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), Vol. 37:17
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
PHOSPHOLIPIDS
METABOLISM
BIOLOGICAL MODELS
BLOOD PLATELETS
DOSE-RESPONSE RELATIONSHIPS
ENZYME INHIBITORS
LIPASE
LYSERGIC ACID
PHOSPHATASES
PHOSPHATES
RABBITS
RECEPTORS
SEROTONIN
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALOIDS
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLESTERASES
CARBOXYLIC ACIDS
DRUGS
ENZYMES
ESTERASES
ESTERS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
INDOLES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
MATERIALS
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PYRROLES
RADIOPROTECTIVE SUBSTANCES
SYMPATHOMIMETICS
TRYPTAMINES
VERTEBRATES
550501* - Metabolism- Tracer Techniques