A time-dependent peak of oxytocin exists in cerebrospinal fluid but not in plasma of humans.

Amico JA, Tenicela R, Johnston J, Robinson AG

The Journal of clinical endocrinology and metabolism1 Nov 1983Cited by 85 (Europe PMC)

PMID6619269DOI10.1210/jcem-57-5-947PepBankPUB-06619269

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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 study11

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

Natural levels measured7

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.

01HumanEndogenous levelObservational studyOther
In six patients with sequential cerebrospinal fluid sampling, endogenous oxytocin at 1200 h (6.41 +/- 1.13 and 5.06 +/- 0.58 microU/ml) was significantly higher (p less than 0.05) than at 0600 h (2.50 +/- 0.65 microU/ml).
In plain wordsIn six patients, the body's own oxytocin level in spinal fluid was higher at noon than at 0600 h.
Peptide
Oxytocin
Outcome
IncreaseCSF oxytocin concentration at 1200 h versus 0600 h
Study
n = 6
Comparator
0600 h
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
of OT at 1200 h, 6.41 +/- 1.13 microU/ml and 5.06 +/- 0.58 microU/ml, to be significantly higher (p less than 0.05) than mean levels of OT at 0600 h, 2.50 +/- 0.65 microU/ml
1 context sentence(design, population, supporting numbers)
Summary · context
Oxytocin (OT) and the oxytocin-neurophysin (OT-Np) were measured by RIA in samples of cerebrospinal fluid (CSF) obtained sequentially at 0600, 1200, 1800, and 2400 h from six patients in whom intrathecal catheters were temporarily placed for CSF rhinorrhea.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926901
02HumanEndogenous levelObservational studyOther
In six patients with sequential cerebrospinal fluid sampling, endogenous oxytocin at 1200 h (6.41 +/- 1.13 and 5.06 +/- 0.58 microU/ml) was significantly higher (p less than 0.05) than at 1800 h (2.63 +/- 0.61 and 2.64 +/- 1.21 microU/ml).
In plain wordsIn six patients, the body's own oxytocin level in spinal fluid was higher at noon than at 1800 h.
Peptide
Oxytocin
Outcome
IncreaseCSF oxytocin concentration at 1200 h versus 1800 h
Study
n = 6
Comparator
1800 h
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
of OT at 1200 h, 6.41 +/- 1.13 microU/ml and 5.06 +/- 0.58 microU/ml, to be significantly higher (p less than 0.05) than mean levels of OT at 0600 h, 2.50 +/- 0.65 microU/ml; 1800 h, 2.63 +/- 0.61 microU/ml and 2.64 +/- 1.21 microU/ml
1 context sentence(design, population, supporting numbers)
Summary · context
Oxytocin (OT) and the oxytocin-neurophysin (OT-Np) were measured by RIA in samples of cerebrospinal fluid (CSF) obtained sequentially at 0600, 1200, 1800, and 2400 h from six patients in whom intrathecal catheters were temporarily placed for CSF rhinorrhea.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926902
03HumanEndogenous levelObservational studyOther
In six patients with sequential cerebrospinal fluid sampling, endogenous oxytocin at 1200 h (6.41 +/- 1.13 and 5.06 +/- 0.58 microU/ml) was significantly higher (p less than 0.05) than at 2400 h (2.86 +/- 1.13 microU/ml).
In plain wordsIn six patients, the body's own oxytocin level in spinal fluid was higher at noon than at 2400 h.
Peptide
Oxytocin
Outcome
IncreaseCSF oxytocin concentration at 1200 h versus 2400 h
Study
n = 6
Comparator
2400 h
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
of OT at 1200 h, 6.41 +/- 1.13 microU/ml and 5.06 +/- 0.58 microU/ml, to be significantly higher (p less than 0.05) than mean levels of OT at 0600 h, 2.50 +/- 0.65 microU/ml; 1800 h, 2.63 +/- 0.61 microU/ml and 2.64 +/- 1.21 microU/ml; and 2400 h, 2.86 +/- 1.13 microU/ml
1 context sentence(design, population, supporting numbers)
Summary · context
Oxytocin (OT) and the oxytocin-neurophysin (OT-Np) were measured by RIA in samples of cerebrospinal fluid (CSF) obtained sequentially at 0600, 1200, 1800, and 2400 h from six patients in whom intrathecal catheters were temporarily placed for CSF rhinorrhea.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926903
04HumanEndogenous levelObservational studyOther
In six healthy men, endogenous plasma oxytocin showed no diurnal variation.
In plain wordsIn six healthy men, the body's own oxytocin in blood showed no daily variation.
Peptide
Oxytocin
Outcome
No significant changeDiurnal variation in plasma oxytocin
Study
n = 6
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
No diurnal variation of OT or its Np in the plasma of men or women was found.
1 context sentence(design, population, supporting numbers)
Summary · context
Levels of OT and OT-Np were measured by RIA of samples of plasma obtained hourly for a 24-h period from six healthy men and six healthy women.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926906
05HumanEndogenous levelObservational studyOther
In six healthy women, endogenous plasma oxytocin showed no diurnal variation.
In plain wordsIn six healthy women, the body's own oxytocin in blood showed no daily variation.
Peptide
Oxytocin
Outcome
No significant changeDiurnal variation in plasma oxytocin in women
Study
n = 6
Outcome group
Hormone levels · Endocrine and hormones
Source sentences
Summary
No diurnal variation of OT or its Np in the plasma of men or women was found.
1 context sentence(design, population, supporting numbers)
Summary · context
Levels of OT and OT-Np were measured by RIA of samples of plasma obtained hourly for a 24-h period from six healthy men and six healthy women.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926909
06HumanEndogenous levelObservational studyOther
In three patients with simultaneous samples, endogenous plasma oxytocin showed no peak corresponding to the cerebrospinal fluid peak.
In plain wordsIn three patients, the body's own oxytocin showed no matching peak in blood.
Peptide
Oxytocin
Outcome
No significant changePlasma oxytocin peak concurrent with CSF peak
Study
n = 3
Comparator
CSF oxytocin
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
In three of the patients simultaneous samples of blood were obtained for measurement of the same peptides, but no corresponding peak of OT or its Np was found in plasma of these three patients.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926904
07HumanEndogenous levelObservational studyOther
In three patients, endogenous oxytocin levels in cerebrospinal fluid were significantly higher than in plasma at all measured times.
In plain wordsIn three patients, the body's own oxytocin level was higher in spinal fluid than in blood.
Peptide
Oxytocin
Outcome
IncreaseCSF versus plasma oxytocin level
Study
n = 3
Comparator
Plasma oxytocin
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
The level of OT in CSF at all times was also significantly higher (p less than 0.05) than the level of OT in plasma of these three patients.
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-0661926905

