Glutathione Peroxidase-Activatable Two-Photon Ratiometric Fluorescent Probe for Redox Mechanism Research in Aging and Mercury Exposure Mice Models.

Solid evidence confirms that glutathione peroxidase (GPx) is a kind of vital protease in the first-line antioxidant defense system and participates in regulation of redox homeostasis as well as the pentose phosphate pathway. However, the current methods cannot achieve real-time and in situ visualization studies of GPx. In addition, GPx is highly reactive and susceptible to external interference, and there is rare research for exploring the roles of GPx under environmental factor exposure. Herein, we report a novel two-photon ratiometric fluorescent probe (TP-SS) for GPx detection for the first time. Using TP-SS, we explore the reversible catalytic cycle and the antioxidant mechanisms of GPx/GSH redox pool in aging and mercury exposure models. We detect the concentration fluctuation of GPx in aging and mercury exposure mice models. Also, we perform GPx detection in deep brain tissue and the imaging depth up to 100 µm. We believe that the novel two-photon ratiometric fluorescent probe TP-SS can facilitate the development of GPx-targeting tools and offer great advances in exploring the physiological/pathological functions of GPx.

Mercuric chloride poisoning: symptoms, analysis, therapies, and autoptic findings. A review of the literature.

Among mercury-related intoxications, the re-emerging of mercuric chloride poisoning has been recently described in literature. Only sparse data, reporting the clinical symptoms, the anatomo-pathological findings, the analytical procedures or the treatment have been published and no exhaustive analysis of all these factors exists in literature. The classic symptoms associated with toxicity of mercuric chloride is a combination of renal, gastrointestinal (GI) and central nervous system (CNS) damages, eventually leading to death. Fatalities related to exposure to mercuric chloride have been reported since the nineteenth century. To date, there have been 45 published cases in the medical literature in which the intoxication or the death is attributed to mercuric chloride. In this review, we will describe the modern medical treatments, with particular attenztion to the developments of the lasts two decades, in order to provide an exhaustive description of the clinical symptoms, the post-mortem findings, and the analytical procedures to act out when mercuric chloride intoxication occurs. The analysis of the data obtained permitted us to accurately describe all the organs and apparatus involved in mercuric chloride intoxication. The target organs were the kidneys, the GI tract and the CNS. A description of the analytical procedures for the determination of mercuric chloride in biological materials, to carry out in vivo and in post-mortem samples has also been described.

Copper attenuates early and late biochemical alterations induced by inorganic mercury in young rats.

Mercury (Hg), a divalent metal, produces adverse effects predominantly in the renal and central nervous systems. The aim of this study was to determine the effectiveness of copper (Cu) in prevention of mercuric mercury (Hg2+)-mediated toxic effects as well as the role metallothioneins (MT) play in this protective mechanism in young rats. Wistar rats were treated subcutaneously with saline (Sal) or CuCl2.2H2O (Cu 2.6 mg/kg/day) from 3 to 7 days old and with saline or HgCl2 (Hg 3.7 mg/kg/day) from 8 to 12 days old. The experimental groups were (1) Sal-Sal, (2) Cu-Sal, (3) Sal-Hg, and (4) Cu-Hg. MTs and metal contents were determined at 13 and 33 days of age. Porphobilinogen synthase (PBG-synthase) activity as well as renal and hepatic parameters were measured at 33 days. At 13 day, Hg2+ exposure increased hepatic MT, Hg, zinc (Zn) and iron (Fe) levels, in kidney elevated Cu and Hg and decreased renal Fe concentrations, accompanied by elevated blood Hg levels. At 33 days, Hg2+ exposure inhibited renal PBG-synthase activity, increased serum urea levels and lowered Fe and Mg levels. Copper partially prevented the rise in blood Hg and liver Fe noted at 13 days; and completely blocked urea rise and diminished renal PBG-synthase activity inhibition at 33 days. In 13-day-old rats, Cu exposure redistributed the Hg in the body, decreasing hepatic and blood levels while increasing renal levels, accompanied by elevated renal and hepatic MT levels in Hg2+-exposed animals. These results suggest that hepatic MT might bind to hepatic and blood Hg for transport to the kidney in order to be excreted. ABBREVIATIONS: MT: metallothioneins; PBG-synthase: porphobilinogen synthase.

