Effect Of MgSO4 Research Articles

Effect of MgSO4 as a complement to NPK fertilizer on shallot growth

Climate change has a significant impact on crop failure and agricultural production. To overcome this issue, fertilization strategy is needed to increase plant growth. Magnesium Sulphate (MgSO4) role in photosynthesis, enzyme activation, and synergism with other nutrients plays big part in increasing plant growth and harvest. Complementing NPK fertilizing with MgSO4 can be a solution to fulfill nutrient needs with lower input and higher effectivity. This study aims to find best formula of MgSO4 complementing NPK fertilizer in improving shallot growth. Experimental method was conducted using Randomized Complete Group Design (RCBD) with 9 treatments and 3 replications, namely: control, standard NPK (Urea 250 kg ha-1, SP-20 130 kg ha-1, and KCL 60 kg ha-1), MgSO4 (300 kg ha-1), and six combinations of MgSO4 with NPK. The results showed that application of MgSO4 combined with NPK fertilizer significantly increases the growth of shallots. The addition of 300 kg ha-1 of MgSO4 with 3/4 doses of NPK fertilizer effectively increased shallot growth as indicated by the highest plant height, number of leaves, and number of tillers.

Effect of MgSO4·7H2O on the hydration of Portland cement

MgSO4 is usually found in the groundwater or seawater and can influence the early hydration of Portland cement. In this paper, the reaction kinetics of the early hydration of the MgSO4·7H2O + Portland cement clinker (MPC) was revealed compared with the CaSO4·2H2O + Portland cement clinker (OPC) by means of isothermal calorimetry, chemical shrinkage and solid–liquid phase analysis. The test results indicated that MgSO4·7H2O had more pronounced retarding effect on Portland cement clinker hydration than CaSO4·2H2O. The MPC system had longer initial time and final time than OPC system. In the initial period and induction period of MPC system, Mg(OH)2 and CaSO4·2H2O precipitated on not only the C3A partials but also on the C3S partials, and prevented the flash-set of clinker. The early hydration of C3A and C3S were both retrained by the combined retardation of Mg(OH)2, CaSO4·2H2O and hydration products, which resulted to a slower hydration rate of MPC than OPC before the deceleration period. The intense hydration of C3A and C3S were postponed and appeared in the deceleration period of MPC compared with OPC, which ultimately caused a deeper hydration of MPC than OPC.

Effects of MgSO4 Alone or Associated with 4-PBA on Behavior and White Matter Integrity in a Mouse Model of Cerebral Palsy: A Sex- and Time-Dependent Study.

Cerebral palsy (CP) is defined as permanent disorders of movement and posture. Prematurity and hypoxia-ischemia (HI) are risk factors of CP, and boys display a greater vulnerability to develop CP. Magnesium sulfate (MgSO4) is administered to mothers at risk of preterm delivery as a neuroprotective agent. However, its effectiveness is only partial at long term. To prolong MgSO4 effects, it was combined with 4-phenylbutyrate (4-PBA). A mouse model of neonatal HI, generating lesions similar to those reported in preterms, was realized. At short term, at the behavioral and cellular levels, and in both sexes, the MgSO4/4-PBA association did not alter the total prevention induced by MgSO4 alone. At long term, the association extended the MgSO4 preventive effects on HI-induced motor and cognitive deficits. This might be sustained by the promotion of oligodendrocyte precursor differentiation after HI at short term, which led to improvement of white matter integrity at long term. Interestingly, at long term, at a behavioral level, sex-dependent responses to HI were observed. This might partly be explained by early sex-dependent pathological processes that occur after HI. Indeed, at short term, apoptosis through mitochondrial pathways seemed to be activated in females but not in males, and only the MgSO4/4-PBA association seemed to counter this apoptotic process.

Long-term effects of prophylactic MgSO4 in maternal immune activation rodent model at adolescence and adulthood.