Studies that did not test the peptide alone4

In this study, Oxytocin was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Oxytocin.

08HumanNot a test of Oxytocin aloneObservational studyOther
In six patients with sequential cerebrospinal fluid sampling, oxytocin-neurophysin levels in cerebrospinal fluid did not show a similar noon peak.
In plain wordsIn six patients, oxytocin-neurophysin in spinal fluid did not show a similar noon peak.
Peptide
Oxytocin
Outcome
Not applicableCerebrospinal fluid oxytocin-neurophysin peak
Study
n = 6
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
The levels of OT-Np in CSF did not show a similar peak.
2 context sentences(design, population, supporting numbers)
Summary · context
The highest levels of OT in CSF were found at 1200 h.
Summary · context
Oxytocin (OT) and the oxytocin-neurophysin (OT-Np) were measured by RIA in samples of cerebrospinal fluid (CSF) obtained sequentially at 0600, 1200, 1800, and 2400 h from six patients in whom intrathecal catheters were temporarily placed for CSF rhinorrhea.
In this study, Oxytocin was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Oxytocin.
Report a problemFND-0661926907
09HumanNot a test of Oxytocin aloneObservational studyOther
In six healthy men, plasma oxytocin-neurophysin showed no diurnal variation.
In plain wordsIn six healthy men, oxytocin-neurophysin in blood showed no daily variation.
Peptide
Oxytocin
Outcome
No significant changeDiurnal variation in plasma oxytocin-neurophysin in men
Study
n = 6
Outcome group
Hormone levels · Endocrine and hormones
Source sentences
Summary
No diurnal variation of OT or its Np in the plasma of men or women was found.
1 context sentence(design, population, supporting numbers)
Summary · context
Levels of OT and OT-Np were measured by RIA of samples of plasma obtained hourly for a 24-h period from six healthy men and six healthy women.
In this study, Oxytocin was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Oxytocin.
Report a problemFND-0661926910
10HumanNot a test of Oxytocin aloneObservational studyOther
In six healthy women, plasma oxytocin-neurophysin showed no diurnal variation.
In plain wordsIn six healthy women, oxytocin-neurophysin in blood showed no daily variation.
Peptide
Oxytocin
Outcome
No significant changeDiurnal variation in plasma oxytocin-neurophysin in women
Study
n = 6
Outcome group
Hormone levels · Endocrine and hormones
Source sentences
Summary
No diurnal variation of OT or its Np in the plasma of men or women was found.
1 context sentence(design, population, supporting numbers)
Summary · context
Levels of OT and OT-Np were measured by RIA of samples of plasma obtained hourly for a 24-h period from six healthy men and six healthy women.
In this study, Oxytocin was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Oxytocin.
Report a problemFND-0661926911
11HumanNot a test of Oxytocin aloneObservational studyOther
In three patients with simultaneous blood samples, no corresponding oxytocin-neurophysin peak was found in plasma.
In plain wordsIn three patients, oxytocin-neurophysin in blood showed no matching peak.
Peptide
Oxytocin
Outcome
Not applicablePlasma oxytocin-neurophysin peak
Study
n = 3
Outcome group
Hormone levels · Nervous system and cognition
Source sentences
Summary
In three of the patients simultaneous samples of blood were obtained for measurement of the same peptides, but no corresponding peak of OT or its Np was found in plasma of these three patients.
1 context sentence(design, population, supporting numbers)
Summary · context
Oxytocin (OT) and the oxytocin-neurophysin (OT-Np) were measured by RIA in samples of cerebrospinal fluid (CSF) obtained sequentially at 0600, 1200, 1800, and 2400 h from six patients in whom intrathecal catheters were temporarily placed for CSF rhinorrhea.
In this study, Oxytocin was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Oxytocin.
Report a problemFND-0661926908

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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.

Version 2Current
11 Oct 2026, 20:03 UTC
Study results updated
Version 1
9 Oct 2026, 02:53 UTC
First added · source update from Europe PMC

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