Nephroprotective potential of selenium and taurine against mercuric chloride induced nephropathy in rats.

The study was aimed to estimate whether pre-treatment with sodium selenite or taurine would reverse kidney damage induced by intraperitoneal injection of mercuric chloride in rats. Animals were divided into six groups: (1) control group; (2) sodium selenite group; (3) taurine group; (4) HgCl2 group; (5) sodium selenite pretreated group; (6) taurine pretreated group. The results demonstrated that HgCl2 causes significant enhancement in serum malondialdehyde (MDA), creatinine, N-acetyl-beta-d-glucosaminidase (NAG), cystatin C, nephrin and interleukin 6 (IL-6) levels accompanied with significant reduction in serum nitric oxide (NO) level. Pretreatment with sodium selenite or taurine produces significant depletion in MDA, NAG, cystatin C, nephrin and IL-6 levels in concomitant with significant elevation in serum NO level as compared to HgCl2 group. HgCl2 induced pathological alterations in the kidney. The ultrastructural investigation of renal cortex of HgCl2-administered group revealed that the glomerular basement membrane is uniform, the fenestrations of endothelial cells are swollen, and the secondary foot processes appear also swollen even fused at some points. The proximal convoluted tubules showed apical short and few microvilli, while, some tubular cells showed relatively normal microvilli. In contrast, sodium selenite or taurine pretreatment could significantly reduce the pathological alterations in the kidney caused by HgCl2 intoxication. The current results suggested that selenium and taurine possess nephroprotective efficacy due to their antioxidative capacity and anti-inflammatory activity.

Acute mercuric chloride poisoning at a potentially lethal dose ended with survival: symptoms, concentration in cerebrospinal fluid, treatment.

This study aims to present a case of acute mercuric chloride poisoning at a potentially lethal dose treated with the antidote - 2,3-dimercapto- 1-propanesulfonic acid (DMPS) and continuous renal replacement therapy (CRRT) combined with CytoSorb. A 21-year-old woman was admitted to a hospital with abdominal pain, vomiting, and suspected gastrointestinal bleeding after taking 5000 mg of mercuric chloride for suicidal purposes. Due to the patient deteriorating general condition and multiple organ damage, on the third day she was transported to the Clinic of Anaesthesiology and Intensive Care (CAaIC), Lódz, Poland. Laboratory tests confirmed features of acute kidney injury and high mercury levels in the blood (1051 µg/l) and urine (22 960 µg/l) - DMPS therapy and CRRT combined with CytoSorb were instituted. Due to nervous system complaints (headache, dizziness), a lumbosacral puncture was performed - the mercury concentration in the cerebrospinal fluid (CSF) was 5.45 µg/l. During a colonoscopy, significant diagnostic abnormalities revealed features of colonic mucosal necrosis. The treatment resulted in a decrease in subjective complaints, decreased mercury levels in biological material, and improved parenchymal organ function. On the 15th day of therapy, the patient was transferred to the primary care center for further treatment. The case confirms the possibility of improvement of patient condition following ingestion of a potentially lethal dose (5 g) as a result of the initiation of appropriate therapy even on the third day. The presence of mercury in CSF confirms that inorganic mercury compounds (mercuric chloride) can pass through the blood-brain barrier after oral ingestion. Int J Occup Med Environ Health. 2023;36(5):685-92.

Acute intranasal intoxication with mercuric chloride taken accidently instead of cocaine - A case report.

