Evaluation of the toxicity of fluorine in Antarctic krill on soft tissues of Wistar rats

Antarctic krill are a potential food source for humans and animals, but krill are known to contain high levels of fluorine （F）. In this study, we investigated the toxicity of F in Antarctic krill using Wistar rats. There were three experimental groups： The control group were fed a basal diet, the krill treatment group were fed the same basal diet mixed with krill powder （150 mg＇kg-~ F）, and the sodium fluoride （NaF） treatment group were fed the basal diet with added NaF （150 mg.kg1 F）. General toxicity indicators including body weight and food intake were measured during the experiment. After three months the rats were dissected and tissue samples were collected from the liver, kidney, spleen, brain, and testis. Morphological changes in the cells of these tissues were assessed using HE staining. There were no significant differences in the body weight, the food intake, or the viscera coefficients among the three groups. In both treatment groups some pathological changes were observed in all soft tissue samples except the testis, although there were fewer and less severe pathological changes in the krill treatment group than in the NaF treatment group. The results showed that the toxicity of F in Antarctic krill was lower than for an equivalent amount of F in NaF, but it was still toxic to rats consuming large quantities of krill. The findings of this study highlight the need for further investigation into potential F toxicity if krill is to be used for human consumption.

Histological Characteristics of Hair Follicle Structure of Hezuo Swine from Gansu Province

The characteristics of skin hair follicle structure of Hezuo swine were in- vestigated using frozen section method and HE staining. Experimental results showed that the hair root, hair tip, outer sheath, inner sheath, hair follicle group, fi- brous sheath, outer epidermis, inner epidermis, sebaceous gland and other organiza- tional structures of hair follicles of Hezuo swine can be clearly observed. The hair follicle pore size varied extremely significantly （P〈0.01） among different parts, showing a downward trend of shoulder 〈 body side 〈 buttocks; the hair follicle density ranged from 5.59 to 7.26 hair follicles/mm^2. This study provides reference for the in-dustrial and medical applications.

Morphology of Rat Testis Preserved in Three Different Fixatives

Histopathological examination of testes is important in assessing spermatogenesis and testicular function. Modified Davidson＇s fluid （mDF） has been proposed as a superior substitute for Bouin＇s fluid （BF） for fixation of adult animal testes. Besides, 4% paraformaldehyde （PFA） has been commonly used to fix testes with convenience. We compared the morphology of the rat testis fixed in 4% PFA, mDF, or BF using hematoxylin and eosin （HE）-stained sections. Fixation in 4% PFA resulted in obvious tissue shrinkage artifacts, especially between seminiferous epithelium cells. Shrinkage artifacts were also observed in the central area of the testes fixed in BF. Use of mDF did not cause shrinkage artifacts between seminiferous tubules, though a small amount can be observed in seminiferous tubules between germ cells. Clarity of nuclear detail in testes fixed in mDF and BF is better compared to 4% PFA. Our study demonstrated that fixation in mDF provided better morphologic details in the rat testis as compared with 4% PFA and BF.

Effects of Agaricus blazei Murill Polysaccharides on Leadinduced Disturbance of Morphology and ASIC1a and ASIC2b Gene Expression in Hippocampus of Rats

The present study was undertaken to investigate the effects of Agaricus blazei murill polysaccharides on morphology of hippocampus tissue and expression of ASIC1a and ASIC2b mRNA in lead-poisoning rats.Forty SD rats were divided into five groups：control group,lead group,experimental group 1,2,3.After 60d of treatments,hippocampus tissues were observed by HE staining and the expression levels of ASIC1a and ASIC2b mRNA were determined by the flouoreescent quantitative real-time polymerase chain reaction（FQRT-PCR）.The results showed that after lead induction,the number of hippocampus neuron increased,cell gap increased,the chromatin was stained lightly;after administration of ABMP,the number of the hippocampus neuron increased as the dose of ABMP rose,cell gap decreased,the chromatin was stained darkly.The expression level of ASIC1a mRNA in hippocampus of rats in ABMP group decreased extremely significantly compared with that in the model group（P〈0.01）.Lead exposure and ABMP exhibited no significant effects on the expression level of ASIC2b mRNA.ABMP possesses a protective effect on nervous system of rats exposed to lead by combining with lead.

The protective effect of ginsenoside Rb1 pre-treatment on myocardial ischemia/reperfusion injury in Sprague-Dawley rats

Background Myocardial ischemia/reperfusion injury(MI/RI)during myocardial infarction worsens outcomes. It has been proved that ginsenoside Rb1 has a great impact on ischemia/reperfusion(I/R)injury. The aim of this study is to explore the protective effect of the pretreatment with ginsenoside Rb1 on MI/RI and investigate the underlying mechanisms about the preventive action. Methods A total of 27 healthy adult Sprague-Dawley(SD)rats were randomly divided into 3 groups(n=9 per group):A sham-operated group(Sham n=9);an ischemia 40 min/reperfusion 2 h(I/R n=9)of the cardiac muscle group;Rb1-treated group was divided into 3 subgroups(Rb1 10 mg/kg,20 mg/kg,40 mg/kg,n=3). Ginsenosides Rb1 at different concentrations were injected intraperitoneally for 3 days continuously before ligation. A model of MI/RI was constructed by ligation of the left coronary artery anterior descending branch in rats. Myocardial infarction area after I/R was measured bytriphenyltetrazolium chloride(TTC)staining of myocardial tissue. Hematoxylin and eosin(HE)staining and electrocardiogram indication were used to observe myocardial cell injury and ischemia,respectively. The expression of caspase-8 protein was observed by immunohistochemistry staining. Results The pretreatment of 40 mg/kg dose of ginsenoside Rb1 could decrease the expression of caspase-8 protein caused by I/R and the apoptosis of myocardial cells,improve myocardial ischemia,reduce the area of myocardial infarction and ameliorate MI/RI.Conclusions These results demonstrate that ginsenoside Rb1 has a significant protective effect on MI/RI through attenuating the apoptosis of myocardial cells and improving myocardial ischemia at appropriate dose,which provides new insights into the potential therapy of MI/RI.