The effects of MgSO4 as an anti-inflammatory agent in pregnant women have been investigated in the last few years. Infections can cause an inflammatory reaction involving the placenta membranes and amniotic cavity. They may have short-term effects on the mother and her fetuses, like preterm birth, cerebral palsy, and developmental delay. Despite the alleged advantages of MgSO4 as a neuroprotective agent in the preterm brain, the long-term molecular and behavioral function of MgSO4 has not been fully elucidated. Here, we investigated the long-term effect of antenatal MgSO4 , during late gestation, on offspring's behavior focusing on cognitive function, motor activity, and social cognition in adolescence and adulthood, and explored its influence on brain gene expression (e.g., ErbB signaling, pro-inflammatory, and dopaminergic markers) in adulthood. A significant abnormal exploratory behavior of offspring of MgSO4 -treated dams was found compared to the control group in both adolescence and adulthood. Furthermore, we found that adult females exposed to MgSO4 under inflammation displayed working and recognition memory impairment. A reduction in IL-6 expression was detected in the prefrontal cortex, and hippocampus specimens derived from LPS-Mg-treated group. In contrast, an imbalanced expression of dopamine 1 and 2 receptors was detected only in prefrontal cortex specimens. Besides, we found that MgSO4 ameliorated the overexpression of the Nrg1 and Erbb4 receptors induced by LPS in the hippocampus. Thus, MgSO4 treatment for preventing brain injuries can adversely affect offspring cognition behavior later in life, depending on the sex and age of the offspring.

The effect of MgSO4 and CaSO4 on seedlings of forage crops under environmental stress

The effect of MgSO4 and CaSO4 on seedlings of forage crops under environmental stress

Analysis of the Effect of Giving MgSO4 to Mothers with Severe Preeclampsia in Pre-Referral Health Facilities at Jombang General Hospitals on the Prevalence of Eclampsia

In Indonesia, eclampsia is a major cause of maternal death. Eclampsia can be prevented by administering MgSO4 immediately after the diagnosis of severe preeclampsia. However, there are still pre-referral health facilities that do not provide MgSO4 to severe pre-eclampsia mothers. The purpose of this study was to determine the effect of giving MgSO4 to mothers giving birth with severe preeclampsia at the pre-referral health facility at RSUD Jombang on the prevalence of eclampsia. This study is an analytical study using a retrospective cohort design. Based on the estimated sample, 74 mothers were taken from the total population of 119 mothers. The sampling method used simple random sampling. Test analysis using chi square test and Fisher's exact test. Meanwhile, the chance of exposure to risk factors is assessed using Relative Risk (RR). The results of the analysis prove that 2 = 1.014; p = 0.000 which means that there is an effect of MgSO4 on the prevalence of preeclampsia. The results of further analysis obtained a relative risk value (RR) of 1.03, which means that the risk of eclampsia was 1.03 times greater in the group that was not given MgSO4 pre-referral at the site than the mother who was given MgSO4. The conclusion obtained in this study is that there is an effect of giving MgSO4 to mothers giving birth with severe pre-eclampsia at the pre-referral PONEK RSUD Jombang on the occurrence of eclampsia.

The addition of magnesium sulfate and borax to urea reduced soil NH3 emissions but increased N2O emissions from soil with grass

Nitrogen (N) use efficiency can be increased by the addition of substances to urea. Magnesium sulfate (MgSO4) and boron were considered as plant nutrients, while zeolite was used as soil conditioner. The addition of these substances may affect soil NH3 and N2O emissions, by increasing N use efficiency. We conducted an 30 days incubation experiment with ryegrass using fertilizer treatments (12 g N m−2) as follows: urea (U); urea + MgSO4 (UM); urea + MgSO4 + borax (UMB); zeolite + urea + MgSO4 (Z-UM); and zeolite + urea + MgSO4 + borax (Z-UMB). We measured NH3 and N2O emissions and the aboveground N uptake of ryegrass. Cumulative NH3 emissions of UM, UMB, Z-UM and Z-UMB were 10%, 53%, 21% and 58% lower than U, respectively, while their N2O emissions were 32%, 133%, 43% and 72% higher than U, respectively. Aboveground N uptake of UM, UMB, Z-UM and Z-UMB were 9%, 6%, 12% and 13% higher than U, respectively. Overall, we suggest that the addition of MgSO4 and borax were effective in reducing NH3 emissions and potentially increase plant N uptake. However, the risk of higher denitrification and N2O emissions also needs to be considered. This study reveals the considerable effect of MgSO4 and borax in soil N cycles. Future research should evaluate how the application of urea + MgSO4 + borax effects gaseous emissions and crop yield of dicotyledons and in drier soil conditions.