CONTEXT: Mercuric chloride (mercury (II) chloride) belongs to inorganic mercury compounds characterized by good water solubility and associated high toxicity. The paper describes an unusual case of intranasal intoxication with corrosive sublimate confused with cocaine by a young male. CASE REPORT: Intranasal administration of corrosive sublimate caused severe local symptoms of chemical burn within the nasal cavity. From the 2nd day the patient developed symptoms of renal dysfunction with transient polyuria and serum retention of nitrogen metabolites. The patient was undergoing chelation therapy with DMPS, N-acetylcysteine and d-penicyllamine. Four procedures of haemodialysis were performed with simultaneous DMPS and N-acetylcysteine treatment. The urine mercury level on the first day of hospitalization was 1989 µg/L, and after 26 days of treatment returned to the physiological level. During treatment renal function was normalized, the patient was discharged in general good condition. DISCUSSION: Mercuric chloride is readily absorbed from the nasal cavity. Its administration may cause intoxication manifested by both chemical burn at the exposure site and systemic symptoms, particularly renal impairment. Even in case of renal dysfunction the use of DMPS seems safe, if haemodialysis is performed at the same time. Simultaneous haemodialysis and chelation therapy may accelerate elimination of mercury from the organism.

Protective effect of mycophenolate mofetil on mercuric chloride-induced nephrotoxicity in rats.

In the present study the effect of mycophenolate mofetil (MMF), an immunosuppressant, on mercuric chloride (HgCl(2))-induced nephrotoxicity in male Wistar rats was investigated. Animals (200-250 g) were divided into five groups and were subjected to a 6-day treatment schedule. The first (control) group received only vehicle without any active drug. The second to fifth groups were administered HgCl(2) challenge (single dose of 5 mg/kg, s.c.) on the fourth day. Additionally, the second group received distilled water (DW) on all 6 days and the third group was administered DW the initial 3 days and MMF (10 mg/kg b.i.d. by oral gavage) on days 4-6. The fourth group was given DW the initial 2 days and MMF on days 3-6 and the fifth group received MMF all 6 days. All animals were euthanized on the sixth day. It was found that HgCl(2) administration caused significant nephrotoxicity, as indicated by a rise in serum creatinine, blood urea and soluble intercellular adhesion molecule 1 (sICAM-1) concentrations, histopathological injury and increased oxidative stress (altered malondialdehyde and glutathione levels) as compared to the control group. Administration of MMF significantly ameliorated HgCl(2)-induced nephrotoxicity. The results suggest the potential of MMF in preventing the acute nephrotoxicity of HgCl(2).

The role of endoplasmic reticulum stress in renal damage caused by acute mercury chloride poisoning.

Acute mercury chloride (HgCl2) poisoning may lead to kidney injury, but the underlying mechanism remains largely unknown. Endoplasmic reticulum (ER) stress plays a role in some heavy metal poisoning. Whether it mediates kidney injury in acute HgCl2 poisoning remains unknown. In this study, we examined the kidney injury and the corresponding ER stress in the mouse model of different doses of acute HgCl2 poisoning. To further confirm the role of ER stress, we tested the effects of its chemical chaperone [4-phenylbutyric acid (4-PBA)]. The results revealed that acute HgCl2 poisoning caused more severe kidney injury with dose on and activated ER stress, as indicated by increased expression of GRP78 and CHOP. Inhibition of ER stress restored the functional and morphological changes of kidneys, and partly attenuated renal tubular epithelial cell apoptosis. In summary, ER stress contributes to the acute kidney injury following HgCl2 poisoning, and inhibition of ER stress may alleviate the kidney injury via reducing apoptosis.

Acute mercury intoxication and use of chelating agents.

There is a great hazard of mercury intoxication in the third world for artisanal miners using mercury as amalgam for extracting and refining gold. In developing countries, there is the possibility of risk regarding exposure to Hg from amalgam tooth fillings, ethyl-Hg (thimerosal) added as antiseptic to vaccines and methyl-Hg in fish. In one case, a 41-year-old man attempted suicide by ingesting 100 mg of HgCl2. After 8 hours, he developed hematemesis and entered the intensive care unit; his urinary Hg was 10.1 mg/l. Treatment with 2,3-dimercaptopropanol (BAL) was started by intramuscular route after 16 hours at the dosage of 5 mg/kg body weight every 4 hours on days 2-3 and 3 mg/kg every 6 hours on days 4-5 and then every 12 hours on days 6-14 without adverse side effects. Acute Hg intoxication can be managed with BAL as first choice chelator, whereas the less toxic 2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane-1-sulfonic acid (DMPS) should be reserved for cases of less severe inorganic Hg or methyl-Hg acute intoxication. Such agents, recommended only for the treatment of acute Hg poisoning, should not be used for patients suffering from neurological diseases in which environmental Hg exposure is hypothesised.

