In this study, we used a rat model of pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT) to investigate the role and mechanism of angiotensin (Ang)-(1-7) in regulating pulmonary artery diastolic function. Three weeks after subcutaneous injection of MCT or normal saline, the right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) of rats were detected using a right heart catheter. Vascular endothelium-dependent relaxation was evaluated by acetylcholine (ACh)-induced vasodilation. The relaxation function of vascular smooth muscle was evaluated by sodium nitroprusside (SNP)-induced vasodilation. Human pulmonary artery endothelial cells (HPAECs) were incubated with Ang-(1-7) to measure nitric oxide (NO) release levels. The results showed that compared with control rats, RVSP and RVHI were significantly increased in the MCT-PAH rats, and both ACh or SNP-induced vasodilation were worsened. Incubation of pulmonary artery of MCT-PAH rats with Ang-(1-7) (1 × 10^-9-1 × 10^-4 mol/L) caused significant vaso-relaxation. Pre-incubation of Ang-(1-7) in the pulmonary artery of MCT-PAH rats significantly improved ACh-induced endothelium-dependent relaxation, but had no significant effect on SNP-induced endothelium-independent relaxation. In addition, Ang-(1-7) treatment significantly increased NO levels in HPAECs. The Mas receptor antagonist A-779 inhibited the effects of Ang-(1-7) on endothelium-dependent relaxation and NO release from endothelial cells. The above results demonstrate that Ang-(1-7) promotes the release of NO from endothelial cells by activating Mas receptor, thereby improving the endothelium-dependent relaxation function of PAH pulmonary arteries.
Rats ; Humans ; Animals ; Vasodilation ; Pulmonary Arterial Hypertension ; Monocrotaline/toxicity* ; Rats, Sprague-Dawley ; Hypertension, Pulmonary/chemically induced* ; Endothelial Cells ; Pulmonary Artery ; Endothelium ; Acetylcholine/pharmacology* ; Nitroprusside/pharmacology*

Introduction: Small-scale mining (SSM) is mining by individuals, groups, families, or cooperatives with minimal or no mechanization, often in the market's informal (illegal) sector. According to the Mines and Geosciences Bureau (MGB) in the Philippines, the gross production value of small-scale mining as of the 1st to 3rd quarter of 2020 was 0.5 billion pesos (1.05 billion USD). Objectives: This study investigated the work process in small-scale mining in the northern part of the Philippines. It documented the occupational hazards that small-scale gold miners are exposed to in each of the work processes. Methods: The target population is a community in the northern Philippines where the majority of the males are engaged in small-scale gold mining. This qualitative study used work observation and hazards analysis tools to investigate small-scale miners' work processes and hazard exposures. Results: The most widely employed mining technique in the target community is dog-hole mining consisting of several sub-processes: tunneling, ball milling, and gravity concentration, cyanide leaching, and smelting. The occupational hazards identified were noise exposure from the dynamite blast, temperature extremes, and exposure to dust from dynamite blasting. The small-scale miners were subjected to prolonged crouching and bending, handling tools, and carrying heavy sacks filled with mineral ores. The miners resorted to improvised protective equipment such as wearing sleeveless shirts and drinking water for temperature extremes, distancing themselves from the mining blasts during dynamite blasting, and intermittently used carts with manual handling to transport ores packed in sacks. In the ball milling and gravity concentration process, machine-related accidents such as cuts from the crusher were observed. In cyanide leaching, which uses massive amounts of cyanide, the most prevalent hazards were heat, dust, and chemicals such as cyanide fumes. The risks included smoke from burning ore and coal and exposure to borax and nitric acid fumes in the smelting process. Conclusion This study documented the work process in small-scale gold mining and the hazard exposures in this type of informal industry. It is suggested that the local and national governments implement intervention programs for occupational health and safety measures, and social security nets are provided for the small-scale miners in Itogon, Benguet.
Cyanides ; Occupational Health