Phosphorus mobilization in unamended and magnesium sulfate-amended soil monoliths under simulated snowmelt flooding

Enhanced release of phosphorus (P) from soils with snowmelt flooding poses a threat of eutrophication to waterbodies in cold climatic regions. Reductions in P losses with various soil amendments has been reported, however effectiveness of MgSO4 has not been studied under snowmelt flooding. This study examined (a) the P release enhancement with flooding in relation to initial soil P status and (b) the effectiveness of MgSO4 at two rates in reducing P release to floodwater under simulated snowmelt flooding. Intact soil monoliths were collected from eight agricultural fields from Southern Manitoba, Canada. Unamended and MgSO4 surface-amended monoliths (2.5 and 5.0 Mg ha−1) in triplicates were pre-incubated for 7 days, then flooded and incubated (4 °C) for 56 days. Pore water and floodwater samples collected at 7-day intervals were analyzed for dissolved reactive P (DRP), pH, Ca, Mg, Fe and Mn. Redox potential (Eh) was measured on each day of sampling. Representative soil samples collected from each field were analyzed for Olsen and Mehlich 3-P. Simulated snowmelt flooding enhanced the mobility of soil P with approximately 1.2–1.6 -fold increase in pore water DRP concentration from 0 to 21 days after flooding. Mehlich-3 P content showed a strong relationship with the pore water DRP concentrations suggesting its potential as a predictor of P loss risk during prolonged flooding. Surface application of MgSO4 reduced the P release to pore water and floodwater. The 2.5 Mg ha−1 rate was more effective than the higher rate with a 21–75% reduction in average pore water DRP, across soils. Soil monoliths amended with MgSO4 maintained a higher Eh, and had greater pore water Ca and Mg concentrations, which may have reduced redox-induced P release and favored re-precipitation of P with Ca and Mg, thus decreasing DRP concentrations in pore water and floodwater.

Effect of magnesium sulfate in oxidized lipid bilayers properties by using molecular dynamics

Magnesium sulfate (MgSO4) has been used as a protector agent for many diseases related to oxidative stress. The effect of MgSO4 on the oxidized lipid bilayer has not yet been studied using molecular dynamics calculations. In this work, the effects of oxidation were evaluated by using a POPC membrane model at different concentrations of its aldehyde (-CHO) and hydroperoxide (-OOH) derivatives with and without MgSO4. Several quantitative and qualitative properties were evaluated, such as membrane thickness, area per lipid, area compressibility modulus, snapshots after simulation finish, density distributions, time evolutions of oxidized group positions, and radial distributions of oxidized group concerning Mg. Results indicate that in the absence of MgSO4 the mobility of oxidized groups, particularly –CHO, toward the surface interface is high. At a low oxidation level of the bilayer there is an increase in the compressibility modulus as compared to the unoxidized bilayer. MgSO4, at a low oxidation level, tends to lessen the oxidation effects by lowering the dispersion in the distribution of oxidized species toward the membrane surface and the water region. However, MgSO4 does not change the trends of decreasing membrane thickness and area compressibility modulus and increasing area per lipid upon oxidation. In this regard, MgSO4 diminishes the electrostatic long-distance attractive interactions between the oxidized groups and the charged headgroups of the interface, owing to the Mg+2 and SO4-2 screening effects and an electrostatic stabilization of the headgroups, preventing the pore formation, which is well-known to occur in oxidized membranes.

Effect of Neuroprotective Magnesium Sulfate Treatment on Brain Transcription Response to Hypoxia Ischemia in Neonate Mice.

MgSO4 is widely used in the prevention of preterm neurological disabilities but its modes of action remain poorly established. We used a co-hybridization approach using the transcriptome in 5-day old mice treated with a single dose of MgSO4 (600 mg/kg), and/or exposed to hypoxia-ischemia (HI). The transcription of hundreds of genes was altered in all the groups. MgSO4 mainly produced repressions culminating 6 h after injection. Bio-statistical analysis revealed the repression of synaptogenesis and axonal development. The putative targets of MgSO4 were Mnk1 and Frm1. A behavioral study of adults did not detect lasting effects of neonatal MgSO4 and precluded NMDA-receptor-mediated side effects. The effects of MgSO4 plus HI exceeded the sum of the effects of separate treatments. MgSO4 prior to HI reduced inflammation and the innate immune response probably as a result of cytokine inhibition (Ccl2, Ifng, interleukins). Conversely, MgSO4 had little effect on HI-induced transcription by RNA-polymerase II. De novo MgSO4-HI affected mitochondrial function through the repression of genes of oxidative phosphorylation and many NAD-dehydrogenases. It also likely reduced protein translation by the repression of many ribosomal proteins, essentially located in synapses. All these effects appeared under the putative regulatory MgSO4 induction of the mTORC2 Rictor coding gene. Lasting effects through Sirt1 and Frm1 could account for this epigenetic footprint.

