Differential effects of methylmercuric chloride and mercuric chloride on the L-glutamate and potassium evoked release of [3H]dopamine from mouse striatal slices

1986 ◽  
Vol 64 (5) ◽  
pp. 656-660 ◽  
Author(s):  
S. J. McKay ◽  
J. N. Reynolds ◽  
W. J. Racz

The effects of CH3HgCl and HgCl2 on the evoked release of 3H from mouse striatal slices prelabelled with [3H]dopamine have been examined. CH3HgCl (10 μM) was observed to increase the L-glutamate-evoked release of [3H]dopamine, while HgCl2 (10 μM) had no effect. In contrast, CH3HgCl at concentrations up to 100 μM had no effect on the 25 mM K+-stimulated release of [3H]dopamine, whereas HgCl2 (100 μM) significantly reduced the 25 mM K+-stimulated release of [3H]dopamine. Thus CH3HgCl and HgCl2 have differential effects on the L-glutamate- and K+-stimulated release of [3H]dopamine from mouse striatal slices, suggesting that these compounds may have different sites and (or) mechanisms of action in altering neurotransmitter release. It is suggested that CH3HgCl may act predominantly at intracellular sites or at the level of the L-glutamate receptor, whereas the major site of action of HgCl2 may be the voltage-operated calcium channel.

2010 ◽  
Vol 38 (6) ◽  
pp. 1424-1431 ◽  
Author(s):  
Antony Galione ◽  
Anthony J. Morgan ◽  
Abdelilah Arredouani ◽  
Lianne C. Davis ◽  
Katja Rietdorf ◽  
...  

Recent studies into the mechanisms of action of the Ca2+-mobilizing messenger NAADP (nicotinic acid–adenine dinucleotide phosphate) have demonstrated that a novel family of intracellular Ca2+-release channels termed TPCs (two-pore channels) are components of the NAADP receptor. TPCs appear to be exclusively localized to the endolysosomal system. These findings confirm previous pharmacological and biochemical studies suggesting that NAADP targets acidic Ca2+ stores rather than the endoplasmic reticulum, the major site of action of the other two principal Ca2+-mobilizing messengers, InsP3 and cADPR (cADP-ribose). Studies of the messenger roles of NAADP and the function of TPCs highlight the novel role of lysosomes and other organelles of the endocytic pathway as messenger-regulated Ca2+ stores which also affects the regulation of the endolysosomal system.


2020 ◽  
Vol 3 (4) ◽  
pp. 558-576
Author(s):  
Seithikurippu R Pandi-Perumal ◽  
Daniel P Cardinali ◽  
Russel J Reiter ◽  
Gregory M Brown

That the pineal gland is a source of melatonin is widely known; however, by comparison, few know of the much larger pool of extrapineal melatonin. That pool is widely distributed in all animals, including those that do not have a pineal gland, e.g., insects.  Extrapineal melatonin is not released into the blood but is used locally to function as an antioxidant, anti-inflammatory agent, etc. A major site of action of peripherally-produced melatonin is the mitochondria where it neutralizes reactive oxygen species (ROS) that are generated during oxidative phosphorylation. Its role also includes major actions as an immune modulator reducing overreactions to foreign agents while simultaneously boosting immune processes. During a pandemic such as coronavirus disease 2019 (COVID-19), caused by the virus SARS-CoV-2, melatonin is capable of suppressing the damage inflicted by the cytokine storm. The implications of melatonin in susceptibility and treatment of COVID-19 disease are discussed. 


2011 ◽  
Vol 52 (6) ◽  
pp. 1200-1210 ◽  
Author(s):  
Mohamad Navab ◽  
Srinivasa T. Reddy ◽  
G. M. Anantharamaiah ◽  
Satoshi Imaizumi ◽  
Greg Hough ◽  
...  

1997 ◽  
Vol 73 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Ikumi Arai ◽  
Takao Shimazoe ◽  
Shigenobu Shibata ◽  
Hirotaka Inoue ◽  
Akiko Yoshimatsu ◽  
...  

1979 ◽  
Vol 27 (9) ◽  
pp. 1283-1284 ◽  
Author(s):  
L I Larsson

Immunocytochemical studies habe shown that many peptides which profoundly affect the endocrine and exocrine functions of the pancreas are localized to neurons. In the cat, such peptidergic nerves appear to innervate ganglia, islets and blood vessels of the pancreas, whereas their contributions to exocrine cells are minor. Our studies suggest that pancreatic ganglia represent one major site of action of the peptides and that, in addition, nerves containing the vasoactive intestinal polypeptide and gastrin/CCK-related peptides profoundly affect pancreatic blood flow and insulin secretion, respectively.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Michael A Gaviño ◽  
Kevin J Ford ◽  
Santiago Archila ◽  
Graeme W Davis

Homeostatic signaling stabilizes synaptic transmission at the neuromuscular junction (NMJ) of Drosophila, mice, and human. It is believed that homeostatic signaling at the NMJ is bi-directional and considerable progress has been made identifying mechanisms underlying the homeostatic potentiation of neurotransmitter release. However, very little is understood mechanistically about the opposing process, homeostatic depression, and how bi-directional plasticity is achieved. Here, we show that homeostatic potentiation and depression can be simultaneously induced, demonstrating true bi-directional plasticity. Next, we show that mutations that block homeostatic potentiation do not alter homeostatic depression, demonstrating that these are genetically separable processes. Finally, we show that homeostatic depression is achieved by decreased presynaptic calcium channel abundance and calcium influx, changes that are independent of the presynaptic action potential waveform. Thus, we identify a novel mechanism of homeostatic synaptic plasticity and propose a model that can account for the observed bi-directional, homeostatic control of presynaptic neurotransmitter release.


Nature ◽  
1989 ◽  
Vol 340 (6235) ◽  
pp. 639-642 ◽  
Author(s):  
Diane Lipscombe ◽  
Sathapana Kongsamut ◽  
Richard W. Tsien

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