Skip to content

Study · Measured the body's own peptide · 1996

2 results

Vasoactive intestinal peptide concentrations in turkey hypophysial portal blood differ across the reproductive cycle.

Youngren O, Chaiseha Y, Phillips R, El Halawani M

General and comparative endocrinology1 Sept 1996Cited by 34 (Europe PMC)

PMID8812403 (opens in a new tab)DOI10.1006/gcen.1996.0128 (opens in a new tab)PepBankPUB-08812403
Publisher pagePubMedAsk about this study
Jump to 2 results

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study2

No result from this study comes from a test of the peptide.

Natural levels measured2

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

  1. 01AnimalEndogenous levelAnimal study (in vivo)Mechanism

    In turkeys, VIP concentrations in hypophysial portal blood were 2.5- to 13.5-fold greater than in the general circulation.

    In plain wordsIn turkeys, the body's own VIP was 2.5 to 13.5 times higher in blood going to the pituitary than in general blood.

    Peptide
    Vasoactive intestinal peptide (VIP, aviptadil)
    Outcome
    IncreaseVIP concentration in hypophysial portal blood versus general circulation
    Study

    turkeyn: not reported in source

    Comparator
    General circulation
    Outcome group
    Endogenous peptide levels · Endocrine and hormones

    Measurements

    Fold difference in VIP concentration
    2.5 to 13.5 fold
    portal blood vs general circulation

    Source sentences

    Summary
    VIP concentrations in hypophysial portal blood were 2.5- to 13.5-fold greater than in the general circulation.
    1 context sentence
    Summary · context
    Hypophysial portal blood was collected for the first time in an avian species using a dorsal approach through the third ventricle and median eminence of the turkey.

    This result measures the body's own Vasoactive intestinal peptide (VIP, aviptadil). Nobody was given the peptide. It is not evidence about taking it.

  2. 02AnimalEndogenous levelAnimal study (in vivo)Mechanism

    In turkey hens, portal blood VIP was lowest in nonphotostimulated, reproductively inactive hens and highest in incubating hens, and the differences mirrored plasma prolactin.

    In plain wordsIn turkey hens, the body's own VIP in pituitary blood changed with the reproductive stage and was highest in incubating hens.

    Peptide
    Vasoactive intestinal peptide (VIP, aviptadil)
    Outcome
    MixedVIP concentration in portal blood across the reproductive cycle
    Study

    turkeyn: not reported in source

    Outcome group
    Endogenous peptide levels · Endocrine and hormones

    Measurements

    VIP concentration
    231.8 pg/ml
    nonphotostimulated, reproductively inactive hens
    VIP concentration
    1108.1 pg/ml
    incubating hens
    VIP concentration
    372.5 pg/ml
    laying hens
    VIP concentration
    715.3 pg/ml
    photorefractory hens

    Source sentences

    Summary
    VIP concentrations were lowest in portal blood of nonphotostimulated, reproductively inactive hens (231.8 +/- 26.4 pg/ml) and highest in incubating hens (1108.1 +/- 363.7 pg/ml), while laying, and photorefractory hens were intermediate at 372.5 +/- 95.6 and 715.3 +/- 338.5 pg/ml, respectively.
    2 context sentences
    Summary · context
    These differences in concentration of VIP in portal blood mirrored those of PRL in the general circulation and support other evidence that VIP is the avian PRL-releasing factor.
    Summary · context
    Hypophysial portal blood was collected for the first time in an avian species using a dorsal approach through the third ventricle and median eminence of the turkey.

    This result measures the body's own Vasoactive intestinal peptide (VIP, aviptadil). Nobody was given the peptide. It is not evidence about taking it.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    12 Oct 2026, 12:58 UTC

    Study results updated

  2. Version 1

    9 Oct 2026, 12:41 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

PepBank is a research reference. Talk to a doctor before you use any peptide.