摘要
本文利用非侵入计算层析X射线摄影法(pQCT)研究了雄性波罗的海友海豹(4～23岁龄)骨组织的矿物密度(mg/cm^3)。资料按照收集的年份分组。A组:1850～1955年,有机氯(OCs)大量引入之前的时期;B组:1965～1985年,OC污染十分严重的时期;C组:1986～1997年,OCs浓度逐渐减小的时期。测量结果的复现性良好,变异系数(CV)为0.1%～2.1%。1986～1997年收集的标本中桡骨小梁的矿物密度比1965～1985年收集的标本的明显要高(p<0.05)。1986～1997年收集的标本中,下颌骨的皮层骨矿物密度明显地低于1850～1955年收集的标本(p<0.05)。这些结果表明小梁和皮层骨在一段时间内的不同响应。在OC污染非常严重的时期(1965～1985年),小梁骨矿物密度最低,而在1985～1997年收集的标本中,皮层骨密度最低,该时段是一个OC污染程度相当低的时期。有关这些效应背后的机制目前尚不知道。但是,可以假定这里涉及到OCs。由于目前缺乏有关研究个体中OCs残留水平的资料,因此不可能评估OCs在这方面的影响。
Bone mineral density (mg cm^-3) was studied in male Baltic grey seals (4–23 years of age) by noninvasive computed tomography (pQCT). The material was grouped according to year of collection. Group A: 1850–1955, a period before the main introduction of organochlorines (OCs); Group B: 1965–1985, a period with very high OC contamination; and Group C: 1986–1997, a period with decreasing concentrations of OCs. The reproducibility of the measurements was good with a Coefficient of Variation (CV) ranging from 0.1% to 2.1%. Trabecular bone mineral density of the radius was significantly higher in specimens collected 1986–1997 than in those collected 1965–1985 (p < 0.05). Cortical bone mineral density of the mandible was significantly lower in specimens collected 1986–1997 compared with those collected 1850–1955 (p < 0.05). These results indicate different responses over time in trabecular and cortical bone. During the period of very high OC contamination (1965–1985), trabecular bone density was lowest, whereas cortical bone density was lowest in specimens collected 1985–1997, representing a period of fairly low OC contamination. The mechanisms behind these effects are not known. However, it can be assumed that OCs are involved. Information about residue levels of OCs in the studied individuals is lacking and, therefore, it was not possible to evaluate the impact of OCs in this respect.
