Reduced haloperidol is an active metabolite of haloperidol . It is formed via reduction of haloperidol by ketone reductase. Reduced haloperidol inhibits radioligand binding to sigma-1 and dopamine D2 receptors (Kis = 1.4 and 31 nM, respectively) and stimulates brain-derived neurotrophic factor (BDNF) secretion from CCF-SSTG1 and U87MG astrocytic glial cells. It also inhibits norepinephrine, dopamine, and serotonin (5-HT) reuptake (Kis = 21, 25, and 33 μM, respectively, in COS-7 cells expressing the human transporters). Reduced haloperidol (0.5 mg kg) increases latency to paw withdrawal in mouse models of capsaicin- but not force-induced mechanical hypersensitivity.
Ro 04-5595 is a selective antagonist of NMDA receptors NR2B subunits. Ro 04-5595 had an EC 50 of 186 ± 32 nmol/L. Ro 04-5595 was predicted to bind the EVT-101 binding site, not the ifenprodil-binding site. Specific binding, defined with a new NR2B-specific antagonist Ro 04-5595 at 10 microM was fully inhibited by several compounds with the following rank order of affinities--Ro 25-6981 > CP-101,606 > Ro 04-5595 = ifenprodil >> eliprodil > haloperidol > spermine > spermidine > MgCl2 > CaCl2--and partially inhibited by competitive glutamate recognition site antagonists. Complementary high-resolution autoradiographic images using [3H]Ro04-5595 demonstrated strong binding in NR2B receptor-rich regions and low binding in cerebellum where NR2B concentration is low.
VU0477886 is a potent mGlu4 positive allosteric modulator (PAM) with robust efficacy in a standard preclinical Parkinson's disease model, haloperidol-induced catalepsy (HIC).
Acetyl β-endorphin (1-26) is a neuropeptide found in rat hippocampus, brain stem, and pituitary. It is also present in the human hypothalamus, where it comprises approximately 4.9% of total β-endorphin peptides. Acetyl β-endorphin (1-26) is produced through posttranslational processing of β-endorphin and is processed similarly in rat and human hypothalamus. Levels of acetyl β-endorphin (1-26) increase in the rat pars intermedia and brain stem following chronic administration of haloperidol .