| Objective:1. Observe the distribution of lead content of the New Zealand rabbits blood, bone, synovium and articular cartilage when water poisoning.2. Observe the effect of chronic lead poisoning of drinking water in New Zealand rabbit knee cartilage morphology and composition of articular cartilage gene expression.Methods: 40 rabbits were randomly divided into experimental group and control group(n =20). Feeding experimental group was given with lead acetate (1g/L) drinking water, animals were observed mental state and body weight changes. Raising three months. 14 rats in each group were randomly selected animals, heart blood, determine blood lead levels; take 1cm on his right knee at the femur bone in the determination of lead content; take knees synovium, synovial determination of lead content; take double knee cartilage, articular cartilage in the determination of lead content. 3 animals in each group were randomly selected, cut a full bilateral knee cartilage and synovial general observation form, parallel embedded sections of tissue decalcification, line cartilage HE, Safranin O and toluidine blue staining, light microscopy, the line Mankin cartilage scores histological criteria, HE stain line parallel pathological synovial inflammation grade. Each of three randomly selected animals were weight-bearing area of femoral condyle articular cartilage, electron microscopy of cartilage cells and their mitochondria, rough endoplasmic reticulum and other organelles and extracellular matrix in the form of collagen fibers in the course and distribution, to take over the articular cartilage real time quantitative RT-PCR assay for quantification of cartilage type II collagen and glycosaminoglycan mRNA expression.Results:1. The control group gained weight upward trend; the experimental group than in the control group animals, the slow weight gain, That growth curve was rather flat, exposed to lead from the 4th week weight behind the control group (P<0.05), and always maintained in a relatively low level (P<0.05).2. Compared with the control group, blood, bone, synovial membrane and articular cartilage of the lead content of experimental group increased significantly (P<0.01). Experimental group has the highest lead content of bone, followed by the synovial membrane, and the third for the articular cartilage, blood in the least. Articular cartilage and blood lead levels, bone and synovium of the lead content was positively related and appeared linear (P<0.01). 3. Experimental articular cartilage, synovial membrane and other general observations were no significant difference compared with the control group, the articular cartilage surface is smooth, shiny; no congestion and swelling were seen in synovial; synovial fluid was observed viscous and little. HE staining observed by light microscopy suggested the articular cartilage of experimental group was thin, the cartilage cells in the deep was disorder, cartilage cells decreased and showed cluster of chondrocytes; Also Safranin O and toluidine blue staining, confirmed the deep cartilage matrix stained lighter than normal . Mankin cartilage scores and synovitis Disease Rating provided experimental group was higher than in the control group (P<0.05). Transmission electron microscopy further confirmed the chondrocytes of experimental group were irregular in shape and the membrane boundary is still clear that there is no discontinuity, cytoplasmic mitochondria, organelles such as endoplasmic reticulum decreased, swelling and disintegration, showing large vacuoles, nuclear deformation, electron density increased. Experimental group has sparser collagen fibers than the control group, no obvious grid-like arrangement was observed.4. The experimental group of rabbit articular cartilage in typeâ…¡collagen mRNA expression was significantly decreased compared with the control group (P<0.05), glycosaminoglycan in cartilage mRNA expression was significantly decreased compared with the control group (P <0.05).Conclusion:1. Chronic lead poisoning drinking water of lead in blood, bone, synovial membrane and articular cartilage in both the distribution of the highest lead content of bone, followed by synovial membrane, articular cartilage and blood. And blood lead levels of articular cartilage was positively related with bone and synovial membrane.2. Lead by inhibiting the gene expression of cartilage components, induced the normal structure of cartilage and change of biological indicators and cartilage cell dysfunction, affecting the synthesis and degradation of articular cartilage type II collagen then glycosaminoglycan. Articular cartilage is injured by lead. |
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