Metal pollution in Huayuan River in Hunan Province in China by manganese sulphate waste residue.

The Huayuan River in Hunan Province in China is subject to ongoing mining activity with Mn extraction. In this study, the level and environmental significance of metals (including Mn, Cd, Pb, Cu, Zn, Ni and Fe) concentrations in the surface water and river sediments have been investigated along a 187 km reach of the Huayuan River. Using the X-ray fluorescence (XRF) analysis, we analyzed the characterization of metals in manganese sulphate waste residue (MSWR) deposited along the bank of Huayuan River. The speciation of metals in both sediment and MSWR was established using the BCR-three step sequential extraction procedure. In the water samples, the average concentrations of Mn, Cd and Pb exceeded the acceptable concentrations for drinking water in the WHO Guidelines for drinking water quality, Vol. 1, Recommendations, Geneva (2004) and Chinese (GB 5749-2006) guidelines, respectively. The average concentrations of Mn, Cd, Pb and Zn in the river sediments were found to be considerably higher than the corresponding world average shale values. The percentages of Cd (31.4%), Mn (31.1%), Zn (12.8%) and Pb (8.1%) associated with exchangeable and weak acid fraction in the sediments were higher than other metals. Mn (5.81%), Zn (0.208%), Pb (0.0292%) and Cd (0.0113%) were identified in MSWR by XRF analysis. The percentages of Mn, Cd, Zn and Pb associated with the exchangeable and weak acid soluble fraction in MSWR were 41.9%, 31.1%, 23.8% and 9.8%, respectively. The peak solute and sediment-bound metal concentrations were found at the sites of MSWR deposited along the bank of Huayuan River. The results suggested that MSWR deposited along the bank may have a closely relation with the metal pollution of Huayuan River. The results obtained may be useful to assess both short and long-term environmental impact of the MSWR deposited activities and support decisions for a future remediation of this river.

[Effects of sinomenine on NO/nNOS system in cerebellum and spinal cord of morphine-dependent and withdrawal mice].

To explore the effect of sinomenine on the nitric oxide (NO)/neural nitric oxide synthase (nNOS) system in the cerebellum and spinal cord of morphine-dependent and morphine-withdrawal Kunming mice, mice were subjected to injection of morphine with an increasing dose for 5 d, and then were treated with sinomenine (40 mg/kg, i.p.) for another 5 d. Naloxone was used to develop acute withdrawal, and the withdrawal syndromes, including teeth chattering, twisting, straightening, sneezing and ptosis, were investigated. nNOS mRNA expressions in the cerebellum and spinal cord were determined by semi-quantitative RT-PCR. nNOS activity and NO level were determined by the chemistry-colorimetry and nitrate reductase-reduction, respectively. The results obtained were as follows: (1) Sinomenine restored the decrease in body weight and alleviated the signs of morphine-withdrawal in mice. (2) Sinomenine also reduced the increases in nNOS mRNA expression and nNOS activity resulting from morphine-dependence, and simultaneously attenuated the high level of NO in both tissues following morphine-withdrawal. (3) Administration of sinomenine alone did not develop physical dependence in mice. The results obtained indicate that sinomenine may attenuate morphine addiction and significantly alleviate morphine-withdrawal symptoms, and the mechanism may be associated with the effect of sinomenine on the NO/nNOS system in the cerebellum and spinal cord.