A series of pyrrolizidine esters, amides, and ureas was prepared and tested for 5-HT(4) and 5-HT(3) receptor binding, 5-HT(4) receptor agonism in the rat tunica muscularis mucosae (TMM) assay, and for 5-HT(3) receptor-mediated functional antagonism in the Bezold-Jarisch reflex assay. Several pyrrolizidine derivatives were identified with high affinity for the 5-HT(4) receptor, including benzamide 12a (SC-53116), a potent and selective 5-HT(4) partial agonist that exhibits efficacy in promoting antral contractions and activity in promoting gastric emptying in canine models. Also discovered were 5-HT(4) receptor antagonists, including imidazopyridine amide 12h (SC-53606), which is a potent and selective 5-HT(4) receptor antagonist with a pA(2) value of 8.13 in the rat TMM assay. N-Methyl indole ester 13d was identified as a potent 5-HT(4) antagonist with a pA(2) value of 8.93. High selectivity was observed for these pyrrolizidine derivatives versus other monoamine receptors, including 5-HT(1), 5-HT(2), D(1), D(2), alpha(1), alpha(2), and beta receptors.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jm0509501 | DOI Listing |
Background: Tau protein tangles have been recently shown to accumulate in multiple brainstem nuclei in pre-cortical Alzheimer's disease (AD) stages. The impact of neurotransmission alterations on brain atrophy and their genetic correlates in AD remain unexplored. Therefore, the aims of this study were: 1) to investigate associations between grey matter (GM) loss across the AD continuum and the distribution of multiple neurotransmitter receptors/transporters; 2) to investigate the impact of polygenic risk scores for AD (PRSs) on such associations.
View Article and Find Full Text PDFArch Razi Inst
June 2024
Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran.
In the present study, the mechanisms involved in scopolamine-induced memory impairment have been investigated. The molecular events that take place during memory mostly include mechanisms that are seen in the acquisition phase. Results showed that one of the mechanisms of memory destruction caused by scopolamine, in addition to weakening the cholinergic system, is the indirect effect of scopolamine on other neurotransmitter systems, including the glutamatergic system.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Management, Bar-Ilan University, Ramat Gan, 5290002, Israel.
Int J Med Sci
December 2024
Department of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 50612, Republic of Korea.
J Psychiatr Res
November 2024
Neurobiology Research Unit and BrainDrugs, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark; Mental Health Center Copenhagen, Copenhagen University Hospital - Mental Health Services CPH, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!