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Study · Animal study (in vivo) · macaca mulatta · 1987

18 results

Reversibility of long-term effects of GnRH agonist administration on testicular histology and sperm production in the nonhuman primate.

Weinbauer GF, Respondek M, Themann H, Nieschlag E

Journal of andrology1 Sept 1987Cited by 11 (Europe PMC)

PMID2959641 (opens in a new tab)DOI10.1002/j.1939-4640.1987.tb00970.x (opens in a new tab)PepBankPUB-02959641
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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 study18

18 results from studies that gave the peptide. No result from this study comes from people.

  1. 01AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, nafarelin-loaded microspheres uniformly suppressed serum bioactive LH.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres suppressed blood LH.

    Peptide
    Nafarelin
    Outcome
    DecreaseBioactive LH
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Monthly injection of the GnRH agonist preparation uniformly suppressed serum levels of bioactive LH and testosterone.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  2. 02AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, nafarelin-loaded microspheres uniformly suppressed serum testosterone.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres suppressed testosterone.

    Peptide
    Nafarelin
    Outcome
    DecreaseTestosterone
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Monthly injection of the GnRH agonist preparation uniformly suppressed serum levels of bioactive LH and testosterone.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  3. 03AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, nafarelin-loaded microspheres reduced testis size to about 30% of pretreatment size.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres reduced testis size to about 30% of its initial size.

    Peptide
    Nafarelin
    Outcome
    DecreaseTestis size
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    The size of the testis was reduced to about 30% of pretreatment.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  4. 04AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys, seminiferous tubule diameter decreased after 6, 12 and 20 months of nafarelin-loaded microspheres versus pretreatment histology.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres decreased testicular tubule diameter compared with pretreatment histology.

    Peptide
    Nafarelin
    Outcome
    DecreaseSeminiferous tubule diameter
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Evaluation of testicular biopsy material after 6, 12 and 20 months of treatment revealed decreased seminiferous tubule diameter
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  5. 05AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys, nafarelin-loaded microspheres increased tubular wall thickness through enlargement of the inner collagen layer.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres increased the inner collagen layer of testicular tubules.

    Peptide
    Nafarelin
    Outcome
    IncreaseInner collagen layer
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Electron microscopic examination revealed that the increased wall thickness was due to an enlargement of the inner collagen layer.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  6. 06AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys given nafarelin-loaded microspheres, no fibrosis was detected.

    In plain wordsIn rhesus monkeys given nafarelin-loaded microspheres, no fibrosis was detected.

    Peptide
    Nafarelin
    Outcome
    Not applicableFibrosis
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    No evidence of fibrosis or calcification could be obtained.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  7. 07AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys given nafarelin-loaded microspheres, no calcification was detected.

    In plain wordsIn rhesus monkeys given nafarelin-loaded microspheres, no calcification was detected.

    Peptide
    Nafarelin
    Outcome
    Not applicableCalcification
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    No evidence of fibrosis or calcification could be obtained.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  8. 08AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys given nafarelin-loaded microspheres, Leydig cells were atrophic.

    In plain wordsIn rhesus monkeys given nafarelin-loaded microspheres, testosterone-producing cells shrank.

    Peptide
    Nafarelin
    Outcome
    Not applicableLeydig cell atrophy
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Leydig cells were atrophic.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  9. 09AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, serum hormones returned to pretreatment values within 5 to 8 weeks after nafarelin-loaded microsphere treatment ended.

    In plain wordsIn rhesus monkeys, hormones returned to initial values within 5 to 8 weeks after nafarelin-loaded microsphere treatment ended.

    Peptide
    Nafarelin
    Outcome
    No significant changeSerum hormone recovery
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Serum hormones, testis size and sperm counts returned to pretreatment values within 5 to 8, 13 to 16, and 18 weeks, respectively, after termination of treatment.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  10. 10AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, testis size returned to pretreatment values within 13 to 16 weeks after nafarelin-loaded microsphere treatment ended.

    In plain wordsIn rhesus monkeys, testis size returned to initial values within 13 to 16 weeks after nafarelin-loaded microsphere treatment ended.

    Peptide
    Nafarelin
    Outcome
    No significant changeTestis size recovery
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Serum hormones, testis size and sperm counts returned to pretreatment values within 5 to 8, 13 to 16, and 18 weeks, respectively, after termination of treatment.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  11. 11AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, sperm counts returned to pretreatment values within 18 weeks after nafarelin-loaded microsphere treatment ended.

    In plain wordsIn rhesus monkeys, sperm counts returned to initial values within 18 weeks after nafarelin-loaded microsphere treatment ended.

