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Study · Measured the body's own peptide · 1994

5 results

Diurnal rhythm of plasma delta-sleep-inducing peptide in humans: evidence for positive correlation with body temperature and negative correlation with rapid eye movement and slow wave sleep.

Friedman TC, Garcia-Borreguero D, Hardwick D, Akuete CN, Stambuk MK, Dorn LD, Starkman MN, Loh YP, Chrousos GP

The Journal of clinical endocrinology and metabolism1 May 1994Cited by 6 (Europe PMC)

PMID8175965 (opens in a new tab)DOI10.1210/jcem.78.5.8175965 (opens in a new tab)PepBankPUB-08175965
Publisher pagePubMedAsk about this study
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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 study5

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

Natural levels measured5

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. 01HumanEndogenous levelObservational studyOther

    In normal volunteers, plasma DSIP-like immunoreactivity showed a distinct diurnal rhythm, with the maximum at 1500 h and the minimum at 0100 h.

    In plain wordsIn healthy volunteers, the body's own DSIP-like levels in blood followed a daily rhythm, highest mid-afternoon and lowest after midnight.

    Peptide
    Delta sleep-inducing peptide (DSIP)
    Outcome
    Not applicableDiurnal rhythm of plasma DSIP-LI
    Study

    n = 12

    Outcome group
    Sleep · Sleep

    Source sentences

    Summary
    We found a distinct diurnal rhythm for plasma DSIP-LI levels, with the maximum at 1500 h and the minimum at 0100 h.
    1 context sentence
    Summary · context
    We, therefore, measured plasma DSIP-LI levels every 30 min for 24 h in 12 normal volunteers in whom we obtained simultaneous polygraphic recordings.

    This result measures the body's own Delta sleep-inducing peptide (DSIP). Nobody was given the peptide. It is not evidence about taking it.

  2. 02HumanEndogenous levelObservational studyOther

    In normal volunteers, plasma DSIP-like immunoreactivity was substantially lower in REM sleep than in the awake state.

    In plain wordsIn healthy volunteers, the body's own DSIP-like levels in blood were lower during REM sleep than when awake.

    Peptide
    Delta sleep-inducing peptide (DSIP)
    Outcome
    DecreasePlasma DSIP-LI in REM sleep versus wake
    Study

    n = 12

    Outcome group
    Sleep · Sleep

    Measurements

    P value
    < 0.005
    REM sleep versus awake

    Source sentences

    Summary
    DSIP-LI levels were substantially lower in rapid eye movement sleep (P < 0.005)
    1 context sentence
    Summary · context
    We, therefore, measured plasma DSIP-LI levels every 30 min for 24 h in 12 normal volunteers in whom we obtained simultaneous polygraphic recordings.

    This result measures the body's own Delta sleep-inducing peptide (DSIP). Nobody was given the peptide. It is not evidence about taking it.

  3. 03HumanEndogenous levelObservational studyOther

    In normal volunteers, plasma DSIP-like immunoreactivity was somewhat lower in slow wave sleep than in the awake state.

    In plain wordsIn healthy volunteers, the body's own DSIP-like levels in blood were slightly lower during deep sleep than when awake.

    Peptide
    Delta sleep-inducing peptide (DSIP)
    Outcome
    DecreasePlasma DSIP-LI in slow wave sleep versus wake
    Study

    n = 12

    Outcome group
    Sleep · Sleep

    Measurements

    P value
    < 0.05
    slow wave sleep versus awake

    Source sentences

    Summary
    somewhat lower in SWS (P < 0.05) compared to awake values
    1 context sentence
    Summary · context
    We, therefore, measured plasma DSIP-LI levels every 30 min for 24 h in 12 normal volunteers in whom we obtained simultaneous polygraphic recordings.

    This result measures the body's own Delta sleep-inducing peptide (DSIP). Nobody was given the peptide. It is not evidence about taking it.

  4. 04HumanEndogenous levelObservational studyOther

    In normal volunteers, plasma DSIP-like immunoreactivity did not rise before, during or after a significant percentage of slow wave sleep episodes.

    In plain wordsIn healthy volunteers, the body's own DSIP-like levels in blood did not rise around deep sleep episodes.

    Peptide
    Delta sleep-inducing peptide (DSIP)
    Outcome
    No significant changePlasma DSIP-LI before, during or after slow wave sleep episodes
    Study

    n = 12

    Outcome group
    Sleep · Sleep

    Source sentences

    Summary
    DSIP-LI levels did not rise before, during, or after a significant percentage of episodes of SWS.
    1 context sentence
    Summary · context
    We, therefore, measured plasma DSIP-LI levels every 30 min for 24 h in 12 normal volunteers in whom we obtained simultaneous polygraphic recordings.

    This result measures the body's own Delta sleep-inducing peptide (DSIP). Nobody was given the peptide. It is not evidence about taking it.

  5. 05HumanEndogenous levelObservational studyOther

    In normal volunteers, the diurnal rhythm of plasma DSIP-like immunoreactivity closely followed that of body temperature.

    In plain wordsIn healthy volunteers, the daily rhythm of the body's own DSIP-like levels closely matched the daily rhythm of body temperature.

    Peptide
    Delta sleep-inducing peptide (DSIP)
    Outcome
    Not applicableCorrelation of DSIP-LI rhythm with body temperature
    Study

    n = 12

    Outcome group
    Sleep · Sleep

    Measurements

    r2
    0.66
    DSIP-LI versus body temperature

    Source sentences

    Summary
    We found, however, that the diurnal rhythm of DSIP-LI closely followed that of body temperature with a high degree of correlation (r2 = 0.66; P < 0.0001).
    1 context sentence
    Summary · context
    We, therefore, measured plasma DSIP-LI levels every 30 min for 24 h in 12 normal volunteers in whom we obtained simultaneous polygraphic recordings.

    This result measures the body's own Delta sleep-inducing peptide (DSIP). 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

    10 Oct 2026, 08:55 UTC

    Study results updated

  2. Version 1

    9 Oct 2026, 03:04 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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