The acetylcholinesterase (AChE) inhibitor donepezil is also a sigma1 receptor agonist. We examined whether donepezil binds to sigma1 receptors in the living human brain after a single oral administration. Dynamic positron emission tomography (PET) data acquisition using the selective sigma1 receptor ligand [11C]SA4503 was performed to evaluate quantitatively the binding of [11C]SA4503 to sigma1 receptors in eight healthy male volunteers. Each subject had a PET scan before and after receiving a single dose of donepezil (5 or 10 mg). The binding potential of [11C]SA4503 was calculated. Doses of 5 mg and 10 mg donepezil bound to sigma1 receptors in the human brain with occupancies of approximately 60% and approximately 75%, respectively, in a dose-dependent manner. This study demonstrated that donepezil binds to sigma1 receptors in the living human brain at therapeutic doses. Therefore, sigma1 receptors may be implicated in the pharmacological mechanism of donepezil in the human brain.
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http://dx.doi.org/10.1017/S1461145709990204 | DOI Listing |
Life Sci
January 2025
Department of Biochemistry, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt.
Aims: Sigma-1 receptor (S1R) activation was recently identified as a promising target for preventing diabetic nephropathy (DN) by mitigating hypoxia, oxidative stress, and inflammation. This study aimed to investigate the potential reno-protective effect of the S1R agonist afobazole against streptozotocin (STZ)-induced DN in rats compared to metformin.
Materials And Methods: Rats were split into six groups: the normal control group; the diabetic control group received STZ (55 mg/kg i.
Prog Neuropsychopharmacol Biol Psychiatry
January 2025
Louisiana State University, Department of Comparative Biomedical Sciences, Baton Rouge, LA 70803, United States of America. Electronic address:
Renewed interest in the clinical use of psychedelic drugs acknowledges their therapeutic effectiveness. It has also provided a changing frame of reference for older psychedelic drug study data, especially regarding concentrations of N, N-dimethyltryptamine (DMT) reported in rodent brains and recent discoveries in DMT receptor interactions in rat brain neurons and select brain areas. The mode of action of DMT in its newly defined role as a neuroplastogen, its effectiveness in treating neuropsychiatric disorders, and its binding to intracellular sigma-1 and 5HT2a receptors may define these possible roles.
View Article and Find Full Text PDFKorean J Physiol Pharmacol
January 2025
Department of Pharmacology, Catholic Kwandong University College of Medicine, Gangneung 25601, Korea.
Neurosteroids play an important role as endogenous neuromodulators that are locally produced in the central nervous system and rapidly change the excitability of neurons and the activation of microglial cells and astrocytes. Here we review the mechanisms of synthesis, metabolism, and actions of neurosteroids in the central nervous system. Neurosteroids are able to play a variety of roles in the central nervous system under physiological conditions by binding to membrane ion channels and receptors such as gamma-aminobutyric acid type A receptors, Nmethyl- D-aspartate receptors, L- and T-type calcium channels, and sigma-1 receptors.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
January 2025
Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA. Electronic address:
Background: There are no approved oral disease-modifying treatments for Alzheimer's disease (AD).
Objectives: The objective of this study was to assess efficacy and safety of blarcamesine (ANAVEX®2-73), an orally available small-molecule activator of the sigma-1 receptor (SIGMAR1) in early AD through restoration of cellular homeostasis including autophagy enhancement.
Design: ANAVEX2-73-AD-004 was a randomized, double-blind, placebo-controlled, 48-week Phase IIb/III trial.
Neuropharmacology
January 2025
Pharmacology and Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt; Pharmacology and Toxicology Department, Faculty of Pharmacy, King Salman International University (KSIU), South Sinai, 46612, Egypt.
Seizures can lead to cardiac dysfunction. Multiple pathways contribute to this phenomenon, of which the chaperone sigma-1 receptor (S1R) signaling represents a promising nexus between the abnormalities seen in both epilepsy and ensuing cardiac complications. The study explored the potential of Berberine (BER), a promising S1R agonist, in treating epilepsy and associated cardiac abnormalities in a pentylenetetrazol (PTZ) kindling rat model of epilepsy.
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