Atropa belladonna seedlings were used as experimental materials and cultivated by soil culture method. Different concentrations(0,0.05,0.1,0.2,0.5 mmol·L~(-1))of NO donor sodium nitroprusside(SNP) were sprayed on the leaves. The effects of different concentrations of SNP and different treatment time(4,8,12,16 d) on nitrogen metabolism, secondary metabolite content, precursor content of tropane alkaloid synthesis pathway and expression of key enzyme genes under 100 mmol·L~(-1) NaCl stress were studied. The results showed that with the prolongation of salt stress, the nitrogen metabolism and the accumulation of secondary metabolites of A. belladonna were inhibited to some extent. After treatment with different concentrations of exogenous SNP, the ammonium nitrogen content decreased dramatically, and the contents of nitrate nitrogen, free amino acid, soluble protein and the activities of key enzymes of nitrogen metabolism(NR, GS, GDH) were all greatly improved; the contents of precursor amino acids(ornithine, arginine) and polyamines(Put, Spd, Spm) in the secondary metabolic pathway have increased to varying degrees. The qRT-PCR analysis showed that exogenous SNP treatment can effectively promote the high expression of key enzyme genes PMT, TRⅠ and H6H in the secondary metabolic pathway of A. belladonna, and the production of hyoscyamine and scopolamine were increased notably. In summary, the application of appropriate concentration of SNP can effectively alleviate the inhibition of salt stress on the nitrogen metabolism and secondary metabolism of Atropa belladonna, and enhance its salt tolerance. Overall, 0.1 mmol·L~(-1) and 0.2 mmol·L~(-1) SNP treatment achieved the most remarkable effect.
Atropa belladonna/metabolism* ; Hyoscyamine/analysis* ; Nitrogen/metabolism* ; Nitroprusside ; Scopolamine/analysis* ; Secondary Metabolism ; Sodium Chloride ; Stress, Physiological

OBJECTIVES: Excitability o medial vestibular nucleus (MVN) in the brainstem can be affected by changes in the arterial blood pressure. Several animal studies have demonstrated that acute hypotension results in the alteration of multiunit activities and expression of cFos protein in the MVN. In the field of extracellular electrophysiological recording, tetrode technology and spike sorting algorithms can easily identify single unit activity from multiunit activities in the brain. However, detailed properties of electrophysiological changes in single unit of the MVN during acute hypotension have been unknown. METHODS: Therefore, we applied tetrode techniques and electrophysiological characterization methods to know the effect of acute hypotension on single unit activities of the MVN of rats. RESULTS: Two or 3 types of unit could be classified according to the morphology of spikes and firing properties of neurons. Acute hypotension elicited 4 types of changes in spontaneous firing of single unit in the MVN. Most of these neurons showed excitatory responses for about within 1 minute after the induction of acute hypotension and then returned to the baseline activity 10 minutes after the injection of sodium nitroprusside. There was also gradual increase in spontaneous firing in some units. In contrast small proportion of units showed rapid reduction of firing rate just after acute hypotension. CONCLUSIONS: Therefore, application of tetrode technology and spike sorting algorithms is another method for the monitoring of electrical activity of vestibular nuclear during acute hypotension.
Animals ; Arterial Pressure ; Brain ; Brain Stem ; Fires ; Hypotension ; Methods ; Neurons ; Nitroprusside ; Rats ; Vestibular Nuclei

