Novel [11C]-labeled Radioligands for Imaging Sigma-1 Receptor in the Brain Using Positron Emission Tomography (PET)

481Introduction: The sigma-1 receptor is recognized as a unique class of non-G protein coupled, non-ionotropic intracellular chaperone protein within the mitochondria-associated endoplasmic reticulum (ER) membranes [1]. It consists of 223 amino acids with a molecular weight of 25.3 kDa. The X-ray structure of sigma-1 receptor showed a membrane-bound trimeric assembly with one transmembrane region [2]. The sigma-1 receptor plays a major role in various pathological conditions in the periphery (e.g. vascular diseases, cancer) and in the central nervous system (CNS), where they are implicated in several neuropsychiatric and neurodegenerative disorders including depression, epilepsy, neuropathic pain, Parkinson`s disease (PD) and Alzheimer`s disease (AD) [1, 3]. Imaging of sigma-1 receptor in brain using positron emission tomography (PET) could serve as a noninvasively tool for elucidate the distribution and functional roles in vivo and enhance the understanding of the disease`s pathophysiology. Moreover, sigma-1 receptor PET tracers can be used for target validation, visualization and quantification of metabolic and biochemical processes as well as diagnosis and prognosis of these CNS diseases [4-6]. Herein, we describe the radiosynthesis, in vivo PET/CT imaging and ex vivo autoradiography of two novel sigma-1 receptor radioligands based on pyrimidine scaffold [7], [11C]HCC900424 (1) and [11C]HCC900329 (2). The results showed that these two probes have high specificity, good sel...
Source: Journal of Nuclear Medicine - Category: Nuclear Medicine Authors: Tags: Preclinical Probes for Neuroimaging Source Type: research