A novel side-bridged hybrid phosphonate/acetate pendant cyclam: synthesis, characterization, and 64Cu small animal PET imaging.

Copper-64 (t(1/2)=12.7h; beta(+): 0.653 MeV, 17.

Validation of a novel CHX-A'' derivative suitable for peptide conjugation: small animal PET/CT imaging using yttrium-86-CHX-A''-octreotide.

A versatile bifunctional chelating reagent based on a preorganized cyclohexyl derivative of DTPA (CHX-A'') has been developed for the convenient N-terminal labeling of peptides with metal ion radionuclides of Bi(III), In(III), Lu(III), or Y(III). This was achieved via the synthesis of a mono-N-hydroxysuccinimidyl penta-tert-butyl ester derivative of CHX-A'' (trans-cyclohexyldiethylenetriaminepenta-acetic acid) featuring a glutaric acid spacer. Commercially obtained octreotide was modified at its N-terminus by this reagent in the solution phase, and its subsequent radiolabeling with (111)In (T(1/2) = 2.

Chronic lithium treatment antagonizes glutamate-induced decrease of phosphorylated CREB in neurons via reducing protein phosphatase 1 and increasing MEK activities.

The cyclic AMP response element binding protein (CREB) has major roles in mediating adaptive responses at glutamatergic synapses and in the neuroprotective effects of neurotrophins. CREB has been implicated as a potential mediator of antidepressant actions. In vitro, chronic lithium treatment has been shown to promote neuronal cell survival.