and other diets with fundamentally different nutritional levels. The experimental period was 42 days. After the experiment was completed, the rabbit serum calcium (Ca), parathyroid hormone (PTH) and bone-derived alkaline enzyme (BALP) content were determined; fluorescent quantitative PCR and immunohistochemical methods were used to stop OPG-RANK on WHBE rabbit bone tissues. -Analysis of gene transcription and protein expression of RANKL. Finally, the RANKL/OPG ratio was used as an index to evaluate the correlation between WHBE rabbit bone metabolism and the level of dietary calcium.

　　Results: The experimental results indicated that there was no significant difference in serum Ca, PTH content and BALP vitality in groups I, II, and III (P>0.05). The expression level of RANKL mRNA and the ratio of RANKL/OPG mRNA in WHBE rabbit bone tissue were the lowest in group Ⅱ, which was significantly different from groups I and Ⅲ (P<0.05). The degree of calcium has a significant effect on the expression of OPG-RANK-RANKL protein in WHBE rabbit bone tissue (P<0.01). The positive indexes of OPG protein expression in groups Ⅱ and Ⅲ were significantly higher than those in group I (P<0.01); while in group Ⅱ rabbit bone The positive index of tissue RANK protein expression was significantly lower than that of group I and group III (P<0.01). The ratio of positive index of RANKL/OPG protein expression was the lowest in group II, which was significantly different from group I (P<0.01). In addition, WHBE rabbit bone tissue RANKL/OPG mRNA ratio and protein expression positive index ratio had a significant quadratic curve correlation with the level of dietary calcium (R2=0.4068, 0.8433, P<0.05, P<0.001).

　　Conclusion: There is a significant correlation between the bone metabolism of WHBE rabbits in the growing period and the calcium level of the diet. When the calcium content of the diet is 1.10%, the WHBE rabbits in the growing period can achieve a more ideal bone metabolism.