Dipeptidyl peptidase4 (DPP4) inhibitors such as gemigliptin are anti-diabetic drugs elevating plasma concentration of incretins such as GLP-1. In addition to the DPP4 inhibition, gemigliptin might directly improve the functions of vessels under pathological conditions. To test this hypothesis, we investigated whether the acetylcholine-induced endothelium dependent relaxation (ACh-EDR) of mesenteric arteries (MA) are altered by gemigliptin pretreatment in Spontaneous Hypertensive Rats (SHR) and in Wistar-Kyoto rats (WKY) under hyperglycemia-like conditions (HG; 2 hr incubation with 50 mM glucose). ACh-EDR of WKY was reduced by the HG condition, which was significantly recovered by 1 µM gemigliptin while not by saxagliptin and sitagliptin up to 10 µM. The ACh-EDR of SHR MA was also improved by 1 µM gemigliptin while similar recovery was observed with higher concentration (10 µM) of saxagliptin and sitagliptin. The facilitation of ACh-EDR by gemigliptin in SHR was not observed under pretreatment with NOS inhibitor, L-NAME. In the endotheliumdenuded MA of SHR, sodium nitroprusside induced dose-dependent relaxation was not affected by gemigliptin. The ACh-EDR in WKY was decreased by treatment with 30 µM pyrogallol, a superoxide generator, which was not prevented by gemigliptin. Exendin-4, a GLP-1 analogue, could not enhance the ACh-EDR in SHR MA. The present results of ex vivo study suggest that gemigliptin enhances the NOS-mediated EDR of the HG-treated MA as well as the MA from SHR via GLP-1 receptor independent mechanism.
Animals ; Endothelium ; Glucagon-Like Peptide 1 ; Glucagon-Like Peptide-1 Receptor ; Hyperglycemia ; Hypertension ; Incretins ; Mesenteric Arteries* ; NG-Nitroarginine Methyl Ester ; Nitroprusside ; Plasma ; Pyrogallol ; Rats ; Rats, Inbred SHR* ; Relaxation ; Sitagliptin Phosphate ; Superoxides ; Vasodilation*

OBJECTIVE: To investigate the efficacy of prussian blue (PB) or its combination with hemoperfusion (HP) in the treatment of acute thallium poisoning. METHODS: Forty-seven patients with acute thallium poisoning with complete data hospitalized in the 307th Hospital of PLA from September 2002 to December 2017 were enrolled, and they were divided into mild poisoning group (blood thallium < 150 μg/L, urinary thallium < 1 000 μg/L) and moderate-severe poisoning group (blood thallium ≥ 150 μg/L, urinary thallium ≥ 1 000 μg/L) according to the toxic degrees. All patients were given symptomatic supportive treatments such as potassium supplementation, catharsis, vital organ protections, neurotrophic drugs, and circulation support. The mild poisoning patients were given PB with an oral dose of 250 mg×kg^-1×d^-1, while moderate-severe poisoning patients were given PB combined HP continued 2-4 hours each time. The PB dose or frequency of HP application was adjusted according to the monitoring results of blood and urine thallium. Data of gender, age, pain grading (numeric rating scale NRS), clinical manifestations, blood and urine thallium before and after treatment, length of hospitalization and prognosis were collected. RESULTS: Of the 47 patients, patients with incomplete blood and urine test results, and used non-single HP treatment such as plasmapheresis and hemodialysis for treatment were excluded, and a total of 29 patients were enrolled in the analysis. (1) Among 29 patients, there were 20 males and 9 females, median age of 40.0 (34.0, 49.0) years old; the main clinical manifestations were nervous system and alopecia, some patients had digestive system symptoms. There were 13 patients (44.8%) in the mild poisoning group with painless (grade 0) or mild pain (grade 1-3) with mild clinical symptoms, the length of hospitalization was 17.0 (14.2, 21.5) days. There were 16 patients (55.2%) in the moderate-severe poisoning group with moderate pain (grade 4-6) or severe pain (grade 7-10) with severe clinical symptoms, the length of hospitalization was 24.0 (18.0, 29.0) days. (2) After treatment, the thallium concentrations in blood and urine in the mild poisoning group were significantly lower than those before treatment [μg/L: blood thallium was 0.80 (0, 8.83) vs. 60.00 (40.00, 120.00), urine thallium was 11.30 (0, 70.10) vs. 370.00 (168.30, 610.00), both P < 0.01], the thallium concentrations in blood and urine in the moderate-severe poisoning group were also significantly lower than those before treatment [μg/L: blood thallium was 6.95 (0, 50.50) vs. 614.50 (245.00, 922.00), urinary thallium was 20.70 (1.95, 283.00) vs. 5 434.00 (4 077.20, 10 273.00), both P < 0.01]. None of the 29 patients died, and their clinical symptoms were improved significantly. All the 27 patients had good prognosis without sequela in half a year follow-up, and 2 patients with severe acute thallium poisoning suffered from nervous system injury. CONCLUSIONS In the acute thallium poisoning patients, on the basis of general treatment, additional PB in mild poisoning group and PB combined with HP in moderate-severe poisoning group can obtain satisfactory curative effects.
Adult ; Female ; Ferrocyanides ; Heavy Metal Poisoning ; Hemoperfusion ; Humans ; Male ; Middle Aged ; Thallium/poisoning*