Vasoactivity of magnesium sulfate in chicken ductus arteriosus.

Prenatal treatment with magnesium sulfate (MgSO4) has neuroprotective effects in very preterm infants but its use has been associated with an increased rate of patent ductus arteriosus (DA). MgSO4 is a vasodilator and thus may exert a direct relaxant effect in the DA. We aimed to investigate the vasoactive effects of MgSO4 in the DA using the chicken embryo as experimental model. DA rings from 15-d (E15), 17-d (E17) and 19-d (E19) chicken embryos (total incubation: 21-d) were mounted in a wire myograph for isometric tension recordings. Exposure of DA rings to 21% O2 induced a tonic contraction which was relaxed by MgSO4 (2.4 - 7.2 mmol L-1) in a concentration-dependent manner (mean maximal relaxation E19: 51.4%, SE 6.3; EC50: 3.5 mmol L-1, SE 0.7). The relaxation evoked by MgSO4 was not significantly different between E15, E17 and E19 DA and was not affected by removal of the endothelium or by the presence of the nitric oxide synthase inhibitor L-NAME, the soluble guanylate cyclase inhibitor ODQ, or the cyclooxygenase inhibitor indomethacin. In contrast, when the DA rings were incubated in Ca2+-free solution, or in the presence of inhibitors of L-type Ca2+ channels (nifedipine), or large-conductance Ca2+-activated K+ (BKCa) channels (iberiotoxin), MgSO4-induced relaxation was impaired. Preincubation of the DA rings with MgSO4 concentrations ranging from 0 to 6.0 mmol L-1 did not significantly affect O2-induced contraction that was only impaired by a concentration of 7.2 mmol L-1. In conclusion, MgSO4 induced endothelium-independent relaxation of chicken DA and this relaxation appeared to be mediated through stimulation of BKCa channels and blockade of transmembrane flux of extracellular Ca2+. However, O2-induced DA contraction was only impaired by suprapharmacological concentrations of MgSO4 (> 6.0 mmol L-1). Therefore, our data suggest that the higher incidence of patent DA in preterm infants exposed to MgSO4 is unlikely to be due to a direct pharmacological effect of the drug on the DA.

Magnesium sulfate prophylaxis attenuates the postpartum effects of preeclampsia by promoting M2 macrophage polarization.

Preeclampsia is a complex disorder that is characterized by new onset hypertension and proteinuria at or after 20 weeks of gestation. Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. MgSO4 is commonly used to treat severe preeclampsia, but its mechanism of action is poorly understood, and investigations into the effects of MgSO4 during the postpartum period are lacking. In this study, timed-pregnant Sprague-Dawley rats received low-dose lipopolysaccharide (LPS) on gestational day 14 to induce preeclampsia. Maternal and fetal outcomes and the macrophage profile 1 week after delivery were explored. On postpartum day (PD) 7, the maternal systolic blood pressure and urinary protein level were significantly increased, the number of M1 macrophages was increased and the number of M2 macrophages was decreased in the maternal kidney and brain; the median duration of gestation, the number of live fetuses, and the fetal weight/placenta weight ratio were significantly decreased; and the percentage of growth-restricted pups and fetal mortality were significantly increased in preeclampsia rats compared to normal pregnant control rats. Prophylactic MgSO4 decreased blood pressure at PD7, improved pregnancy outcomes, and promoted the polarization of M2 macrophages in the kidney and of M2 microglia in the brain of preeclampsia rats. These findings confirm that the pathophysiology of preeclampsia involves the dysregulation of the inflammatory response and the activation of M1 macrophages in several target organs during pregnancy. MgSO4 prophylaxis attenuates the postpartum effects of preeclampsia by promoting M2 macrophage polarization in the maternal kidney and brain.

