Expression of Cx43 and Cx45 in Cardiomyocytes of an Overworked Rat Model

Abstract

Objective To study the effect of overwork stress response on the expression of connexin 43（Cx43） and connexin 45（Cx45） in cardiomyocytes and on cardiac function. Methods The experimental animals were divided into control group, overworked 1-month group and overworked 2-month group. A overworked rat model was established by forcing swimming of overworked group. The expressions of Cx43 and Cx45 in myocardial tissues of experimental animals were detected by Western blotting, while the corresponding myocardial tissues were stained with hematoxylin-eosin （HE） staining and Masson's staining, then histologically observed. Results Western blotting results showed that, compared with the control group, Cx43 expression in myocardial tissues of overworked rats decreased while Cx45 expression increased. HE staining and Masson's staining results showed that hypertrophy, rupture and interstitial fiber tissue hyperplasia were observed in myocardial fibers of overworked rats. Conclusion Overwork stress response may affect cardiac function as an independent factor and may even cause heart failure or arrhythmias and lead to death.

The Concept, Status Quo and Forensic Pathology of Karoshi

Abstract

"Karoshi" originates from Japan's economic take-off period in the 1960s and 1970s. It is generally believed that overwork lead to the accumulation of fatigue, which triggers the outbreak of potential diseases, and results in sudden death. Karoshi causes great harm to both the community and families because it occurs primarily in 30 to 60 year old young adults. Japan put Karoshi into the category of industrial injury for the first time in 2001 and started to undertake a series of studies in the sociological and pathological fields. However, there is a tremendous gap in the forensic pathological diagnosis domain. In China, research on Karoshi started from the 1990s and is closely related to the reform and opening up policy as well as economic development. According to the incomplete statistics, 600 thousand people die from overwork each year in China, the highest in the world. Karoshi has become one of the most serious social problems in China at the present stage, thus a systematic study in the sociology and forensic pathology fields is urgently required. This paper summarizes the past and present status of Karoshi, and puts forward the problems that need attention during the judicial expertise of Karoshi from forensic pathology perspective.

A review of cinnabar (HgS) and/or realgar (As4S4)-containing traditional medicines

ETHNOPHARMOCOLOGICAL RELEVANCE

Herbo-metallic preparations have a long history in the treatment of diseases, and are still used today for refractory diseases, as adjuncts to standard therapy, or for economic reasons in developing countries.

AIM OF THE REVIEW

This review uses cinnabar (HgS) and realgar (As₄S₄) as mineral examples to discuss their occurrence, therapeutic use, pharmacology, toxicity in traditional medicine mixtures, and research perspectives.

MATERIALS AND METHODS

A literature search on cinnabar and realgar from PubMed, Chinese pharmacopeia, Google and other sources was carried out. Traditional medicines containing both cinnabar and realgar (An-Gong-Niu-Huang Wan, Hua-Feng-Dan); mainly cinnabar (Zhu-Sha-An-Shen Wan; Zuotai and Dangzuo), and mainly realgar (Huang-Dai Pian; Liu-Shen Wan; Niu-Huang-Jie-Du) are discussed.

RESULTS

Both cinnabar and realgar used in traditional medicines are subjected to special preparation procedures to remove impurities. Metals in these traditional medicines are in the sulfide forms which are different from environmental mercurials (HgCl₂, MeHg) or arsenicals (NaAsO₂, NaH₂AsO₄). Cinnabar and/or realgar are seldom used alone, but rather as mixtures with herbs and/or animal products in traditional medicines. Advanced technologies are now used to characterize these preparations. The bioaccessibility, absorption, distribution, metabolism and elimination of these herbo-metallic preparations are different from environmental metals. The rationale of including metals in traditional remedies and their interactions with drugs need to be justified. At higher therapeutic doses, balance of the benefits and risks is critical. Surveillance of patients using these herbo-metallic preparations is desired.

CONCLUSION

Chemical forms of mercury and arsenic are a major determinant of their disposition, efficacy and toxicity, and the use of total Hg and As alone for risk assessment of metals in traditional medicines is insufficient.

