This record provides bibliographic details and links to the original research. An editorial study breakdown is not available.
What the researchers found
Loss of beta-endorphin and/or proenkephalin caused differential, region-specific, and sex-specific modulation of mu, delta, and kappa opioid receptor expression and activity, with no compensatory increase in dynorphin-derived peptides.
Why it matters
Opioid receptors are major drug targets for pain, addiction, and mood. Knowing that the body's own opioid peptides regulate these receptors helps explain individual differences in pain sensitivity and addiction vulnerability.
The numbers in context
3 knockout types; mu/delta/kappa all affected; region-specific; sex-specific; Leu-enkephalin mainly from proenkephalin; no dynorphin compensation
How the study worked
Knockout mouse study. Mice lacking proenkephalin, beta-endorphin, or both were compared to wild-type. Leu-enkephalin and dynorphin levels measured by mass spectrometry. Opioid receptor levels and G-protein activity measured in specific brain regions. Males and females compared.
Who was studied
C57BL mice lacking proenkephalin, beta-endorphin, or both vs wild-type
What this study cannot tell us
Mouse knockout study. Complete absence of a peptide from birth does not mimic natural human variation. Compensatory developmental changes may mask acute effects. Cannot directly extrapolate sex differences to humans.
Read the original research
Regulation of Opioid Receptors by Their Endogenous Opioid Peptides.
Cellular and molecular neurobiology, 41(5), 1103-1118
Citation
Gupta, Achla; Gullapalli, Srinivas; Pan, Hui; Ramos-Ortolaza, Dinah L; Hayward, Michael D; Low, Malcom J; Pintar, John E; Devi, Lakshmi A; Gomes, Ivone. (2021). Regulation of Opioid Receptors by Their Endogenous Opioid Peptides.. Cellular and molecular neurobiology, 41(5), 1103-1118. https://doi.org/10.1007/s10571-020-01015-w