    Peptide
    Nafarelin
    Outcome
    No significant changeSperm count recovery
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Serum hormones, testis size and sperm counts returned to pretreatment values within 5 to 8, 13 to 16, and 18 weeks, respectively, after termination of treatment.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  12. 12AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, testicular histology was indistinguishable from pretreatment 8 months after nafarelin-loaded microsphere treatment ended.

    In plain wordsIn rhesus monkeys, testicular tissue resembled initial tissue 8 months after nafarelin-loaded microsphere treatment ended.

    Peptide
    Nafarelin
    Outcome
    No significant changeTesticular histology recovery
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Testicular histology, assessed 8 months after cessation of treatment, was indistinguishable from pretreatment.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  13. 13AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys, nafarelin-loaded microspheres disrupted spermatogenesis at the spermatogonia or spermatocyte stage versus pretreatment histology.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres disrupted sperm development compared with pretreatment histology.

    Peptide
    Nafarelin
    Outcome
    Not applicableSpermatogenic disruption
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment histology
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 6, 12 and 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    spermatogenic disruption at the level of spermatogonia or spermatocytes, accumulation of lipid droplets and secondary lysosomes in the Sertoli cell cytoplasm, and increased thickness of the tubular wall compared with pretreatment histology.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  14. 14AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys, lipid droplets accumulated in Sertoli cells during nafarelin-loaded microsphere treatment versus pretreatment histology.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres increased lipid droplets in testicular Sertoli cells compared with pretreatment histology.

    Peptide
    Nafarelin
    Outcome
    IncreaseSertoli cell lipid droplets
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment histology
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 6, 12 and 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    accumulation of lipid droplets and secondary lysosomes in the Sertoli cell cytoplasm, and increased thickness of the tubular wall compared with pretreatment histology.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  15. 15AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys, secondary lysosomes accumulated in Sertoli cells during nafarelin-loaded microsphere treatment versus pretreatment histology.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres increased secondary lysosomes in testicular Sertoli cells compared with pretreatment histology.

    Peptide
    Nafarelin
    Outcome
    IncreaseSertoli cell secondary lysosomes
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment histology
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 6, 12 and 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    accumulation of lipid droplets and secondary lysosomes in the Sertoli cell cytoplasm, and increased thickness of the tubular wall compared with pretreatment histology.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  16. 16AnimalAnimal study (in vivo)Safety outcome

    In rhesus monkeys, nafarelin-loaded microspheres increased tubular wall thickness compared with pretreatment histology.

    In plain wordsIn rhesus monkeys, nafarelin-loaded microspheres thickened testicular tubule walls compared with pretreatment histology.

    Peptide
    Nafarelin
    Outcome
    IncreaseTubular wall thickness
    Study

    Macaca mulattan = 4

    Adult rhesus monkeys
    Comparator
    Pretreatment histology
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 6, 12 and 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    increased thickness of the tubular wall compared with pretreatment histology.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  17. 17AnimalAnimal study (in vivo)Efficacy outcome

    In rhesus monkeys, nafarelin-loaded microspheres suppressed sperm counts to azoospermia for 53 and 77 weeks in two animals.

    In plain wordsIn two rhesus monkeys, nafarelin-loaded microspheres reduced semen sperm counts to zero for 53 and 77 weeks.

    Peptide
    Nafarelin
    Outcome
    DecreaseAzoospermia
    Study

    Macaca mulattan = 2

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Sperm counts were suppressed to azoospermia for a total period of 53 and 77 weeks, respectively, in two monkeys and the other two animals were extremely oligozoospermic.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.
  18. 18AnimalAnimal study (in vivo)Efficacy outcome

    In the other two rhesus monkeys, nafarelin-loaded microspheres produced extreme oligozoospermia.

    In plain wordsIn two rhesus monkeys, nafarelin-loaded microspheres greatly reduced sperm counts.

    Peptide
    Nafarelin
    Outcome
    DecreaseOligozoospermia
    Study

    Macaca mulattan = 2

    Adult rhesus monkeys
    Comparator
    Pretreatment
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    Dose not stated · intramuscular microspheres · 20 monthsAs given in this study (Macaca mulatta).

    Source sentences

    Summary
    Sperm counts were suppressed to azoospermia for a total period of 53 and 77 weeks, respectively, in two monkeys and the other two animals were extremely oligozoospermic.
    1 context sentence
    Summary · context
    Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months.

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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.

  1. Version 2Current

    28 Oct 2026, 02:03 UTC

    Study results updated

  2. Version 1

    27 Oct 2026, 16:36 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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