Serotonergic agonists stimulate inositol lipid metabolism in rabbit platelets
The metabolism of inositol phospholipids in response to serotonergic agonists was investigated in rabbit platelets. In platelets prelabelled with (/sup 3/H)-inositol, in a medium containing 10 mM LiCl which blocks the enzyme inositol-1-phosphatase, 5-hydroxytryptamine (5-HT) caused a dose-dependent accumulation of inositol phosphates (IP). This suggests a phospholipase-C-mediated breakdown of phosphoinositides. Ketanserin, a selective 5-HT/sub 2/ antagonist, was a potent inhibitor of the 5-HT response, with a Ki of 28 nM, indicating that 5-HT is activating receptors of the 5-HT/sub 2/ type in the platelet. Lysergic acid diethylamide (LSD) and quipazine also caused dose-related increases in inositol phosphate levels, though these were considerably less than those produced by 5-HT. These results show that relatively small changes in phosphoinositide metabolism induced by serotonergic agonists can be investigated in the rabbit platelet, and this cell may therefore be a useful model for the study of some 5-HT receptors. 30 references, 4 figures.
- Research Organization:
- Radcliffe Infirmary, Oxford, England
- OSTI ID:
- 5127161
- Journal Information:
- Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 37:17; ISSN LIFSA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BIOLOGICAL MATERIALS
BIOLOGICAL MODELS
BLOOD
BLOOD CELLS
BLOOD PLATELETS
BODY FLUIDS
CARBOXYLESTERASES
CARBOXYLIC ACIDS
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ENZYME INHIBITORS
ENZYMES
ESTERASES
ESTERS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
INDOLES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPASE
LIPIDS
LYSERGIC ACID
MAMMALS
MATERIALS
METABOLISM
NEUROREGULATORS
ORGANIC ACIDS
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ORGANIC NITROGEN COMPOUNDS
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OXYGEN COMPOUNDS
PHOSPHATASES
PHOSPHATES
PHOSPHOLIPIDS
PHOSPHORUS COMPOUNDS
PYRROLES
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SEROTONIN
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TRITIUM COMPOUNDS
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