Effects of mercury compounds on the spontaneous and potassium-evoked release of [3H]dopamine from mouse striatal slices.
The effects of mercury compounds on the spontaneous and potassium-evoked release of [3H]dopamine from mouse striatal slices have been examined. All mercury compounds examined produced concentration-dependent increases in the spontaneous release of [3H]dopamine, with an order of potency of methylmercury greater than mercuric (Hg2+) mercury greater than p-choloromercuribenzene sulfonic acid. Methylmercury had no effect on the 25 mM potassium evoked release of [3H]dopamine in the presence of 1.3 mM calcium. However, in calcium-free conditions, methylmercury significantly increased the potassium-evoked release of [3H]dopamine. Mercuric mercury significantly reduced the 25 mM potassium evoked release of [3H]dopamine in the presence of 1.3 mM calcium, and this response was not reversible with brief washing of the tissue. In calcium-free conditions, mercuric mercury significantly elevated the evoked release of [3H]dopamine, similar to the result obtained with methylmercury. It is suggested that mercury compounds alter dopaminergic synaptic function, possibly by disrupting calcium homeostasis or calcium-dependent processes, and that methylmercury and mercuric mercury can have differential effects to alter dopaminergic neurotransmission.
D002731:4-Chloromercuribenzenesulfonate / Q000633:toxicity; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects; D008297:Male; D008627:Mercuric Chloride / Q000633:toxicity; D008628:Mercury / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000633:toxicity; D051379:Mice; D011188:Potassium / Q000494:pharmacology
D007473:Ion Channels; D008767:Methylmercury Compounds; D008627:Mercuric Chloride; D002731:4-Chloromercuribenzenesulfonate; D008628:Mercury; D011188:Potassium; C004925:methylmercuric chloride; D002118:Calcium; D004298:Dopamine