Actions of manganese ions in contraction of smooth muscle

Nasu, Tetsuyuki

doi:10.1016/0306-3623(94)00273-p

Cited by 9 publications

(5 citation statements)

References 56 publications

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“…Manganese, malvolio and honey bee foraging a cell because, in Drosophila, mutations of the mvl locus are not lethal and behavioral defects are rescued by manganese treatment (Orgad et al, 1998;Rodrigues et al, 1995). Also, some evidence suggests that manganese ions can also permeate the cell membrane via voltage-gated calcium channels (Nasu, 1995). However, the observation that zinc, a known antagonist of mvl (Orgad et al, 1998;Supek et al, 1996), attenuated the behavioral effect of manganese suggests that manganese transport via mvl is a primary route into brain cells, either neurons, glia or both.…”

Section: Discussionmentioning

confidence: 99%

Phenotypic deconstruction reveals involvement of manganese transportermalvolioin honey bee division of labor

Ben‐Shahar

Dudek

Robinson

2004

Journal of Experimental Biology

109

113

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Molecular analysis of a complex behavioral phenotype is facilitated by dissecting it into simpler behavioral components. Using this approach, we present evidence implicating increased manganese transport by the malvolio (mvl) gene into brain cells as one factor that influences age-related division of labor in honey bee colonies. We studied mvl because manganese affects sucrose responsiveness in Drosophila melanogaster, and sucrose responsiveness is related to division of labor in honey bee colonies. Honey bee foragers are more responsive to sucrose in the laboratory than are younger nurse bees, and pollen foragers are more responsive to sucrose than nectar foragers. Levels of mvl mRNA in the brain and manganese in the head were higher in pollen foragers compared with nurses, with nectar foragers intermediate. Manganese treatment increased honey bee sucrose responsiveness and caused precocious foraging. Manganese levels showed a similar pattern to mvl mRNA but manganese treatment did not increase pollen foraging. These results suggest that, while there are molecular pathways common to sucrose responsiveness and division of labor, linkages between a complex behavior and some of its simpler behavioral components are not obligatory. Together with previous findings, these results support the idea that some feeding-related genes in Drosophila have been used in social evolution to regulate division of labor.

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Section: Discussionmentioning

confidence: 99%

Phenotypic deconstruction reveals involvement of manganese transportermalvolioin honey bee division of labor

Ben‐Shahar

Dudek

Robinson

2004

Journal of Experimental Biology

109

113

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“…Mn 2þ interacts with smooth muscle at multiple levels and exposing vascular territories to Mn 2þ leads to complicated responses including vasodilation or vasoconstriction. 71 The direction and magnitude of response depends upon Mn 2þ concentration, duration of exposure and time elapse afterward and the properties of different vascular territories. 71 The most important aspect from the standpoint of Mn-based cardiac imaging is that Mn 2þ causes a hypotensive response, 6 and the hypotensive response occurs at lower Mn 2þ concentration than negative inotropic effects.…”

Section: Physiological Effect Of Mn 2þ Exposurementioning

confidence: 99%

Applications of manganese‐enhanced magnetic resonance imaging (MEMRI) to imaging of the heart

Wendland

2004

NMR in Biomedicine

101

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The use of manganese-based MRI contrast materials, either manganese salts or chelates, has spanned the entire timeframe of cardiac MRI. However interest in Mn compounds for cardiac MRI has been sporadic because of concerns over cardiotoxicity associated with significant concentration of free Mn 2þ and notable success of gadolinium chelates in cardiac application. Initial strategies to overcome cardiotoxicity included chelation of Mn 2þ to reduce the concentration of the free ion in vivo, and addition of Ca 2þ in combination with Mn 2þ to competitively reduce binding of Mn 2þ to Ca 2þ channels in the heart. Both approaches met with mixed success, but were subsequently discontinued in favor of gadolinium-based approaches. However Mn 2þ -based media potentially offer unique advantages for characterizing heart pathology over conventional Gd-based contrast media because Mn 2þ is taken up by heart cells and retained for hours. Cellular uptake occurs through calcium channels so contrast on delayed images may be interpreted according to regional or global functional status. Since Mn 2þ is retained in the heart, Mn-based media can be administered outside the magnet and the contrast pattern measured hours later to provide assessment of uptake. A key issue is whether sufficient accumulation of Mn 2þ in heart cells for imaging can occur without cardiotoxicity, and findings to date indicate this is possible. This review examines the current status of Mn 2þ -enhanced MRI of heart with particular focus on the hypothesis that Mn 2þ uptake can be interpreted in terms of heart function. Copyright # 2004 John Wiley & Sons, Ltd.KEYWORDS: magnetic resonance imaging; manganese; contrast media; myocardial ischemia; myocardial function; myocardial perfusion OVERVIEW Manganese (II) was the first MRI contrast agent. Lauterbur et al. 1 found that administration of inorganic salts of divalent Mn increased R 1 , particularly in liver, kidney, and heart. 2 In the heart increased R 1 of tissue was proportional to quantity of Mn 2þ accumulated within it, 1,2 and both quantity of Mn 2þ and R 1 enhancement were reduced in myocardium distal to an occluded artery. Mn 2þ was considered a promising contrast material for use in cardiac MRI because of its potent R 1 enhancement, its fairly rapid uptake by heart cells and its only moderate toxicity. Manganese is an essential trace mineral with a stable physiologic pool and a physiological system for handling it. Most notably, manganese is essential to aerobic organisms because Mn 2þ is required by mitochondrial superoxide dismutase (SOD). 3 The important issue was the moderate toxicity. In addition to manganese poisoning, which caused parkinsonism-like symptoms after chronic overexposure, Mn 2þ was known to block normal calcium fluxes in the heart, which caused a prominent cardiotoxicity. A dose of 0.1 mmol/kg administered by rapid intravenous injection kills rats, 2 stopping the heart within a few minutes. After a few early encouraging MRI studies with low doses of MnCl 2 , 2,4,5 Wolf and Ba...

