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Updated: Aug 12, 2026
A Plate-Based Assay for the Measurement of Endogenous Monoamine Release in Acute Brain Slices
Published on: August 11, 2021
Variations in the monoamine oxidase-inhibitory activity ("tribulin?") in pig's urine
Abstract:
Sandler and his colleagues (see Sandler, 1982) have demonstrated the presence of an endogenous inhibitor of the enzyme monoamine oxidase (MAO) and of benzodiazepine receptor binding in the urine and blood plasma of man and rat. The concentrations of this material increased under stress conditions and it has been named "tribulin". In the present experiments MAO-inhibitory activity was found in extracts of urine and plasma samples of domestic pigs. Evidence was obtained that the inhibitory activity was higher when pigs experienced slight discomfort. Thus it appears that pigs produce a substance similar to tribulin. It may become possible to use such MAO-inhibitory activity as an indicator in the assessment of interaction with the environment in pig husbandry.
Insights
Researchers found a substance in pigs similar to human tribulin, which inhibits monoamine oxidase (MAO). This MAO-inhibitory activity increased with mild stress, suggesting its potential use in assessing pig welfare and environmental interactions.
Area of Science:
- Biochemistry
- Animal Physiology
- Veterinary Science
Background:
- An endogenous inhibitor, tribulin, affecting monoamine oxidase (MAO) and benzodiazepine receptor binding, has been identified in humans and rats.
- Tribulin levels increase under stress conditions.
Purpose of the Study:
- To investigate the presence of MAO-inhibitory activity in domestic pigs.
- To determine if this activity is influenced by environmental stressors.
Main Methods:
- Extraction of MAO-inhibitory substances from urine and plasma samples of domestic pigs.
- Assay of MAO-inhibitory activity in relation to varying levels of discomfort.
Main Results:
- MAO-inhibitory activity was detected in pig urine and plasma extracts.
- The inhibitory activity was found to be higher in pigs experiencing slight discomfort, suggesting a stress-related response.
Conclusions:
- Domestic pigs produce a substance with MAO-inhibitory activity, similar to tribulin found in humans.
- This MAO-inhibitory activity may serve as a biomarker for assessing pig welfare and their interaction with the environment in agricultural settings.
