Two kinds of tryptamine receptor
British Journal of Pharmacology and Chemotherapy
|September 1, 1957
Summary
Guinea-pig ileum contains two tryptamine receptors: M receptors, blocked by morphine, and D receptors, blocked by dibenzyline. These receptors are likely located in nervous tissue and muscles, respectively.
Area of Science:
- Pharmacology
- Neuroscience
- Gastroenterology
Background:
- The guinea-pig ileum is a common model for studying drug-receptor interactions.
- Tryptamine receptors play a role in modulating smooth muscle contraction and neurotransmission.
Purpose of the Study:
- To differentiate and characterize the M and D tryptamine receptors in the guinea-pig ileum.
- To investigate the localization of these receptors within the ileum tissue.
Main Methods:
- Pharmacological characterization using specific blocking agents like morphine and dibenzyline.
- Administration of various drugs including atropine, cocaine, methadone, lysergic acid diethylamide, dihydroergotamine, and 5-benzyloxygramine.
- Observation and analysis of the effects on guinea-pig ileum contractions.
Main Results:
- Two distinct tryptamine receptors, M and D, were identified based on differential blockade.
- M receptors were inhibited by morphine, atropine, cocaine, and methadone, suggesting a neuronal location.
- D receptors were inhibited by dibenzyline, lysergic acid diethylamide, dihydroergotamine, and 5-benzyloxygramine, indicating a muscular location.
Conclusions:
- The guinea-pig ileum possesses at least two types of tryptamine receptors.
- M receptors are likely situated in nervous tissue, while D receptors are probably located in smooth muscle.
- This differentiation aids in understanding tryptaminergic signaling in the gastrointestinal tract.
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