Comparative evaluation of the protective effect of selenium and garlic against liver and kidney damage induced by mercury chloride in the rats.

The present study was designed to compare the protective effect of selenium and garlic against liver and kidney damage induced by (ip) injection of 0.5 mg/kg mercury chloride (HgCl(2)) in rats. Thirty-six Sprague-Dawley rats were used in the present experiment and divided into six groups: one group was orally given (1 ml) saline and served as a control group; two groups of rats were given either selenium (0.1 mg/kg) or garlic (63 mg/kg) alone, once daily an oral dose for 30 successive days; other two groups of rats were given either selenium or garlic alone, once daily a dose for 15 successive days prior to HgCl(2) injection and on the next 15 successive days simultaneously with HgCl(2) injection; and the last group of rats was injected ip with HgCl(2) for 15 days and at the end of the experiment (which lasted 30 days), blood samples for the biochemical analysis were obtained from all rats after being lightly anesthetized with ether, and specimens of kidney and liver were removed and prepared for histochemical study. Computer image analysis was applied to liver and kidney tissues to evaluate the DNA density and DNA ploidy pattern in different groups. The results revealed that the rats injected with HgCl(2) showed a significant increase in levels of blood urea nitrogen (BUN), serum creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST) by 29.3%, 62.5%, 29.46% and 30.61%, respectively, while alkaline phosphatase (ALP) showed a significant decrease by 22.6% as compared with saline control group. Rats that were given selenium in combination with the HgCl(2) injection showed a significant decrease in BUN, Serum creatinine, ALT and AST levels, while ALP was significantly increased as compared with HgCl(2) group. Also rats that were given garlic in combination with HgCl(2) injection showed a significant decrease in BUN, Serum creatinine, ALT and AST levels, although serum ALP level showed an increase as compared to HgCl(2) group. Rats that had been orally administered selenium or garlic alone did not show any significant changes in the serum level of BUN, Serum creatinine, ALT and AST but there was a significant decrease in ALP level as compared with saline control group. The cytometric results revealed that injection of HgCl(2) induced an increase in the DNA density in kidney tissues with an increase in aneuploid cells and decrease in diploid cells. However, DNA density decreased in liver tissues with mild decrease in diploid cells and little percentage of aneuploid cells. We can conclude that oral administration of either selenium or garlic produces a significant protection against liver and kidney damage induced by the HgCl(2) injection, but garlic appears to be more protective.

Successful treatment of potentially fatal heavy metal poisonings.

Pure inorganic heavy metal ingestions for suicidal intent are a rare occurrence. Most case reports on this subject focus on the serious neurological, hepatic, or renal side effects. We describe two cases of significant heavy metal poisonings (arsenic trioxide and mercuric chloride) that were successfully managed with aggressive decontamination and combined chelation therapy. Both chemicals were obtained in pure powder form through the Internet.

Peripheral markers of oxidative stress in chronic mercuric chloride intoxication.