Effectiveness of Nebulized Magnesium Sulphate as an Adjuvant Therapy (With Salbutamol) in the Management of Acute Asthma

Background: Although the treatment of acute asthma in the emergency department varies, the administration of magnesium sulfate (MgSO4) is usually recommended adjacent to corticosteroids and bronchodilators. This study aims to ascertain the influence of inhaled MgSO4 as complement treatment with salbutamol regarding treatment of urgent asthma exacerbations. Methods: A single-blind randomized control study was carried out, from 1st January 2017 to 30th June 2017, involving asthmatic patients presenting to Ziauddin Hospital and Jinnah Hospital in Karachi, with severe acute asthma exacerbations. The Sealed Envelope calculator was used to calculate a sample size of 84 patients, and data was collected through non-probability consecutive sampling. Both batches were administered salbutamol and ipratropium, with Batch A patients also receiving nebulization with MgSO4. Dyspnea, respiratory rate, pulse, peak expiratory flow rate, and oxygen saturation were recorded for each participant. An independent sample t-test was used to assess the effectiveness of MgSO4, as a significant means of improving asthma treatment, with a p<0.05 interpreted as significant. Results: A sum of 115 patients was included in the research, out of which 63.5% had a family history of asthma. Treatment with MgSO4 was seen as significant (p<0.01). MgSO4 administration showed significant improvement in mean pulse rate (p = 0.001), peak expiratory flow rate (p = 0.004) and mean respiratory rate (p = 0.003), as compared to treatment with salbutamol only. Conclusion: Treatment outcomes between the two groups differed significantly. Intervention with MgSO4 showed significant improvement in pulse rate, respiratory rate, dyspnea, and peak flow, without any observed side effects.

Efficacy of adding magnesium sulfate to bupivacaine for ilioinguinal and iliohypogastric nerve block in acute postherniorrhaphy pain

Background Regional block of ilioinguinal and iliohypogastric (IIIH) nerves has been applied to provide postoperative analgesia after inguinal hernia repair. Magnesium sulfate (MgSo4) blocks N-methyl-d-aspartate receptors, and that is why, it was used as an adjuvant to the local anesthetic (LA) in different anesthetic approaches. Although the prolongation in postoperative duration resulting from the addition of MgSO4 to LA was significant in some literature studies, it was insignificant in others. Objective This study was designed to investigate the adjunctive effect of MgSo4 when added to bupivacaine for IIIH blockade on the postoperative analgesic duration as a primary outcome and on the verbal rating scale (VRS) scores, analgesic consumption, and hemodynamics as secondary outcomes. Patients and methods Patients were divided into two groups of 45 patients each by means of coded envelopes according to the LA used for IIIH blockade. In the first group (control group), patients received 10 ml 0.5% isobaric bupivacaine plus 1 ml normal saline for IIIH blockade, whereas in the second group (MgSo4 group), 10 ml 0.5% isobaric bupivacaine and 1 ml of MgSo4 10% were prepared. All the patients received intrathecal 3 ml 0.5% hyperbaric bupivacaine, and then, IIIH blockade was performed under ultrasound guidance according to the group. Postoperatively, VRS scores, analgesic duration, and any complication were recorded. Results There was a significantly prolonged analgesic duration in MgSo4 group when compared with the control group. However, the consumed analgesic in the first postoperative day and the pain score were insignificantly lower in MgSo4 group. Conclusion The addition of MgSO4 to bupivacaine for IIIH nerve block prolonged the postoperative analgesic duration after inguinal hernia repair without significant effect on the analgesic consumption or VRS scores.

Magnesium sulfate inhibits binding of lipopolysaccharide to THP-1 cells by reducing expression of cluster of differentiation 14.

We investigated effects of magnesium sulfate (MgSO4) on modulating lipopolysaccharide (LPS)-macrophage binding and cluster of differentiation 14 (CD14) expression. Flow cytometry data revealed that the mean levels of LPS-macrophage binding and membrane-bound CD14 expression (mCD14) in differentiated THP-1 cells (a human monocytic cell line) treated with LPS plus MgSO4 (the LPS + M group) decreased by 28.2% and 25.3% compared with those THP-1 cells treated with LPS only (the LPS group) (P < 0.001 and P = 0.037), indicating that MgSO4 significantly inhibits LPS-macrophage binding and mCD14 expression. Notably, these effects of MgSO4 were counteracted by L-type calcium channel activation. Moreover, the mean level of soluble CD14 (sCD14; proteolytic cleavage product of CD14) in the LPS + M group was 25.6% higher than in the LPS group (P < 0.001), indicating that MgSO4 significantly enhances CD14 proteolytic cleavage. Of note, serine protease inhibition mitigated effects of MgSO4 on both decreasing mCD14 and increasing sCD14. In conclusion, MgSO4 inhibits LPS-macrophage binding through reducing CD14 expression. The mechanisms may involve antagonizing L-type calcium channels and activating serine proteases.

