Comparative study on the acute toxicity of pulmonary caused by nanosized and microsized powders of silicon dioxide / 中华预防医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To compare the acute pulmonary toxicities of nanosized and microsized silicon dioxide particles.</p><p><b>METHODS</b>All 125 healthy male Wistar rats were divided into 25 groups randomly according to the weight. Experimental animals were exposed to microsized SiO2 at the doses of 100 mg/m3 (group A) and 300 mg/m3 (group B), and to the nanosized SiO2 at the same dose levels (group A' and B') by inhalation for 2 hours. Compositions in bronchoalveolar lavage fluids (BALF) and contents of hydroxyproline in blood sera and lung tissues were detected and then compared at 6, 12, 24, 48, 72 hours after administration.</p><p><b>RESULTS</b>The total cellular score (TCS) in BALF of group A'[(55.00 +/- 8.30) x 10(4)/ ml] and B'[(52.50 +/- 9.02) x 10(4)/ml] at 6 hours were significantly higher than those in control groups [(34.88 +/- 12.53) x 10(4)/ml]; TCS in BALF of group A' [(55.00 +/- 8.30) x 10(4)/ml]at 6 hours and group A' [(39.75 +/- 12.08) x 10(4)/ml] at 24 hours were significantly higher than those in isodose group of microsized SiO2 [(32.38 +/- 13.07) x 10(4)/ml, (24.13 +/- 10.97) x 10(4)/ml) ]; total protein (TPr) in BALF of group A' [(0.34 +/- 0.09)g/L] and B' [(0.38 +/- 0.16) g/L] at 48 hours were significantly higher than those in isodose group of microsized SiO2 [(0.20 +/- 0.07) g/L, (0.21 +/- 0.05) g/L]. Lactate dehydrogenase (LDH) in BALF of group A' [(1.66 +/- 0.22) x 10(3) U/L] at 72 hours were significantly higher than those in isodose group of microsized SiO2 [(1.38 +/- 0.17) x 10(3) U/L]. Alkaline phosphatase (AKP) in BALF of group B' [(5.14 +/- 1.47) U/100 ml] at 6 hours and group B' [(5.86 +/- 2.41) U/100 ml] at 24 hours were significantly higher than those in isodose group of microsized SiO2 [(3.64 +/- 0.36) U/100 ml, (3.30 +/- 2.19) U/100 ml]. Hydroxyproline (HyP) in tissues of lung of group A' [(0.532 +/- 0.053) microg/mg, (0.484 +/- 0.046) microg/mg, (0.591 +/- 0.096) microg/mg, (0.551 +/- 0.084) microg/mg] at 6, 12, 48, 72 hours and group B' [(0.508 +/- 0.081) microg/mg, (0.565 +/- 0.053) microg/mg ] at 12, 72 hours were significantly higher than those in isodose group of microsized SiO2 [(0.345 +/- 0.074) microg/mg, (0.368 +/- 0.095) microg/mg, (0.431 +/- 0.036) microg/mg, (0.399 +/- 0.080) microg/mg, (0.396 +/- 0.039) microg/mg, (0.465 +/- 0.062) microg/mg].</p><p><b>CONCLUSION</b>Nanosized and microsized SiO2 should have some differences on acute pulmonary toxicities in our experiment condition.</p>