A Comparative Study of the Effects of δ-Aminolaevulinic Acid and the G ABAAAgonist, Muscimol, in Rat Jejunal Preparations
| Autor: | John M. Turner, Michael R. Moore, Margaret G. Cutler |
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| Rok vydání: | 1991 |
| Předmět: |
Agonist
medicine.medical_specialty medicine.drug_class Health Toxicology and Mutagenesis In Vitro Techniques Biology Bicuculline Toxicology chemistry.chemical_compound Internal medicine medicine Animals Picrotoxin Pharmacology Muscimol GABAA receptor Antagonist Drug Synergism Muscle Smooth Rats Inbred Strains Biological activity Aminolevulinic Acid medicine.disease Rats Jejunum Porphyria Endocrinology nervous system chemistry Muscle Contraction medicine.drug |
| Zdroj: | Pharmacology & Toxicology. 69:52-55 |
| ISSN: | 1600-0773 0901-9928 |
| DOI: | 10.1111/j.1600-0773.1991.tb00409.x |
| Popis: | Preparations of rat jejunum were tested for their responsiveness to the GABAA receptor agonist, muscimol, and to the haem precursor, delta-aminolaevulinic acid (ALA). Both muscimol (1.0-30 microM) and ALA (1.0 microM-3.0 mM) elicited a concentration-dependent increase in tone. Pretreatment with the GABAA antagonist, bicuculline (10(-5) M), blocked effects of muscimol at all concentrations tested and attenuated effects of 0.3 mM ALA. However, bicuculline enhanced responsiveness of the preparations to ALA at low concentrations (0.01-0.05 microM), as also did picrotoxin (10(-5) M), eliciting a significant increase of tone. The significance of these findings is discussed. This finding of pharmacological activity by ALA at concentrations comparable with its blood levels during acute attacks of intermittent porphyria provides support for the proposal that is may play a role in the aetiology of the gastrointestinal manifestations of this disease. |
| Databáze: | OpenAIRE |
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