Antenatal Magnesium Sulfate Exposure and Ponderal Index in Preterm Infants.

Antenatal magnesium sulfate (MgSO4) is known to affect the central nervous system of preterm infants, and there is biologic rationale for influence on other phenotypes. This study investigated the effect of MgSO4 exposure on the trajectory of ponderal index (PI, kg/m3) from birth to 2 years of age. A secondary analysis of a U.S. randomized controlled trial investigating MgSO4 versus placebo administration among women at high risk for preterm delivery was performed. Multivariable logistic regression was used to assess the relationship between PI from birth to 2 years of age and exposure to MgSO4 versus placebo. There was a larger decrement in PI from birth to 2 years of age in infants exposed to MgSO4 compared with placebo (p = 0.032). There was a statistically significant one-way interaction between newborn sex and treatment group (p = 0.019). Change in PI in males exhibited a greater decrement in those exposed to MgSO4 versus placebo (p = 0.227), whereas female infants exposed to MgSO4 had a smaller decrement (p = 0.04). MgSO4 exposure in preterm infants is associated with a larger decrease in PI from birth to 2 years of age. In addition, the direction of effect of MgSO4 on the change in PI over the first 2 years of life is different by sex.

Effects of magnesium sulfate infusion on clinical signs and lung function of horses with severe asthma.

OBJECTIVE To evaluate whether MgSO4 solution administered IV would improve the clinical signs and lung function of horses with severe asthma and potentiate the effects of salbutamol inhalation in those horses. ANIMALS 6 adult horses with severe asthma. PROCEDURES Asthmatic horses were used in 3 crossover design experiments (6 treatments/horse). Clinical scores for nasal flaring and the abdominal component associated with breathing and lung function were determined before and after administration of salbutamol (800 μg, by inhalation), MgSO4 solution (2.2 mg/kg/min, IV, over 20 minutes), and combined MgSO4-salbutamol treatment. The data were collected during experimental procedures to assess salbutamol inhalation versus mock inhalation, MgSO4 infusion versus infusion of saline (NaCl) solution (adjusted to the same osmolarity as the MgSO4 solution), and the combined MgSO4-salbutamol treatment versus salbutamol inhalation alone. RESULTS Infusion of MgSO4 significantly improved clinical scores when administered alone or in combination with salbutamol inhalation. With the combination treatment, lung function improved, albeit not significantly. Tidal volume also increased following combined MgSO4-salbutamol treatment. Salbutamol alone significantly improved lung function, whereas saline solution administration and a mock inhalation procedure had no effect on the studied variables. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that MgSO4 infusion alone or in combination with salbutamol inhalation improved the clinical signs of severely asthmatic horses. The effects of MgSO4 were not associated with significant lung function improvement, which suggested that the changes observed were attributable to alterations in the horses' breathing patterns. Infusion of MgSO4 solution at the studied dose offers little advantage over currently used medications for the treatment of severe equine asthma.

The effect of magnesium sulfate concentration on the effective concentration of rocuronium, and sugammadex-mediated reversal, in isolated left phrenic nerve hemi-diaphragm preparations from the rat.

BackgroundPerioperative magnesium sulfate (MgSO4) is used for analgesic, anti-arrhythmic, and obstetric purposes. The effects of MgSO4 on the neuromuscular blockade (NMB) induced by rocuronium, and the sugammadex reversal thereof, have not been clearly quantified. We investigated the effect of various MgSO4 concentrations on the NMB by rocuronium, and sugammadex reversal, in isolated left phrenic nerve hemi-diaphragm (PNHD) preparations from the rat.MethodsRat PNHD preparations were randomly allocated to one of four groups varying in terms of MgSO4 concentration (1, 2, 3, and 4 mM, each n = 10, in Krebs solution). The train-of-four (TOF) and twitch height responses were recorded mechanomyographically. The preparations were treated with incrementally increasing doses of rocuronium and each group’s effective concentration (EC)50, EC90, and EC95 of rocuronium were calculated via nonlinear regression. Then, sugammadex was administered in doses equimolar to rocuronium. The recovery index, time to T1 height > 95% of control, and the time to a TOF ratio > 0.9 after sugammadex administration were measured.ResultsThe EC50, EC90, and EC95 of rocuronium fell significantly as the magnesium level increased. The EC50, EC90, and EC95 of rocuronium did not differ between the 3 and 4 mM groups. The recovery index, time to T1 height > 95% of control, and time to a TOF ratio > 0.9 after sugammadex administration did not differ among the four groups.ConclusionsIncreases in the magnesium concentration in rat PNHD preparations proportionally enhanced the NMB induced by rocuronium but did not affect reversal by equimolar amounts of sugammadex.