Iron accumulation in the brain is associated with the pathogenesis of Parkinson's disease (PD). Misexpression of some iron transport and storage proteins is related to iron dyshomeostasis. Iron regulatory proteins (IRPs) including IRP1 and IRP2 are cytosolic proteins that play important roles in maintaining cellular iron homeostasis. F-box and leucine-rich repeat protein 5 (FBXL5) is involved in the regulation of iron metabolism by degrading IRP2 through the ubiquitin-proteasome system. Nitric oxide (NO) enhances the binding activity of IRP1, but its effect on IRP2 is ambiguous. Therefore, in the present study, we aim to determine whether sodium nitroprusside (SNP), a NO donor, regulates FBXL5 and IRP2 expression in cultured SH-SY5Y cells. MTT assay revealed that treatment of SNP attenuated the cell viability in a dose-dependent manner. Flow cytometry test showed that 100 and 300 μmol/L SNP administration significantly reduced the mitochondrial membrane potential by 45% and 60%, respectively. Moreover, Western blotting analysis demonstrated that 300 μmol/L SNP significantly increased FBXL5 expression by about 39%, whereas the expression of IRP2 was decreased by 46%, correspondingly. These findings provide evidence that SNP could induce mitochondrial dysfunction, enhance FBXL5 expression and decrease IRP2 expression in SH-SY5Y cells.
Cell Line ; Cell Survival ; F-Box Proteins ; metabolism ; Homeostasis ; Humans ; Iron Regulatory Protein 2 ; metabolism ; Nitric Oxide ; metabolism ; Nitroprusside ; pharmacology ; Proteasome Endopeptidase Complex ; Ubiquitin ; metabolism ; Ubiquitin-Protein Ligase Complexes ; metabolism

BACKGROUND AND OBJECTIVES: The overall purpose of this study was to investigate the role of cytochrome C oxidase (CcO) in preventing ischemia reperfusion-induced cardiac injury through gaseous signaling molecule pathways. MATERIALS AND METHODS: We used CcO inhibitor, potassium cyanide (KCN) to mimic the pre-treatment of gaseous signaling molecules in a global ischemia/reperfusion (IR) injury model in rats. Intracellular reactive oxygen species (ROS) was determined by measuring mitochondrial H2O2 and mitochondrial complex activity. RESULTS: KCN pre-treatment led to decreased infarction area after IR injury and improved cardiac function. KCN pre-treated group challenged with IR injury was associated with reduced ROS production through inhibition of activity and not downregulation of CcO expression. In addition, KCN pre-treatment was associated with enhanced expression and activity of mitochondrial antioxidase, suggesting the role of CcO in regulating IR injury through oxidative stress. CONCLUSION: KCN pre-treatment reduced the severity of IR injury. The potential mechanism could be increased endogenous anti-oxidase activity and consequently, the enhanced clearance of ROS.
Animals ; Cytochromes c* ; Cytochromes* ; Down-Regulation ; Electron Transport Complex IV* ; Infarction ; Ischemia* ; Mitochondria ; Myocardial Infarction ; Oxidative Stress ; Potassium Cyanide ; Rats ; Reactive Oxygen Species ; Reperfusion Injury*

