Mercury species analysis and tissue distribution in rats after continuous administration of Cinnabaris / 中国中药杂志

Cinnabaris is a traditional Chinese medicine(TCM) commonly used for sedation and tranquilization in clinics, and its safety has always been a concern. This study intends to investigate the species and tissue distribution of mercury in rats after continuous administration of Cinnabaris. In the experiment, 30 rats were randomly divided into the control group(equivalent to 0.5% carboxy-methyl cellulose sodium), low-dose Cinnabaris group(0.2 g·kg~(-1)), high-dose Cinnabaris group(2 g·kg~(-1)), pseudogerm-free control group(equivalent to 0.5% sodium carboxymethyl cellulose), and pseudogerm-free Cinnabaris group(2 g·kg~(-1)). They were orally administered for 30 consecutive days. Ultrasound-assisted acid extraction method combined with high performance liquid chromatography and inductively coupled plasma-mass spectrometry(HPLC-ICP-MS) was adopted to determine inorganic mercury [Hg(Ⅱ)], methylmercury(MeHg), and ethylmercury(EtHg) in different tissue, plasma, urine, and feces of rats. The optimal detection conditions and extraction methods were optimized, and the linearity(R~2>0.999 3), precision(RSD<7.0%), and accuracy(spike recoveries ranged from 73.05% to 109.5%) of all the mercury species were satisfied, meeting the requirements of analysis. The results of mercury species detection showed that Hg(Ⅱ) was detected in all the tissue of the five experimental groups, and the main accumulating organs were the intestinal tract, stomach, and kidney. MeHg existed at a low concentration in most tissue, and EtHg was not detected in all groups. In addition, pathological examination results showed that hepatocyte vacuolar degeneration, loose cytoplasm, light staining, and mononuclear cell infiltration were observed in the high-dose Cinnabaris group, low-dose Cinnabaris group, and pseudogerm-free Cinnabaris group, with slightly milder lesions in the low-dose Cinnabaris group. Hydrous degeneration of renal tubular epithelium could be seen in the high-dose Cinnabaris group and pseudogerm-free Cinnabaris group, but there was no significant difference between the other groups and the control group. No abnormal changes were found in the brain tissue of rats in each group. This paper studied the different mercury species and tissue distribution in normal and pseudogerm-free rats after continuous administration of Cinnabaris for 30 days and clarified its effects on the tissue structure of the liver, kidney, and brain, which provided supporting evidence for the safety evaluation of Cinnabaris.

Mercury distribution in different tissues and trophic levels of fish from a tropical reservoir, Brazil

Concentrations of organic (OrgHg) and inorganic mercury (InorgHg) were assessed in different fish tissues (liver, muscle, kidney, gut and gonads) and trophic levels collected in an impacted tropical reservoir in southeastern Brazil. Organic mercury concentrations in muscle were remarkably higher in the carnivorous species Hoplias malabaricus and Oligosarcus hepsetus. The ratios of OrgHg in relation to total mercury ( percentOrgHg) in muscle also varied according to the species trophic level: 93 percent for carnivores, 84 percent for omnivores, 73 percent for algivores/planktivores and 58 percent for detritivores. The percentOrgHg in the gut tissue of carnivores (78 percent) was much higher than that found in omnivores (30 percent), possibly reflecting a process of trophic biomagnification in the reservoir. On the other hand, the InorgHg concentrations in muscle decreased with the trophic level increase, suggesting that this form of mercury did not biomagnify through the food web. Gonads contained the least total mercury, and approximately all of this mercury was represented by the organic form (83 to 98 percent). The kidney and the liver of all fish species contained less than 50 percent OrgHg. We suggest that the low percentOrgHg in the liver is related to different capacities or strategies of OrgHg detoxification by the fish.(AU)

Concentrações de mercúrio orgânico (OrgHg) e inorgânico (InorgHg) foram avaliadas em diferentes tecidos e níveis tróficos de peixes (fígado, músculo, rim, trato digestivo e gônadas) coletados em um reservatório tropical impactado, no sudeste do Brasil. Concentrações de OrgHg no músculo foram notavelmente maiores em carnívoros (Hoplias malabaricus e Oligosarcus hepsetus). As porcentagens de OrgHg em relação ao mercúrio total ( por centoOrgHg) no músculo também variaram de acordo com o nível trófico das espécies: 93 por cento para os carnívoros, 84 por cento para os onívoros, 73 por cento para os algívoros/planctívoros e 58 por cento para os peixes detritívoros. Além disso, a por centoOrgHg encontrada no trato digestivo dos peixes carnívoros (78 por cento) foi substancialmente superior a encontrada nos onívoros (30 por cento), possivelmente refletindo um processo de biomagnificação trófica no reservatório. Por outro lado, as concentrações de InorgHg no músculo diminuíram com o aumento do nível trófico, sugerindo que esta forma do mercúrio não biomagnificou ao longo da cadeia alimentar. As gônadas apresentaram as menores concentrações de mercúrio total e grande parte deste estava na forma orgânica (83 a 98 por cento). Por outro lado, rins e fígado de todas as espécies de peixes apresentaram menos que 50 por cento de OrgHg. Sugere-se que a baixa por centoOrgHg no fígado possa estar relacionada às diferentes capacidades ou estratégias de destoxificação do OrgHg nesses peixes(AU)