Effects of lactational dioxin exposure to development of alveolar bone in SD rat offspring / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the influence of lactational dioxin exposure (2, 3, 7, 8-tetrachlorodibenzo-p-dixon, TCDD) on development of alveolar bone in SD rat offspring.</p><p><b>METHODS</b>The rats of TCDD exposure group and control group were sacrificed and the alveolar bone with molars of PD60 rats in the two groups were embedded in resin. The sections were observed by fluorescent microscope. The alveolar bone formation was evaluated by histological examination, tetracycline fluorescence marker and quantitative histomorphometry. The indices of quantitative histomorphometry were compared.</p><p><b>RESULTS</b>The trabecular structure of alveolar bone was looser in TCDD exposure group than in the control group. The tetracycline fluorescence markers were more disorganized in TCDD group. The indices of quantitative histomorphometry of alveolar bone between two groups showed significantly different.</p><p><b>CONCLUSIONS</b>Lactational 2,3,7,8-TCDD exposure decreased the quality and quantity of alveolar bone in SD rat offspring. It is suggested that dioxins exposure may interrupt the spatial configuration.</p>

The effect of lead exposure in utero on the teeth eruption and enamel development of rat offspring / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of lead exposure at different levels in utero on the teeth eruption and enamel development of rat offsprings.</p><p><b>METHODS</b>27 pregnant SD rats were divided into three groups randomly: high level lead group (HLG), low level lead group (LLG) and control group with nine rats in each group. The three groups from the gestation day to the end of the gestation were given either deionized water in control group or deionized water containing 200 mg/L Pb2+ as lead acetate through drinking method in high level lead experimental group and 50 mg/L Pb2+ as lead acetate through drinking method in low level lead experimental group. The incisors of newborn rats were marked at the level of the gingival papilla on the 26th day after birth. On the 36th day, the incisors of newborn rats were marked again at the same level. Then the rat offsprings were killed and their blood was collected for lead analysis. The mandible incisors of rat offspring were separated and the content of Pb in incisors was determined by using a graphite furnace atomic absorption spectrometric method. The teeth of rat offspring were observed and the distance between two marks were measured by means of stereomicroscope. The ratio of calcium to phosphate of enamel of rat offspring was compared by electron probe microanalyses.</p><p><b>RESULTS</b>The level of blood lead in 200 mg/L, 50 mg/L treated rat offspring groups was higher than that in control group. The tooth lead of 200 mg/L, 50 mg/L treated rat offspring groups [(77.3 +/- 6.3), (27.8 +/- 4.5) microg/g] were higher than the control [(6.6 +/- 0.8) microg/g, P < 0.01]. Compared with the control group, the teeth of lead exposure experimental groups were smaller and severity of attrition was obvious and pulpal perforations were often observed. These appearances was more distinct in rats of high level lead experimental group. The incisors of lead-treated rat offspring erupted [(0.25 +/- 0.08), (0.30 +/- 0.09) mm/d] more slowly than control ones [(0.39 +/- 0.09) mm/d, P < 0.01]. The ratio of calcium to phosphate (Ca/P) decreased with the increase of lead exposure. It was found that Ca/P in lead exposure experimental groups (1.68 +/- 0.54), (1.37 +/- 0.47) was significantly lower than that in the control group (2.14 +/- 0.33).</p><p><b>CONCLUSION</b>Lead exposure in utero affects the normal eruption of teeth and enamel formation and the degree was related with the lead exposure level.</p>

The effects of a diterpenoid compound 5F isolated from pteris semipinnata L on the activity and expression of mitogen activated protein kinase in K562 cells / 中国药理学通报

AIM: To study the effects of a diterpenoid compound 5F (ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid) isolated from pteris semipinnata L on the the activity and expression of mitogen activated protein kinase of K562 cells. METHODS: K562 cells were treated with compound 5F for 24 hours, then MAPK activity was determined using MBP as substrate, Western blotting was used to detect the effect of compound 5F on the expression of MAPK. RESULTS: The activity and expression of MAPK increased after the treatment of 5F. CONCLUSION: One mechanism of the anti-tumor effect of compound 5F is through abnormal activation and abnormal expression of MAPK.