[Impact of subchronic exposure to low-dose nano-nickel oxide on the reproductive function and offspring of male rats].

OBJECTIVE: To investigate the influence of subchronic exposure to low-dose subchronic nano-nickel oxide (NNO) on the reproductive function of male rats and embryonic development of the pregnant rats. METHODS: Fifty normal healthy male SD rats weighing 180－220 g were randomly divided into five groups of equal number, negative control, 4 mg/ml micro-nickel oxide (MNO), and 0.16, 0.8 and 4 mg/ml NNO, those of the latter four groups exposed to MNO or NNO by non-contact intratracheal instillation once every 3 days for 60 days, and then all mated with normal adult female rats in the ratio of 1∶2. After the female animals were confirmed to be pregnant, the males were sacrificed and the weights of the body, testis and epididymis obtained, followed by calculation of the visceral coefficients, determination of epididymal sperm concentration and viability and the nickel contents in the blood and semen by atomic fluorescence spectrometry. The female rats were killed on the 20th day of gestation for counting of the implanted fertilized eggs and live, dead and resorbed fetuses. RESULTS: After 60 days of exposure, the rats of the NNO groups showed no statistically significant differences from those of the negative control and MNO groups in the weights of the body, testis and epididymis or visceral coefficients. Compared with the negative control group, the animals of the 0.8 and 4 mg/ml NNO groups exhibited markedly decreased sperm concentration (ï¼»9.36 ± 0.98ï¼½ vs ï¼»7.49 ± 1.46ï¼½ and ï¼»6.30 ± 1.36ï¼½ ×106/ml, P < 0.05) and viable sperm (ï¼»85.35 ± 9.16ï¼½% vs ï¼»68.26 ± 16.63ï¼½% and ï¼»65.88 ± 14.68ï¼½ %, P < 0.05), increased morphologically abnormal sperm (ï¼»8.30 ± 2.47ï¼½% vs ï¼»13.99 ± 4.87ï¼½% and ï¼»15.38 ± 8.86ï¼½ %, P < 0.05), and elevated rate of dead and resorbed fetuses (1.18% vs 6.89% and 7.37%, P < 0.05), blood nickel content (ï¼»0.13 ± 0.16ï¼½ vs ï¼»0.52 ± 0.34ï¼½ and ï¼»0.82 ± 0.44ï¼½ mg/L, P < 0.05) and semen nickel content (ï¼»0.08 ± 0.13ï¼½ vs ï¼»0.35 ± 0.23ï¼½ and ï¼»0.63 ± 0.61ï¼½ mg/L, P < 0.05). The nickel level in the semen was correlated significantly with that in the blood (r = 0.912, P <0.01), negatively with the rate of viable sperm (r = －0.879, P <0.01) and positively with the percentage of morphologically abnormal sperm (r = －0.898, P <0.01). CONCLUSIONS: Sixty-day exposure to nano-nickel oxide at 0.8 and 4 mg/ml can produce reproductive toxicity in male rats and result in fetal abnormality in the females, while that at 0.16 mg/ml has no significant toxic effect on the reproductive function of the males.

Ligustrazine monomer against cerebral ischemia/reperfusion injury.

Ligustrazine (2,3,5,6-tetramethylpyrazine) is a major active ingredient of the Szechwan lovage rhizome and is extensively used in treatment of ischemic cerebrovascular disease. The mechanism of action of ligustrazine use against ischemic cerebrovascular diseases remains unclear at present. This study summarizes its protective effect, the optimum time window of administration, and the most effective mode of administration for clinical treatment of cerebral ischemia/reperfusion injury. We examine the effects of ligustrazine on suppressing excitatory amino acid release, promoting migration, differentiation and proliferation of endogenous neural stem cells. We also looked at its effects on angiogenesis and how it inhibits thrombosis, the inflammatory response, and apoptosis after cerebral ischemia. We consider that ligustrazine gives noticeable protection from cerebral ischemia/reperfusion injury. The time window of ligustrazine administration is limited. The protective effect and time window of a series of derivative monomers of ligustrazine such as 2-[(1,1-dimethylethyl)oxidoimino]methyl]-3,5,6-trimethylpyrazine, CXC137 and CXC195 after cerebral ischemia were better than ligustrazine.

Design and synthesis of novel galactosylated polymers for liposomes as gene drug carriers targeting the hepatic asialoglycoprotein receptor.

The 18-mer oligodeoxynucleotides (ODNs) that can inhibit survivin gene expression were selected as a model gene drug to study hepatic-targeting drug delivery system. Novel galactosylated polymers (cholesteryloxycarbonylamino) ethylamine-alpha,beta-polyasparthydrazied (CHE-PAHy-Lacs), which target asialoglycoprotein receptor on hepatic parenchymal cells (PC), were designed and synthesized as non-toxic, non-antigenic and non-teratogenic ligands for liposomes. The liposomes incorporating different CHE-PAHy-Lacs were prepared and characterized by zeta potential and particle size analyzer. The drug encapsulation efficiency was measured by gel filtration method. 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate was used as a marker for all the liposome preparations in the in vivo experiments. The CHE-PAHy-Lac liposomes produced a significant improvement in the encapsulation efficiency of ODNs (28.73-51.37%) compared with conventional liposomes (9.88%). The in vivo results showed that the liposomes incorporating CHE-PAHy-Lac, which contained about 30% (w/w) galactosyl residues, exhibited marked accumulation in the liver and hepatic PC. These results suggest that the novel galactosylated polymers used for liposomes have a great potential as a gene delivery system for hepatic targeting.