Zuotai and HgS differ from HgCl2 and methyl mercury in Hg accumulation and toxicity in weanling and aged rats

Mercury sulfides are used in Ayurvedic medicines, Tibetan medicines, and Chinese medicines for thousands of years and are still used today. Cinnabar (α-HgS) and metacinnabar (β-HgS) are different from mercury chloride (HgCl₂) and methylmercury (MeHg) in their disposition and toxicity. Whether such scenario applies to weanling and aged animals is not known. To address this question, weanling (21d) and aged (450d) rats were orally given Zuotai (54% β-HgS, 30mg/kg), HgS (α-HgS, 30mg/kg), HgCl₂ (34.6mg/kg), or MeHg (MeHgCl, 3.2mg/kg) for 7days. Accumulation of Hg in kidney and liver, and the toxicity-sensitive gene expressions were examined. Animal body weight gain was decreased by HgCl₂ and to a lesser extent by MeHg, but unaltered after Zuotai and HgS. HgCl₂ and MeHg produced dramatic tissue Hg accumulation, increased kidney (kim-1 and Ngal) and liver (Ho-1) injury-sensitive gene expressions, but such changes are absent or mild after Zuotai and HgS. Aged rats were more susceptible than weanling rats to Hg toxicity. To examine roles of transporters in Hg accumulation, transporter gene expressions were examined. The expression of renal uptake transporters Oat1, Oct2, and Oatp4c1 and hepatic Oatp2 was decreased, while the expression of renal efflux transporter Mrp2, Mrp4 and Mdr1b was increased following HgCl₂ and MeHg, but unaffected by Zuotai and HgS. Thus, Zuotai and HgS differ from HgCl₂ and MeHg in producing tissue Hg accumulation and toxicity, and aged rats are more susceptible than weanling rats. Transporter expression could be adaptive means to reduce tissue Hg burden.

[Distinct effect of Wansheng Huafeng Dan containing ardisia crenata on renal transporters, mercury accumulation and Kim-1 expression from mercuric chloride]

To study the effect of Wansheng Huafeng Dan (WSHFD) and mercuric chloride on renal mercury (Hg) extraction transporters (Oat1, Oct2), renal mercury excretion transporters (Mrp4, Mate2K), renal mercury accumulation and kidney injury molecule-1 (Kim-1). The ancient prescription of WSHFD containing 10-fold Hg caused much lower renal mercury accumulation and renal toxicity than HgCl2 in rats, with less effect on renal transporters than HgCl2. The above indicators had no significant difference in WSHFDO, WSHFD2 and WSHFD3 groups, indicating no effect of WSHFD with reduced or no cinnabar.

OX40 Ligand Levels and High-Sensitivity C-Reactive Protein Levels in Blood from Local Coronary Plaque and the Femoral Artery in Patients with Acute Coronary Syndrome or Stable Angina

OX40 ligand (OX40L) and high-sensitivity C-reactive protein (hs-CRP) play important roles in the pathogenesis of atherosclerosis. In this study, consecutive patients with acute coronary syndrome (ACS; n = 90) or stable angina (SA; n = 40) and healthy control subjects ( n = 50) were evaluated to assess plasma OX40L and serum hs-CRP levels in local coronary plaque and the femoral artery. OX40L and hs-CRP levels in the femoral artery were significantly higher in patients with ACS compared with controls. OX40L and hs-CRP levels in local coronary plaque (OX40Lc and hs-CRPc, respectively) were significantly higher in ACS than in SA patients. OX40L and hs-CRP levels were positively correlated with each other and were also correlated with fibrinogen levels. The number of complex lesions was correlated with OX40Lc and hs-CRPc levels. It is concluded that the OX40Lc level was highly sensitive for evaluating the inflammatory response in ACS and elevated levels of OX40Lc may be a valuable predictive marker for increased risk of atherosclerotic progression in ACS patients.

Chemical form of metals in traditional medicines underlines potential toxicity in cell cultures

ETHNOPHARMACOLOGICAL RELEVANCE

Mercury (Hg) and arsenic (As) are frequently found in traditional medicines as sulfides, such as cinnabar (HgS) and realgar (As(4)S(4)). There is a general perception that any medicinal use of such metal-containing remedies is unacceptable. An opposing opinion is that different chemical forms of arsenic and mercury have different toxic potentials.

AIM OF THE STUDY

To clarify this question, cinnabar, realgar, and cinnabar- and realgar-containing traditional medicine An-Gong-Niu-HuangWan (AGNH), were compared to well-known mercurials (HgS, HgCl(2) and MeHg) and arsenicals (As(2)S(2), As(2)O(3), NaAsO(2), and Na(2)HAsO(4)) for their cytotoxicity in human and rodent cell lines.

