Prostaglandin (PG) E1 enhances formation of 3H-adenosine-3',5'-cyclic monophasphate (3H-cAMP) in platelets pulse-labeled with 3H-adenine. This response was assessed as an index of receptor sensitivity and of PG function. Prostagladin E1-stimulated 3H-cAMP accumulation in paltelets from schizophrenics was significantly reduced compared with control subjects. Platelet incorporation of 3H-adenine and basal 3H-cAMP accumulation. We discuss the results in terms of the possible role of PGs in the etiopathology of schizophrenia and derivative implications for treatment.
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http://dx.doi.org/10.1001/archpsyc.1980.01780220085010 | DOI Listing |
J Basic Clin Physiol Pharmacol
May 2016
Background: CB1 cannabinoid receptors (CB1Rs) stimulate Gi/o-dependent signaling pathways. CB1R-mediated cAMP increases were proposed to result from Gs activation, but CB1R-stimulated GTPγS binding to Gs has not heretofore been investigated.
Methods: Three models of CB1R-stimulated cAMP production were tested: pertussis toxin disruption of Gi/o in N18TG2 cells; L341A/A342L-CB1R expressed in Chinese hamster ovary (CHO) cells; and CB1 and D2 dopamine receptors endogenously co-expressed in MN9D cells.
BMC Pharmacol
June 2008
Institute of Cell Signalling, Medical School, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
Background: The H3 histamine receptor is a Gi-coupled GPCR that has been proven to exist in different agonist-induced states, including that defined by the protean agonist proxyfan. Several GPCRs are now known to exist in different states. For some of these, antagonist affinity measurement remain constant regardless of the state of the receptor, for others e.
View Article and Find Full Text PDFInt J Neuropsychopharmacol
June 2008
Stanley Research Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Lithium ions' inhibition of adenylyl cyclase (AC) has not been previously studied for the newly discovered AC isoforms. COS7 cells were transfected with each of the nine membrane-bound AC isoforms cDNAs with or without D1- or D2-dopamine receptor cDNA. AC activity was measured as [3H]cAMP accumulation in cells pre-incubated with [3H]adenine followed by incubation with phosphodiesterase inhibitors together with either the D1 agonist SKF-82958 alone, or forskolin, in the presence or absence of the D2 agonist quinpirole.
View Article and Find Full Text PDFBiochem Pharmacol
March 2007
Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav, México, D.F., Mexico; Sección Externa de Farmacología, Cinvestav, México, D.F., Mexico.
Androgen-independent prostate cancer cells DU-145 express a number of G protein-coupled receptors, including histamine H1 receptors. There is evidence for the presence of beta-adrenoceptors in the human prostate, and in this work we set out to characterise the expression of beta-adrenoceptors by DU-145 cells, their linking to cyclic AMP (cAMP) formation and the possible modulation by histamine H1 receptors of beta-adrenoceptor function. Saturation [3H]-dihydroalprenolol binding indicated that DU-145 cells express moderate levels of beta-adrenoceptors (22.
View Article and Find Full Text PDFJ Pharmacol Exp Ther
January 2007
Institute of Cell Signaling, Queen's Medical Centre, Nottingham NG7 2UH, UK.
The antagonist affinity for a given receptor is traditionally considered to be constant, reflecting the chemical nature of the specific ligand-receptor interaction. However, recent observations with all three beta-adrenoceptors have cast doubt on this basic pharmacological principle. The extent to which this finding applies to other G protein-coupled receptors and their interaction with different G proteins is unknown.
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