Antihypertensive effects of ethanol extracts of Aralia elata (Miq.) Seem. (AE) were investigated in spontaneously hypertensive rats (SHR). SHR aged 14 weeks were treated for 8 weeks with AE (10 or 50 mg/kg/day) or amlodipine besylate (Am; 10 mg/kg/day) orally. Hypertension results in injury to several organs and can produce a significant increase in malondialdehyde (MDA) content as a result of lipid peroxidation and endothelial dysfunction. In this study, oral administration of AE and Am significantly reduced systolic blood pressure, organ weight index, and MDA content in tissues but increased significantly the plasma nitrite and nitrate concentrations. The endothelium-dependent relaxant activities of acetylcholine (10⁻¹⁰–10⁻³ M) in norepinephrine (NE)-precontracted aorta were increased in AE- and Am-treated rats. Particularly strong endothelium-dependent relaxant activities were observed in AE-treated (50 mg/kg) rats. The endothelium-independent relaxant activities of sodium nitroprusside (10⁻¹⁰–10⁻³ M) in NE-precontracted aorta were not changed. The results of this study suggest that AE has both antihypertensive and end-organ protective effects in SHR.
Acetylcholine ; Administration, Oral ; Amlodipine ; Animals ; Aorta ; Aralia* ; Blood Pressure ; Ethanol* ; Hypertension ; Lipid Peroxidation ; Malondialdehyde ; Nitroprusside ; Norepinephrine ; Organ Size ; Plasma ; Rats ; Rats, Inbred SHR*

Orthostatic hypotension (OH) is associated with symptoms including headache, dizziness, and syncope. The incidence of OH increases with age. Attenuation of the vestibulosympathetic reflex (VSR) is also associated with an increased incidence of OH. In order to understand the pathophysiology of OH, we investigated the physiological characteristics of the VSR in the disorder. We applied sodium nitroprusside (SNP) to conscious rats with sinoaortic denervation in order to induce hypotension. Expression of pERK in the intermediolateral cell column (IMC) of the T4~7 thoracic spinal regions, blood epinephrine levels, and blood pressure were evaluated following the administration of glutamate and/or SNP. SNP-induced hypotension led to increased pERK expression in the medial vestibular nucleus (MVN), rostral ventrolateral medullary nucleus (RVLM) and the IMC, as well as increased blood epinephrine levels. We co-administered either a glutamate receptor agonist or a glutamate receptor antagonist to the MVN or the RVLM. The administration of the glutamate receptor agonists, AMPA or NMDA, to the MVN or RVLM led to elevated blood pressure, increased pERK expression in the IMC, and increased blood epinephrine levels. Administration of the glutamate receptor antagonists, CNQX or MK801, to the MVN or RVLM attenuated the increased pERK expression and blood epinephrine levels caused by SNP-induced hypotension. These results suggest that two components of the pathway which maintains blood pressure are involved in the VSR induced by SNP. These are the neurogenic control of blood pressure via the RVLM and the humoral control of blood pressure via epinephrine release from the adrenal medulla.
6-Cyano-7-nitroquinoxaline-2,3-dione ; Adrenal Medulla ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid ; Animals ; Blood Pressure ; Denervation ; Dizocilpine Maleate ; Dizziness ; Epinephrine ; Excitatory Amino Acid Antagonists ; Glutamic Acid ; Headache ; Hypotension* ; Hypotension, Orthostatic ; Incidence ; N-Methylaspartate ; Nitroprusside ; Rats* ; Receptors, Glutamate ; Reflex* ; Spinal Cord Lateral Horn ; Syncope ; Vestibular Nuclei