MATERIALS AND METHOD

Cultured cells derived from target organs such as brain (HAPI) and liver (Hep3B, HepG2 and TRL1215) were treated with chemicals for 48 h and cytotoxicity was determined by the MTS assay.

RESULTS

MeHg was most toxic with LC(50) of 4-20μM, followed by NaAsO(2) (LC(50), 25-250 μM) and HgCl(2) (LC(50,) 50-100 μM), Na(2)HAsO(4)(LC(50), 60-400μM), As(2)O(3)(LC(50), 30-900 μM), and As(2)S(2) (LC(50), 100-500 μM). In comparison, the LC(50) of realgar ranged from 250 to1500 μM; whereas cinnabar or HgS were approximately 20,000 μM and the toxicity of AGNH was in the range of 1500-8000 μM. Approximately 5000-fold differences exist between MeHg and HgS, and over 10-fold differences exist between NaAsO(2) and As(4)S(4).

CONCLUSIONS

Chemical forms of metals are important factor in determining their toxicity in traditional medicines, both cinnabar and realgar are much less toxic than well-known mercurial and arsenicals.

Realgar, cinnabar and An-Gong-Niu-Huang Wan are much less chronically nephrotoxic than common arsenicals and mercurials

Realgar (As(4)S(4)) and cinnabar (HgS) are frequently included in traditional Chinese medicines and Indian Ayurvedic medicines. Both As and Hg are well known for toxic effects, and their safety is of concern. The aim of this study was to compare chronic nephrotoxicity of An-Gong-Niu-Huang Wan (AGNH), realgar and cinnabar with common arsenicals and mercurials. Mice were orally administrated with AGNH (3 g/kg, 6-fold of clinical dose), cinnabar (0.3 g/kg, amount in AGNH) and realgar (0.3 g/kg, amount in AGNH), HgCl(2) (0.118 mmol/kg, 1/10 of cinnabar), MeHg (0.012 mmol/kg, 1/100 of cinnabar), NaAsO(2) (As(3+) 0.028 mmol/kg, 1/100 of realgar) or Na(2)HAsO(4) (As(5+) 0.056 mmol/kg, 1/50 of realgar), daily for six weeks, and nephrotoxicity was examined. Animal body weights were decreased by MeHg and HgCl(2). Blood urea nitrogen and creatinine levels were elevated by MeHg. Renal pathology was severe in the MeHg and HgCl(2) groups, moderate in the arsenite, arsenate and realgar groups and mild in the cinnabar and AGNH groups. Renal Hg accumulation in the MeHg and HgCl(2) groups was 50-200 folds higher than the cinnabar group. Expressions of metallothionein-1 and heme oxygenase-1, biomarkers for metal toxicity, were increased 2-5 folds by arsenite, arsenate, MeHg and HgCl(2), but not by realgar, cinnabar and AGNH. The chemokine and glutathione-S transferase-α4, markers for inflammation, were also increased by MeHg and HgCl(2). Expressions of cell adhesion gene S100a9 and E-cadherin were altered by HgCl(2), arsenite and realgar. Taken together, chemical forms of mercury and arsenic are major determinants in their disposition and toxicity.

Design of shared instruments to utilize simulated gravities generated by a large-gradient, high-field superconducting magnet

A high-field superconducting magnet can provide both high-magnetic fields and large-field gradients, which can be used as a special environment for research or practical applications in materials processing, life science studies, physical and chemical reactions, etc. To make full use of a superconducting magnet, shared instruments (the operating platform, sample holders, temperature controller, and observation system) must be prepared as prerequisites. This paper introduces the design of a set of sample holders and a temperature controller in detail with an emphasis on validating the performance of the force and temperature sensors in the high-magnetic field.

Nephrotoxicity of mercuric chloride, methylmercury and cinnabar-containing Zhu-Sha-An-Shen-Wan in rats

