Interaction of mercury compounds with muscarinic receptor subtypes in the rat brain

A. F. Castoldi, S. M. Candura, P. Costa, L. Manzo, L. G. Costa

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

The in vitro effects of mercuric chloride (HgCl2) and methylmercury (CH3HgOH) on the M1 and M2 muscarinic receptor subtypes were investigated in rat brain cortical membranes. HgCl2 and CH3HgOH were almost equipotent in inhibiting the binding of [3H]telenzepine to M1 receptors (IC50s = 2.2 and 3.4 μM, respectively). Conversely, HgCl2 was a thirty-fold more potent inhibitor of [3H]AF-DX 384 binding to M2 sites than CH3HgOH (IC50s = 5 and 149 μM, respectively). In all cases HgCl2 showed steep and monophasic inhibition curves, whereas those of CH3HgOH were biphasic (M1) or shallow (M2). CH3HgOH-induced inhibition of both [3H]telenzepine and [3H]AF-DX 384 binding was of the competitive type, while HgCl2 caused a pronounced reduction of the B(max) value associated with a small change in affinity. CH3HgOH also decreased the affinity of the agonist carbachol tot M1 and M2 receptors, while inorganic mercury had minimal effects on the carbachol dose- response curves. These results indicate that inorganic and organic mercury differ in their interaction with muscarinic receptor subtypes and that M1 receptors may represent a preferential target for their effects.

Original languageEnglish
Pages (from-to)735-742
Number of pages8
JournalNeuroToxicology
Volume17
Issue number3-4
Publication statusPublished - 1996

Fingerprint

Mercury Compounds
Mercuric Chloride
Muscarinic Receptors
Rats
Brain
Muscarinic M1 Receptors
Carbachol
Mercury
Muscarinic M2 Receptors
Competitive Binding
Membranes

Keywords

  • Mercuric Chloride
  • Methylmercury
  • Muscarinic Receptor Subtypes
  • Neurotoxicity

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Neuroscience(all)
  • Toxicology

Cite this

Castoldi, A. F., Candura, S. M., Costa, P., Manzo, L., & Costa, L. G. (1996). Interaction of mercury compounds with muscarinic receptor subtypes in the rat brain. NeuroToxicology, 17(3-4), 735-742.

Interaction of mercury compounds with muscarinic receptor subtypes in the rat brain. / Castoldi, A. F.; Candura, S. M.; Costa, P.; Manzo, L.; Costa, L. G.

In: NeuroToxicology, Vol. 17, No. 3-4, 1996, p. 735-742.

Research output: Contribution to journalArticle

Castoldi, AF, Candura, SM, Costa, P, Manzo, L & Costa, LG 1996, 'Interaction of mercury compounds with muscarinic receptor subtypes in the rat brain', NeuroToxicology, vol. 17, no. 3-4, pp. 735-742.
Castoldi, A. F. ; Candura, S. M. ; Costa, P. ; Manzo, L. ; Costa, L. G. / Interaction of mercury compounds with muscarinic receptor subtypes in the rat brain. In: NeuroToxicology. 1996 ; Vol. 17, No. 3-4. pp. 735-742.
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