Purpose: To determine whether brain and plasma equilibrium of a proposed PET tracer for 5-HT(1A), [(18)F]FPWAY, can be achieved in a sufficiently short time for practical use of the brain to plasma equilibrium distribution ratio (DR) to monitor receptor availability with and without isoflurane anesthesia.
Methods: Awake (n=4) and isoflurane-anesthetized (n=4) rats were administered a continuous 60 min intravenous infusion of [(18)F]FPWAY with timed arterial blood sampling. Brains of the isoflurane-anesthetized rats were scanned with the ATLAS small animal PET scanner; awake rats were not. All rats were killed at 60 min and scanned postmortem for 15 min, followed by brain slicing for autoradiography. Several regions of interest (ROIs) were defined in the PET images as well as in the autoradiographic images. Regional DRs were calculated as total activity in the brain ROI divided by plasma [(18)F]FPWAY activity.
Results: DRs in the anesthetized animals were constant between 30 and 60 min, indicating that near equilibrium between brain and plasma had been achieved by approximately 30 min. DRs determined from postmortem PET data were higher in the isoflurane-anesthetized rats by 24% (not significant) and 33% (p=0.065) in whole brain and hippocampus, respectively. DRs determined from autoradiographic data were greater in isoflurane-anesthetized rats in medial hippocampus, lateral hippocampus, and cerebellum by 33% (p=0.054), 63% (p<0.01), and 32% (p<0.05), respectively.
Conclusion: [(18)F]FPWAY could be an appropriate ligand for monitoring changes in receptor availability in the serotonergic system using a bolus/infusion paradigm. One possible explanation for higher DRs in anesthetized rats may be a reduction in endogenous 5-HT secretion under isoflurane anesthesia.
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Front Biosci (Landmark Ed)
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Division of Molecular Psychiatry, Center of Mental Health, University of Hospital Würzburg, 97080 Würzburg, Germany.
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Decompensated cirrhosis is characterized by systemic inflammation and innate and adaptive immune dysfunction. Hepatic encephalopathy (HE) is a prevalent and debilitating condition characterized by cognitive disturbances in which ammonia and inflammation play a synergistic pathogenic role. Extraskeletal functions of vitamin D include immunomodulation, and its deficiency has been implicated in immune dysfunction and different forms of cognitive impairment.
View Article and Find Full Text PDFPharmaceuticals (Basel)
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School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China.
Alzheimer's disease (AD) is the leading cause of dementia among the elderly, yet effective treatments remain elusive. Total saikosaponins (TSS), the primary bioactive components in , have shown promising therapeutic effects against AD in previous studies. : To delve deeper into the mechanisms underlying the therapeutic role of TSS in AD, we investigated its neuroprotective effects and associated molecular mechanisms in APP/PS1 mice.
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Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt.
: Mirtazapine (MRZ) is a psychotropic drug prescribed to manage serious sorts of depression. By virtue of its extensive initial-pass metabolic process with poor water solubility, the ultimate bioavailability when taken orally is a mere 50%, necessitating repeated administration. The current inquiry intended to fabricate nose-to-brain chitosan-grafted cationic leciplexes of MRZ (CS-MRZ-LPX) to improve its pharmacokinetic weaknesses and boost the pharmacodynamics aspects.
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Infectious Disease Unit, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy.
Brain abscesses are invasive infections of the central nervous system with a high level of treatment complexity especially in pediatric patients. Here, we describe a 3-month-old infant with multiple brain abscesses caused by methicillin-susceptible (MSSA). The patient was initially treated with empirical antibiotics (ceftriaxone, metronidazole, vancomycin).
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