Anti-Phosphotyrosine polyclonal antibody

Olfactory bulbectomy (OBX) in rodents induces neurochemical and behavioral changes similar to those observed in individuals with depressive disorders. Our previous study suggested that OBX alters dopaminergic function in the striatum of mice; however, the effects on dopaminergic function in the hypothalamus is unknown. Therefore, in this study we examined dopaminergic system changes in the hypothalamus after OBX. Mice were administrated either the nonselective dopamine (DA) agonist apomorphine or the selective D-2 agonist quinelorane, or pretreated with the selective D-1 antagonist SCH23390 in combination with the selective D-2 antagonist sulpiride or D-3 antagonist SB277011A. Body temperature, which is regulated by the hypothalamic dopaminergic system, was monitored to evaluate changes in the dopaminergic system of the hypothalamus. DA D-2 receptor (D2DR), tyrosine hydroxylase (TH), and phosphorylated (p)- DA- and cAMP-regulated phosphoprotein-32 (DARPP-32) levels in the hypothalamus were evaluated by western blotting. OBX mice exhibited significantly enhanced apomorphine-induced or quinelorane-induced hypothermia. The apomorphine-induced hypothermic response was reversed by the administration of sulpiride, but not SCH23390 or SB277011A. Moreover, TH and p-DARPP-32 levels were reduced and D2DR increased in the hypothalamus of OBX mice. These findings revealed that the OBX mice display enhanced DA receptor responsiveness associated with the hypothalamus, which may relate to some of the behavioral and neurochemical alterations reported in this animal model. Identification of changes in the hypothalamic dopaminergic system of OBX mice may provide useful information for the development of novel antidepressant treatments.

In this work, L-cysteine-capped CdTe quantum dots (L-Cys/CdTe QDs) were used as novel chiral probes for in enantioselective recognition and quantitative determination of tyrosine (Tyr) enantiomers using both fluorescence and circular dichroism (CD) spectroscopies. Different quenching percentages in fluorescence of L-Cys/CdTe QDs in the presence of similar concentrations of Tyr enantiomers were clearly observed. Quantum mechanical (QM) calculations were also used to confirm such different interactions of L- and D-Tyr enantiomers with L-Cys/CdTe QDs. However, the CD spectroscopy exhibited higher capability and sensitivity, compared to fluorescence spectroscopy, to distinguish between these enantiomers. While, Tyr enantiomers provided no sensible CD signals at micromolar concentration levels, they exhibited remarkable and opposite CD spectra at these concentration levels in the presence of L-Cys/CdTe QDs. Under the optimized conditions, the CD signals of L- and D-Tyr enantiomers showed good linear relationships with the concentrations of both enantiomers over the range of 10-80 mu M with limit of detections (LODs) of 1.5 and 1.6 mu M, respectively. This method was also successfully applied to enantiomeric excess determination of Tyr at the total concentration of 50 mu M with a LOD of 1.2%.