Presynaptic and postsynaptic effects of mercuric ions on guinea-pig ileum longitudinal muscle strip preparation
| Autor: | Susan Korossy, Zoltan Abram |
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| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Cations Divalent Guinea Pigs Tetrodotoxin Biochemistry Sodium Channels Guinea pig Cellular and Molecular Neuroscience chemistry.chemical_compound Postsynaptic potential Ileum Internal medicine medicine Animals Neurotransmitter Chemistry Muscle Smooth General Medicine Smooth muscle contraction Cobalt Mercury Acetylcholine Electric Stimulation Endocrinology Synapses Biophysics Liberation Cholinergic Calcium Female Calcium Channels medicine.symptom Muscle contraction medicine.drug Muscle Contraction |
| Zdroj: | Neurochemical research. 19(12) |
| ISSN: | 0364-3190 |
| Popis: | The toxic effect of mercuric ions on intestinal cholinergic neurotransmission was investigated in vitro. Hg2+ inhibited the evoked release and enhanced the resting release of ACh. Smooth muscle contraction was irreversibly inhibited by Hg2+ in a concentration-dependent manner, and Na2EDTA did not antagonize this effect. We also investigated if Hg2+ enters the nerve terminal through Ca(2+)-channels, or Na(+)-channels, or both. The effects of mercuric ions obtained in our study were completely abolished by the combined administration of TTX and Co2+. It is suggested that the site of the action of mercuric ions is intracellular. We concluded that Hg2+ may interfere with cholinergic transmission by blocking [Ca2+]o-dependent release of ACh and by enhancing [Ca2+]o-independent resting release of ACh. The effect of Hg2+ was not only presynaptic since it also inhibited the effect of ACh on smooth muscle. |
| Databáze: | OpenAIRE |
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