The present study was designed to evaluate the time course changes in peripheral markers of oxidative stress in a chronic HgCl2 intoxication model. Twenty male adult Wistar rats were treated subcutaneously daily for 30 days and divided into two groups of 10 animals each: Hg, which received HgCl2 (0.16 mg kg(-1) day(-1)), and control, receiving the same volume of saline solution. Blood was collected at the first, second and fourth weeks of Hg administration to evaluate lipid peroxidation (LPO), total radical trapping antioxidant potential (TRAP), and superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase (CAT). HgCl2 administration induced a rise (by 26%) in LPO compared to control (143 +/- 10 cps/mg hemoglobin) in the second week and no difference was found at the end of the treatment. At that time, GST and GPx were higher (14 and 24%, respectively) in the Hg group, and Cu,Zn-SOD was lower (54%) compared to control. At the end of the treatment, Cu,Zn-SOD and CAT were higher (43 and 10%, respectively) in the Hg group compared to control (4.6 +/- 0.3 U/mg protein; 37 +/- 0.9 pmol/mg protein, respectively). TRAP was lower (69%) in the first week compared to control (43.8 +/- 1.9 mM Trolox). These data provide evidence that HgCl2 administration is accompanied by systemic oxidative damage in the initial phase of the process, which leads to adaptive changes in the antioxidant reserve, thus decreasing the oxidative injury at the end of 30 days of HgCl2 administration. These results suggest that a preventive treatment with antioxidants would help to avoid oxidative damage in subjects with chronic intoxication.

Contact sensitivity to mercuric chloride is associated with I-A region in mice.

Genetic control of contact sensitivity to mercuric chloride antigen was studied using various strains on inbred mice. Mice with class II Ab,d,f,s haplotypes showed a high magnitude of response, whereas those with class II Ak,q were low responders. These results indicate that mercuric chloride contact sensitivity may be influenced by the I-A region of H-2. Transfer experiments revealed that these responses might be mediated by L3T4+, Lyt-2- T cells. However Lyt-2+ T cells do not suppress the DTH response.

Urinary excretion of furosemide in rats with HgCl2-induced acute renal damage.

To examine the influence of mercuric chloride (HgCl2)-induced acute renal damage on urinary excretion of furosemide, HgCl2 (1 mg/kg) or its vehicle alone was given intraperitoneally to Wistar rats. The following two experiments were done. Study I: Three percent body weight (b.w.) of 1% NaCl solution or furosemide (30 mg/kg) in 3% b.w. of 1% NaCl solution was given orally before and after HgCl2 treatment, and an 8-hour urine was collected. Study II: Furosemide (30 mg/kg) was given orally, and blood samples were obtained at 1, 2, 3, 4, 6 and 8 hours after administration. Urinary excretion of N-acetyl-beta-D-glucosaminidase increased, and urine volume and urinary excretions of furosemide and sodium decreased in the HgCl2-treated rats. There were significant correlations between the urinary furosemide and its diuretic effects. Regression lines after HgCl2 were significantly different from those before treatment. The values of absorption as well as elimination rate constant were smaller, while the time to maximum concentration and the elimination half-life were longer in the HgCl2-treated rats compared to vehicle-treated animals. These results suggest that the urinary excretion of furosemide and the responsiveness of renal tubular cells to this agent are impaired in rats with HgCl2-induced acute renal damage.

The determination of toxic metals in simulated stomach contents by energy dispersive X-ray fluorescence analysis and a fatal case of mercury poisoning.

Soup is used as a simulated stomach contents matrix to determine the lower level of detection for 16 metals. All of the metals can be detected at the levels which might be expected for acute fatal doses even if the stomach contents are considerably diluted. However where small doses are administered over a prolonged period this method may not be sufficiently sensitive. A case of fatal poisoning by the ingestion of mercuric chloride is described to illustrate the effectiveness of the method. In this case mercury was also detected and determined at highly significant levels in blood and liver by the same technique. This energy dispersive X-ray fluorescence (EDXRF) method is easy to use, rapid and non-destructive.

Distribution of 5'-nucleotidase in the tissues of sheep and the effect of kidney and liver lesions on the activity of the enzyme in plasma and urine.

The distribution of 5'-nucleotidase (5'-NT) activity in the tissues of the sheep differs from that of gamma glutamyl transferase (GGT). Nevertheless, both enzymes are released into the plasma of sheep which have been infected with Fasciola hepatica or in which the bile duct has been ligated. In a sheep dosed with sporidesmin, a fungal toxin which damages the biliary tract, there was an increase in GGT activity in the plasma and urine but no change in 5'-NT activity. Neither enzyme was released into the plasma or urine of sheep dosed with carbon tetrachloride. In sheep with renal tubular necrosis and hepatocellular necrosis caused by dosage with hexachlorobutadiene, both enzymes were released into the plasma, and GGT, but not 5'-NT activity was found in urine. In sheep with tubular necrosis of the kidney caused by the administration of mercuric chloride, GGT activity, but not 5'-NT, increased in the plasma and urine.

