N-Methylation of backbone amide bonds was conducted on a tetrapeptide that had been identified previously (Shiosaki, K.; et al. J. Med. Chem. 1991, 34, 2387-2842) as a potent and selective CCK-A agonist. N alpha-Methylation at the position corresponding to Asp32 (CCK-33 numbering) was consistent with high affinity, efficacy, and selectivity for the CCK-A receptor. Combination of this (N-Me)Asp with the (N-Me)Phe modification also provided a highly active analogue. The observation of parallel structure-binding affinity profiles with respect to sites of N-methylation in the C-terminal regions of tetrapeptide vs heptapeptide CCK analogues suggests that the two series interact similarly with the CCK-A receptor.
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http://dx.doi.org/10.1021/jm00031a013 | DOI Listing |
Bioengineering (Basel)
January 2025
Department of Ultrasound, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 200120, China.
Background: Cholesterol gallstone disease (CGS) is often accompanied by gallbladder contraction dysfunction and chronic inflammation, but effective therapeutic options remain limited. This study investigates whether a low-intensity pulsed ultrasound (LIPUS) treatment can improve gallbladder motility and alleviate chronic inflammation while exploring the underlying mechanisms.
Methods: Gallbladder motility was assessed through in vitro and in vivo contraction tests, while bile condition was evaluated by observing bile crystal clearance.
Life Sci
January 2025
College of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology, Chinese Academy of Medical Sciences, Shijiazhuang, Hebei Province, China; Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, Hebei Province, China; Hainan Tropical Forensic Medicine Academician Workstation, Haikou, Hainan Province, China. Electronic address:
The vagus nerves are important carriers of sensory information from the viscera to the central nervous system. Emerging evidence suggests that sensory signaling through the right, but not the left, vagus nerve evokes striatal dopamine release and reinforces appetitive behaviors. However, the extent to which differential gene expression within vagal sensory neurons contributes to this asymmetric reward-related signaling remains unknown.
View Article and Find Full Text PDFPLoS Biol
July 2024
Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, United States of America.
Development of optimal therapeutics for disease states that can be associated with increased membrane cholesterol requires better molecular understanding of lipid modulation of the drug target. Type 1 cholecystokinin receptor (CCK1R) agonist actions are affected by increased membrane cholesterol, enhancing ligand binding and reducing calcium signaling, while agonist actions of the closely related CCK2R are not. In this work, we identified a set of chimeric human CCK1R/CCK2R mutations that exchange the cholesterol sensitivity of these 2 receptors, providing powerful tools when expressed in CHO and HEK-293 model cell lines to explore mechanisms.
View Article and Find Full Text PDFEcotoxicol Environ Saf
August 2024
Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China. Electronic address:
Fish egg poisoning is a serious and neglected public menace that kills hundreds of people and numerous poultry each year. Freshwater groupers (Acrossocheilus fasciatus) are common food fish in the southeastern regions of China. Their toxic eggs are regarded as a significant public health concern.
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