Beta-casomorphin-5 stimulates neurite outgrowth in a mouse neuroblastoma cell line (Neuro-2a).
We studied the effect of beta-casomorphin-5 (mu-acting opioid peptides derived from milk protein beta-casein) on neurite outgrowth of mouse neuroblastoma cell line, Neuro-2a. Beta-casomorphin-5 stimulated neurite outgrowth of Neuro-2a cells in a naloxone-reversible manner. The stimulating effect of beta-casomorphin-5 was observed even at picomolar concentrations. The selective mu-agonist, (D-Ala2, N-Me-Phe4, Gly5-ol)-enkephalin (DAMGO) exhibited the similar stimulating effect only at micromolar concentrations. On the other hand, (D-Pen(2,5))-enkephalin (DPDPE) (a delta-agonist), U-50,488 (a kappa-agonist), and endogenous opioid peptides, such as enkephalins and dynorphin A (1-13), showed no such stimulating effect. These results suggest that the neurite outgrowth-stimulating action of beta-casomorphin-5 may be mediated via a receptor which has mu-like characteristics and high sensitivity to beta-casomorphin-5, and that beta-casomorphins may play a role as a neurite elongation factor during the suckling period.
Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, Takatsuki, Japan.
M
M
Sakaguchi
K
K
Murayama
K
K
Yabe
M
M
Satoh
M
M
Takeuchi
E
E
Matsumura
D000818:Animals; D002364:Caseins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004723:Endorphins / Q000494:pharmacology*; D006133:Growth Substances / Q000494:pharmacology*; D051379:Mice; D016501:Neurites / Q000187:drug effects* / Q000502:physiology*; D009447:Neuroblastoma / Q000473:pathology*; D010446:Peptide Fragments / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D002364:Caseins; D004723:Endorphins; D006133:Growth Substances; D010446:Peptide Fragments; C034812:beta-casomorphin 5