Cinnabar (HgS) is used in traditional medicines, and total Hg content is used for risk assessment of cinnabar-containing traditional medicines such as Zhu-Sha-An-Shen-Wan (ZSASW). Is ZSASW or cinnabar toxicologically similar to common mercurials? Adult Sprague-Dawley rats were gavaged with ZSASW (1.4 g/kg), cinnabar (0.2g/kg), HgCl(2) (0.02 g/kg), MeHg (0.001 g/kg), or saline daily for 60 days, and toxicity was determined. Animal body-weight gain was decreased by HgCl(2) and MeHg. Blood urea nitrogen (BUN) was increased by MeHg. Histology showed severe kidney injury following MeHg and HgCl(2) treatments, but mild after ZSASW and cinnabar. Renal Hg contents were markedly increased in the HgCl(2) and MeHg groups but were not elevated in the ZSASW and cinnabar groups. The expression of kidney injury molecule-1 was increased 50-fold by MeHg, 4-fold by HgCl(2), but was unaltered by ZSASW and cinnabar; the expression of matrilysin was increased 3-fold by MeHg. In contrast, the expression of N-cadherin was decreased by HgCl(2). Thus, ZSASW and cinnabar are much less nephrotoxic than HgCl(2) and MeHg, indicating that chemical forms of mercury underlie their disposition and toxicity.

Realgar- and cinnabar-containing an-gong-niu-huang wan (AGNH) is much less acutely toxic than sodium arsenite and mercuric chloride

An-gong-niu-huang wan (AGNH) is a famous traditional Chinese medicine used for brain trauma, hemorrhage, and coma. AGNH contains 10% realgar (As₄S₄) and 10% cinnabar (HgS). Both As and Hg are well-known for their toxic effects, and the safety of AGNH is of concern. To address this question, the acute toxicity of AGNH, realgar and cinnabar were compared to sodium arsenite (NaAsO₂) and mercuric chloride (HgCl₂). Mice were administrated orally AGNH at 1, 3 and 6g/kg. AGNH at 3g/kg contains 2.8mmol As/kg as realgar and 1.18mmol Hg/kg as cinnabar. Realgar, cinnabar, arsenite (0.28 mmol/kg, 10% of realgar) and HgCl₂ (0.256 mmol/kg, 20% of cinnabar) were orally given to mice for comparison. Blood and tissues were collected 8h later for toxicity evaluation. Serum alanine aminotransferase was increased by arsenite and blood urea nitrogen was increased by HgCl₂. Total As accumulation after arsenite in liver (100-fold) and kidney (13-fold) was much higher than that after realgar. The accumulation of Hg after HgCl₂ in liver was 400-fold higher and kidney 30-fold higher than after cinnabar. Histopathology showed moderate liver and kidney injuries after arsenite and HgCl₂, but injuries were mild or absent after AGNH, realgar, and cinnabar. The expression of metallothionein-1, a biomarker of metal exposure, was increased 4-10-fold by arsenite and HgCl₂, but was unchanged by AGNH, realgar and cinnabar. Thus, AGNH, realgar and cinnabar are much less toxic acutely than arsenite and HgCl₂. The chemical forms of As and Hg are extremely important factors in determining their disposition and toxicity.

Effect of alpha-hederin and sapindoside B on hepatic microsomal cytochrome P-450 in mice

AIM

To study the relation between the effect of alpha-hederin (Hed) and sapindoside B (Sap B) on cytochrome P-450 and their hepatoprotection.

METHODS

Mice were given sc Hed, Sap B, as well as a mixture of Hed + Sap B (1:1.5), and hepatic microsomal cytochrome P-450 was examined.

RESULTS

Hed 20 mg.kg-1, Sap B 20 mg.kg-1 and Hed + Sap B 20 mg.kg-1 sc, reduced hepatic P-450 content by 40%, 55% and 50%, respectively. The effect of the saponins on P-450 was reversible, as P-450 level returned to normal after 3 d. Phenobarbital (Phe) 50 mg.kg-1 ip increased P-450 2.5-fold, the Phe-induced P-450 was inhibited 50% by Hed + Sap B. No inhibitory effect was seen when liver microsomes were incubated with Hed + Sap B in vitro.

CONCLUSION

The hepatoprotective effects of Hed and Sap B were at least in part, due to its suppressive effect on liver cytochrome P-450.

Hemorrheological changes in chronic hepatitis and liver cirrhosis and their relations to the syndromes differentiated by traditional Chinese medicine

Blood and plasma viscosity, hematocrit and erythrocyte sedimentation rate were examined in 146 cases of chronic hepatitis and liver cirrhosis. In addition, blood fibrinogen and blood flow of the tongue and skin were studied in 123 and 46 of them respectively. The same indices were observed in 39 cases before and after treatment. The results showed definite hemorrheological patterns in different syndromes and therapeutic efficacy was also correlated with the changes in the mentioned indices. Thus it is believed that these indices of hemorrheology may serve as supplementary means for the differentiation of syndromes, evaluation of therapeutic effect and prognosis in chronic liver diseases.