神经肽在去卵巢大鼠骨组织中表达差异的实验研究

目的探讨神经肽P物质(substance P,SP),降钙素基因相关肽(calcitonin gene-related peptide,CGRP),血管活性肠肽(vasoactive intestinal peptide,VIP)和神经肽Y(neuropeptide Y,NPY)在去卵巢组(ovariectomized,OVX)大鼠和假手术组(sham-operated,Sham)大鼠胫骨干骺端表达的差异以及与骨密度(bone mineral density,BMD)的相关性。方法 12只6月龄雌性未孕SD大鼠随机分为Sham组和OVX组,每组6只。造模后12 w两组大鼠称量体重后处死,取大鼠子宫称重,双能X线检测大鼠胫骨干骺端BMD,免疫组织化学法观察两组大鼠右侧胫骨干骺端SP,CGRP,VIP和NPY表达,取平均光密度(mean optical density,MOD)值,分析其与BMD之间相关性。结果造模后12 w,与Sham组相比较,OVX组大鼠体重增加,子宫湿重和BMD值降低,免疫组织化学法观察发现SP,CGRP和VIP的MOD值降低,NPY的MOD值升高,差异具有统计学意义(P0.01)。大鼠SP,VIP的MOD值与BMD值成正相关关系(r=0.746,P=0.005;r=0.591,P=0.043),NPY的MOD值与BMD值成负相关关系(r=-0.666,P=0.018)。结论骨质疏松可能与骨组织中神经肽的表达量改变有关,但其中具体机制有待进一步研究。

Experimental study on the difference of neuropeptide expression in bone tissue of ovariectomized rats

Objective To explore the expression of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) in tibia metaphysis bone tissue of ovariectomized (OVX) rats and sham-operation rats, and to investigate the relationship between neuropeptides and bone mineral density (BMD) of rats. Methods Twelve 6-month-old female SD rats which were not pregnant were randomly divided into two groups: Sham group (n=6) and OVX group (n=6). At 12 weeks post-operation, rats in both groups were weighed then executed, and their uteruses were excised and weighed. Dual-energy x-ray absorptiometry (DXA) was used to measure BMD of tibia metaphysis bone tissue. The expression of SP, CGRP, VIP and NPY in right tibia metaphysis bone tissue was detected by immunohistochemical analysis. The mean optical density (MOD) of neuropeptides was used to analyze the relationship between MOD and BMD. Results 12 weeks after operation, compared with sham group rats, OVX group rats had increased body weight, decreased BMD and wet weight of uterus, and a decrease in the MOD of SP, CGRP and VIP and an increase in the MOD of NPY were observed (P<0.01). Significant positive correlations were observed between the MOD of SP and VIP and BMD (r=0.746, P=0.005; r=0.591, P=0.043), and the MOD of NPY had a negative correlation with BMD (r= -0.666, P=0.018). Conclusion Osteoporosis may be related to the changes of neuropeptide expression in bone tissue, but the specific mechanism needs to be further studied.