Neuropharmacological actions of some binuclear lanthanide(III) complexes.
Binuclear lanthanide(III) compounds are of great interest because of the potential of their mutual Ln(3+)-Ln(3+) electronic couplings to produce unusually sharp images in magnetic resonance and fluorescence imaging of biological tissue. The toxicity and neuropharmacological properties of the water soluble and stable neutral binuclear complex [La(api)](2) were compared with those of binuclear complexes with lower water stability, and the components used in their syntheses. The order of the 24-h LD(50) (mg/kg body wt.) of the compounds in mice was: salicylaldehyde (2.24)<H(3)api (32.3)<[La(2) L(1) (NO(3))(4)].H(2)O (35.1)<triethylenetetramine (38.5)<La(2) L(2)(NO(3))](2) (43.4)<La(NO(3))(3).5H(2)O=[GdL(3) (NO(3))](2) (45.7)<La(2)L(4) (NO(3))(4).CH(3)OH (49.6)<[La (api)](2) (>160). These compounds induced convulsions, urination and defecation in mice. Due to the relatively very low toxicity of [La(api)](2), its mode of action was explored. Its proconvulsant action may possibly involve an interaction of undissociated complex with muscarinic receptors, and is reversed by atropine.
Williams
L A
LA
Department of Chemistry, University of the West Indies, Mona Campus, Kingston 7, Jamaica.
Howell
R C
RC
Young
R
R
Kahwa
I A
IA
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003292:Convulsants / Q000633:toxicity*; D003672:Defecation / Q000187:drug effects; D003975:Diazepam / Q000494:pharmacology; D007928:Lethal Dose 50; D008674:Metals, Rare Earth / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D010277:Parasympathomimetics / Q000494:pharmacology; D010424:Pentobarbital / Q000494:pharmacology; D012640:Seizures / Q000139:chemically induced; D014554:Urination / Q000187:drug effects
D003292:Convulsants; D008674:Metals, Rare Earth; D010277:Parasympathomimetics; D001285:Atropine; D010424:Pentobarbital; D003975:Diazepam