Comparative analysis of pharmacological properties of xanomeline and N-desmethylclozapine in rat brain membranes

Abstract

The agonistic effects on the mAChRs (particularly M1 subtype, and also probably M4 subtype), the 5-HT1A receptor and the δ-opioid receptor expressed in native brain tissues, some of which are common to both compounds and others specific to either, likely shape the unique beneficial effectiveness of both compounds in the treatment for schizophrenic patients. These characteristics provide us with a clue to develop newer antipsychotics, beyond the framework of dopamine D2 receptor antagonism, that are effective not only on positive symptoms but also on negative symptoms and/or cognitive/affective impairment.

Optimization and pharmacological characterization of receptor‐mediated Gi/o activation in postmortem human prefrontal cortex

“…The [ 35 S]GTPγS binding assay using filtration techniques was performed according to the methods described previously, with minor modifications. In a standard experiment, human prefrontal cortical membranes were thawed slowly, and aliquots equivalent to 60 μg protein were incubated at 30ºC for 60 minutes in 500 μL of 50 mmol/L Tris‐HCl buffer (pH 7.4) containing 0.2 nmol/L [ 35 S]GTPγS, 5 mmol/L MgCl 2 , 0.1 mmol/L ethylenediaminetetraacetic acid, 0.2 mmol/L ethylene glycolbis(2‐aminoethylether)‐ N , N , N , N ‐tetraacetic acid (EGTA), 0.2 mmol/L DTT, 100 mmol/L NaCl, 50 μmol/L GDP and the compound(s) of interest at the indicated concentration(s).…”

Xanomeline Protects Cortical Cells From Oxygen-Glucose Deprivation via Inhibiting Oxidative Stress and Apoptosis

“…Xanomeline increases soluble amyloid precursor protein (APP) release from Chinese hamster ovary-m1 cells (Eckols et al, 1995). Moreover, xanomeline had agonistic activity at the M1 muscarinic acetylcholine receptor in all brain regions (Odagaki et al, 2016). Thus, we conclude that xanomeline may have a direct impact on brain function.…”

Functional coupling between adenosine A1 receptors and G-proteins in rat and postmortem human brain membranes determined with conventional guanosine-5′-O-(3-[35S]thio)triphosphate ([35S]GTPγS) binding or [35S]GTPγS/immunoprecipitation assay

“…The [ 35 S]GTPγS binding assay using filtration techniques were performed according to the methods described previously [16]. In brief, brain membranes equivalent to 10-20 μg protein (rat) or 60 μg protein (human) were incubated in duplicate at 30°C for 60 min in 500 μL of 50 mM Tris-HCl buffer (pH 7.4) containing 0.2 nM [ 35 S]GTPγS, 5 mM MgCl 2 , 0.1 mM ethylenediaminetetraacetic acid, 0.2 mM ethylene glycolbis(2-aminoethylether)-N,N,N,N-tetraacetic acid (EGTA), 0.2 mM dithiothreitol, 100 mM NaCl, 20 μM (rat) or 50 μM (human) GDP, and the compound of interest at the indicated concentration.…”

“…The [ 35 S]GTPγS binding/immunoprecipitation assay was performed according to the methods described previously [10,16]. The brain membranes were diluted with 50 mM Tris-HCl buffer (pH 7.4) to contain 20 μg protein (rat) or 80 μg protein (human) in 100 μL and were incubated with the compound of interest diluted in 50 μL distilled water at room temperature for 30 min in 1.5 mL polypropylene microtube.…”

“…10,16], in rat and postmortem human brain membranes. In postmortem human prefrontal cortical membranes, the receptor subtype involved in adenosineinduced [ 35 S]GTPγS binding to Gα i-3 was pharmacologically characterized as adenosine A 1 receptor[10].…”