Magnesium sulfate prevents the development of forced swim induced hyperalgesia in rats

The present study evaluated the effect of magnesium sulfate (MgSO 4) on forced swim-induced thermal hyperalgesia in male Sprague-Dawley rats. Two schemes of MgSO 4 administration were used: a preemptive scheme (100 mg/kg i.p. before each forced swim) and a therapeutic scheme (a single dose of 100 mg/kg, 24 hours after the final forced swim); pharmacological controls received normal saline. Thermal nociception was determined using the hot plate test, and lumbar spinal levels of nitric oxide (NO) metabolites were measured. Thermal hyperalgesia was present in forced swim animals treated with saline before each forced swim, but absent in forced swim animals preemptively treated with MgSO 4. We could not determine an anti-hyperalgesic effect of the therapeutic scheme since MgSO 4 tended to produce analgesia when administered one hour before the hot plate test, probably due to an acute stress response caused by the injection. On the other hand, non-stressed animals preemptively treated with MgSO 4 displayed significantly higher levels of NO metabolites than forced swim animals preemptively treated with MgSO 4 or saline and non-stressed animals preemptively treated with saline. The results suggest that MgSO 4 can prevent the development of persistent pain states, but is unable to revert already established ones, a potential feature in patients suffering from anxiety, depression and chronic stress exposure; likewise, they indicate that the effect of MgSO 4 on nociception is independent of an induction of NO synthesis. Corresponding author: Ricardo Cardenas-Fernandez. Seccion de Neurofarmacologia y Neurociencias, Instituto

Effects of MgSO4 on inhibiting Nod-like receptor protein 3 inflammasome involve decreasing intracellular calcium

BackgroundNod-like receptor protein 3 (NLRP3) inflammasome is a multiprotein complex composed of NLRP3, caspase-1, and apoptosis-associated speck-like protein containing a caspase recruitment domain. Activation of NLRP3 inflammasome leads to interleukin-1β (IL-1β) upregulation and pyroptosis, a proinflammatory cell death characterized by increased cell size. Of note, calcium signaling is crucial for NLRP3 inflammasome activation. This study elucidated the effects of magnesium sulfate (MgSO4), a potent calcium antagonist, on modulating NLRP3 inflammasome. Materials and methodsTHP-1 cells, the human monocytic leukemia cell line, were treated with lipopolysaccharide (LPS, 1 μg/ml) plus nigericin (5 μM) (the LPS + Nig group) and LPS plus nigericin plus MgSO4 (20 mM) [the LPS + Nig + M(20)] to facilitate investigations. Levels of IL-1β, pyroptosis, and NLRP3 inflammasome induction as well as intracellular calcium were assayed. ResultsIL-1β concentration of the LPS + Nig + M(20) group was significantly lower than the LPS + Nig group (P = 0.001). Cell size of the LPS + Nig + M(20) group was significantly smaller than the LPS + Nig group (P < 0.001). Level of pyroptotic cell death of the LPS + Nig + M(20) group was significantly lower than the LPS + Nig group (P = 0.004). NLRP3 mRNA and protein concentrations of the LPS + Nig + M(20) group were also significantly lower than the LPS + Nig group (P = 0.021 and P < 0.001). Similarly, apoptosis-associated speck-like protein containing a caspase recruitment domain speck formation ratio and caspase-1 concentration of the LPS + Nig + M(20) group were significantly lower than the LPS + Nig group (both P < 0.001). The change in intracellular calcium level of the LPS + Nig + M(20) group was significantly smaller than the LPS + Nig group (P = 0.001). ConclusionsMgSO4 inhibits NLRP3 inflammasome, IL-1β upregulation, and pyroptosis. The mechanism is consistent with decreased intracellular calcium levels.