ArticleProceedings of the National Academy of Sciences of the United States of America1990
Proenkephalin products are stored in the sperm acrosome and may function in fertilization.
Article in Proceedings of the National Academy of Sciences of the United States of America, 1990. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
10 citing papers in PubMed, 51 citations in OpenAlex.
- The impact of supplementation with calcium and naloxone to TRIS and Lepus extenders on the quality of refrigerated rabbit semen.Frontiers in veterinary science · 2026Article
- Article
- Opioid-Induced Androgen Deficiency (OPIAD): Diagnosis, Management, and Literature Review.Current urology reports · 2016Review
- Regulation of male fertility by the opioid system.Molecular medicine (Cambridge, Mass.) · 2011Review
- Delta opioid receptor on equine sperm cells: subcellular localization and involvement in sperm motility analyzed by computer assisted sperm analyzer (CASA).Reproductive biology and endocrinology : RB&E · 2010Article
- Reduced fertility in male mice deficient in the zinc metallopeptidase NL1.Molecular and cellular biology · 2004Article
- Molecular cloning and biochemical characterization of a new mouse testis soluble-zinc-metallopeptidase of the neprilysin family.The Biochemical journal · 2000Article
- Cleavage of arginyl-arginine and lysyl-arginine from the C-terminus of pro-hormone peptides by human germinal angiotensin I-converting enzyme (ACE) and the C-domain of human somatic ACE.The Biochemical journal · 1997Article
- Impaired fertility in mice deficient for the testicular germ-cell protease PC4.Proceedings of the National Academy of Sciences of the United States of America · 1997Article
- Fibroblast growth factor and cyclic AMP (cAMP) synergistically activate gene expression at a cAMP response element.Molecular and cellular biology · 1994Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
Previous studies have shown that spermatogenic cells are a major source of testicular RNA encoding the opioid peptide precursor proenkephalin, suggesting that proenkephalin-derived peptides may function as intratesticular paracrine factors produced by male germ cells. However, direct evidence for the production of proenkephalin by spermatogenic cells has been lacking. In this report, we have used polysome profile analysis, peptide quantitation, and immunocytochemistry to show that proenkephalin products are synthesized during spermatogenesis and are retained within spermatozoa of humans, hamsters, rats, and sheep. We further show that these peptides are stored in the sperm acrosome and are depleted from sperm following the acrosome reaction, an exocytotic event required for fertilization. Proenkephalin products thus may serve a dual function as sperm acrosomal factors released during the fertilization process as well as intratesticular regulators secreted by spermatogenic cells.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.