Abstract
alpha 1-Adrenergic activation stimulated phosphorylase and phosphoinositide turnover in hepatocytes from guinea pigs, rats and rabbits. Chlorethylclonidine inhibited these effects in rat and rabbit cells but not in guinea pig hepatocytes; low concentrations of 5-methyl urapidil blocked the alpha 1 actions in guinea pig and rabbit liver cells, but not in rat hepatocytes. Binding competition experiments also showed high affinity for 5-methyl urapidil in liver membranes from guinea pigs and rabbits and low affinity in those from rats. The data indicated that guinea pig hepatocytes express alpha 1A-, rat hepatocytes alpha 1B- and rabbit hepatocytes alpha 1C- adrenoceptors. This was confirmed by Northern analysis using receptor subtype-selective probes.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Adrenergic alpha-Antagonists / pharmacology
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Animals
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Blotting, Northern
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Cells, Cultured
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Guinea Pigs
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Inositol 1,4,5-Trisphosphate / metabolism*
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Kinetics
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Liver / drug effects
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Liver / metabolism*
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Norepinephrine / pharmacology
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Piperazines / pharmacology
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Prazosin / pharmacology
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Propranolol / pharmacology
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RNA / genetics
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RNA / isolation & purification
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Rabbits
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Rats
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Rats, Inbred Strains
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Receptors, Adrenergic, alpha / drug effects
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Receptors, Adrenergic, alpha / genetics
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Receptors, Adrenergic, alpha / physiology*
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Species Specificity
Substances
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Adrenergic alpha-Antagonists
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Piperazines
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Receptors, Adrenergic, alpha
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5-methylurapidil
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RNA
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Inositol 1,4,5-Trisphosphate
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Propranolol
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Norepinephrine
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Prazosin