Gastrointestinal peptide hormone
Peptide YY
Peptide YY is a gastrointestinal hormone. Much feeding research concerns PYY(3-36) specifically; preserving that designation avoids attributing results for one form to every preparation identified only as PYY.
This is a research reference, not a product offered in the Asciende catalog. Published studies do not establish the identity, purity or availability of a commercial preparation.
Ligand, receptor and formulation
Keep entity and method together: transferring a result between formulations requires evidence even when their names overlap.
- Is the experimental entity the hormone, a fragment, an analog or a complete formulation?
- Does the readout measure receptor binding, an intracellular signal or an outcome in another system?
- Are species, expressed receptor, comparator and readout time reported?
Mechanism described in the literature
In rodent models, the 2002 study linked the feeding response to PYY(3-36) with the Y2 receptor through comparison with animals lacking that receptor. This delimits an experimental pathway, not a uniform response across studies.
Other names in the literature
- PYY
- Peptide YY
The initial finding and its scope
The initial publication combined feeding behavior with hypothalamic observations. In rodent studies, the authors described lower intake after PYY(3-36) exposure. An informative reading retains the molecular form and animal type; reducing the result to a general satiety label loses experimental detail.
Replication was not uniform
A 2004 communication reported that its authors could not reproduce the initial rodent results. This discrepancy must remain visible. It does not invalidate every previous experiment, but it prevents presenting the finding as readily reproducible under any conditions.
Observation time and behavioral context
Another 2004 study found a transient response in mice and differences related to habituation to the procedure. According to the literature, the response also occurred without a functional MC4 receptor. These provide concrete variables for interpreting divergence without resolving the entire controversy.
Questions and answers
Does a brief observation represent cumulative intake?
No. The follow-up study distinguished an early response from a later measurement without a difference, making observation period important.
Should discrepant findings be omitted when positive studies exist?
No. Replication results and conditions that might explain them are part of the evidence on PYY.
Sources
- Gut hormone PYY(3-36) physiologically inhibits food intake. — Nature, 2002
- Gut hormone PYY(3-36) physiologically inhibits food intake.
- Physiology: does gut hormone PYY3-36 decrease food intake in rodents? — Nature, 2004
- Physiology: does gut hormone PYY3-36 decrease food intake in rodents?
- Peptide YY3-36 inhibits food intake in mice through a melanocortin-4 receptor-independent mechanism. — Endocrinology, 2004
- Peptide YY3-36 inhibits food intake in mice through a melanocortin-4 receptor-independent mechanism.