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“…A recent study also revealed that mice receiving 0.4 mmol MnCl 2 /kg intraperitoneally had reduced intestinal smooth muscle contractions due to Ca 2+ uptake inhibition, which could be overcome by high extracellular Ca 2+ concentrations . It has also been reported that micromolar concentrations of Mn 2+ can cause a transient contractile response through the release of acetylcholine . Mn 2+ has also been shown to enter cells via voltage‐operated L‐type Ca 2+ channels and directly induce contractions at millimolar concentrations in a Ca 2+ ‐free, high‐K + medium .…”

Section: Discussionmentioning

confidence: 99%

Monitoring dynamic alterations in calcium homeostasis by T₁‐mapping manganese‐enhanced MRI (MEMRI) in the early stage of small intestinal ischemia–reperfusion injury

et al. 2015

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Manganese-enhanced MRI studies have proven to be useful in monitoring physiological activities associated with calcium ions (Ca(2+)) due to the paramagnetic property of the manganese ion (Mn(2+)), which makes it an excellent probe of Ca(2+) . In this study, we developed a method in which a Mn(2+)-enhanced T1 -map MRI could enable the monitoring of Ca(2+) influx during the early stages of intestinal ischemia-reperfusion (I/R) injury. The Mn(2+) infusion protocol was optimized by obtaining dose-dependent and time-course wash-out curves using a Mn(2+)-enhanced T1-map MRI of rabbit abdomens following an intravenous infusion of 50 mmol/l MnCl2 (5-10 nmol/g body weight (BW)). In the rabbit model of intestinal I/R injury, T1 values were derived from the T1 maps in the intestinal wall region and revealed a relationship between the dose of the infused MnCl2 and the intestinal wall relaxation time. Significant Mn(2+) clearance was also observed over time in control animals after the infusion of Mn(2+) at a dose of 10 nmol/g BW. This technique was also shown to be sensitive enough to monitor variations in calcium ion homeostasis in vivo after small intestinal I/R injury. The T1 values of the intestinal I/R group were significantly lower (P < 0.05) than that of the control group at 5, 10, and 15 min after Mn(2+) infusion. Our data suggest that MnCl2 has the potential to be an MRI contrast agent that can be effectively used to monitor changes in intracellular Ca(2+) homeostasis during the early stages of intestinal I/R injury.

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Actions of manganese ions in contraction of smooth muscle

Cited by 9 publications

References 56 publications

Phenotypic deconstruction reveals involvement of manganese transportermalvolioin honey bee division of labor

Phenotypic deconstruction reveals involvement of manganese transportermalvolioin honey bee division of labor

Applications of manganese‐enhanced magnetic resonance imaging (MEMRI) to imaging of the heart

Monitoring dynamic alterations in calcium homeostasis by T₁‐mapping manganese‐enhanced MRI (MEMRI) in the early stage of small intestinal ischemia–reperfusion injury

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Actions of manganese ions in contraction of smooth muscle

Cited by 9 publications

References 56 publications

Phenotypic deconstruction reveals involvement of manganese transportermalvolioin honey bee division of labor

Phenotypic deconstruction reveals involvement of manganese transportermalvolioin honey bee division of labor

Applications of manganese‐enhanced magnetic resonance imaging (MEMRI) to imaging of the heart

Monitoring dynamic alterations in calcium homeostasis by T1‐mapping manganese‐enhanced MRI (MEMRI) in the early stage of small intestinal ischemia–reperfusion injury

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Resources

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Monitoring dynamic alterations in calcium homeostasis by T₁‐mapping manganese‐enhanced MRI (MEMRI) in the early stage of small intestinal ischemia–reperfusion injury