Spectrum of poisoning requiring haemodialysis in a tertiary care hospital in India.

We report our experience in 66 cases of acute poisoning requiring haemodialysis (HD) in the last 17 years. Barbiturate poisoning was the commonest poisoning (30 cases). Mean blood barbiturate level was 8.9 mg%. Twenty four were in grade IV coma at the time of presentation. Twenty five required one HD and 5 cases needed 2 HD. Four died due to respiratory infection or hypotension. Copper sulphate poisoning was encountered in 19 cases. Common features in this group were: acute renal failure (ARF) (19), haematuria (3), gastrointestinal bleeding (7), intravascular haemolysis (9), jaundice (11), hepatocellular toxicity (8), methaemoglobinuria (8) and circulatory collapse (5). The indication for HD in all these cases was ARF. Seven patients died. There were 9 cases of mercuric chloride poisoning requiring 2-5 HD. Common features in this group were; ARF (9), gastrointestinal bleeding (9), anaemia (8), jaundice (2). Two patients died. Other patients had Mandrax, Naphthalene, Tincture Iodine, Ethylene Bromide and Lithium poisoning. Overall mortality in our study was 24.2%. It is concluded that HD is not the primary mode of therapy for drug intoxication. Adequate supportive management is most important in determining final outcome of these patients.

The topography of mercurial lymphadenopathy in brown Norway rats.

Injection of mercuric chloride caused a progressive systemic lymphadenopathy and splenomegaly in Brown Norway (BN) but not in Lewis rats, as reported by others. We studied the number, duration and route of HgCl2 treatments and the topography of the resultant lymphadenopathy, as well as its age and strain dependency. Five injections of HgCl2 increased three-fold the weight of the lymph nodes which became considerably heavier than the spleen. Weanling rats were less susceptible than adults. A regional lymphadenopathy could not be produced. However, a synergistic interaction was observed when the systemic effects of HgCl2 were added to the regional lymphadenopathy produced by injections of metal powders, such that the lymph node mass approached 2% of body weight.

An acute mercuric mercury poisoning: chemical speciation of hair mercury shows a peak of inorganic mercury value.

A woman ingested a dose of sublimate (approximately 0.9 g) in an attempted suicide. She survived and recovered in response to a combination of therapies including chelate (BAL) therapy, plasma exchange, haemodialysis and peritoneal dialysis. Serum inorganic mercury concentration, urinary inorganic mercury excretion and hair inorganic and organic mercury and selenium concentrations, along the length from the scalp to the distal part, were measured. Longitudinal analysis of hair, revealed a peak in inorganic mercury corresponding to the time of mercury ingestion. Organic mercury and selenium in the hair had different patterns of longitudinal variation from that of inorganic mercury. The biological half-life (23.5 d) of serum inorganic mercury levels was in good agreement with values previously reported in the literature.

Housing conditions affect susceptibility to mercury in the golden hamster.

Individually-housed and group-housed golden hamsters (Mesocricetus auratus), aged 8 weeks, were studied with regard to their susceptibility to a single gavage of mercuric chloride (10 mg/kg body weight). Body weight and food consumption were measured for 10 days (day -9 to day 0) in a pre-application period and for 13 days (day 1 to day 13) in a post-application period. Mercuric chloride administration significantly reduced body weight gain in both isolated and grouped hamsters at day 1 compared to vehicle controls. While the individually-housed treated hamsters recovered during the post-application period, the group-housed treated hamsters showed a reduced body weight gain over the whole post-application period. Results are discussed in relation to elevated susceptibility to intoxication in group-housed hamsters triggered by high social stress. This study highlights the need to carefully consider the housing conditions which can influence the results of teratological experiments.