Rats made nutritionally iron-deficient (ID) have been shown to have a lower brain non-haem. A selective diminution of the binding capacity of the D2-dopaminergic receptors alone was found among nutritionally iron-deficient rats. Peripherally administered β-endorphin significantly elevated the pain threshold only in the iron-deficient rats. Naloxone blocked the β-endorphin effect in ID rats. Morphine, as well as haloperidol, elevated the pain threshold in both the iron-deficient and the control rats but significantly more in the former group. No additive effects of combined treatment with β-endorphin and haloperidol on pain threshold were found. Other neuroleptics also elevated the pain threshold. A possible hypothesis is that dopamine (via β-endorphin) may play a role in modifying the pain threshold.
|Number of pages||7|
|Journal||European Journal of Pharmacology|
|State||Published - 17 Sep 1984|
Bibliographical noteFunding Information:
fl-Endorphin was generously donated by the N.I.H., U.S.A. This study was supported in part by research grants from the Bar-llan University Research Authority, by the Sapir Foundation and by the Rappaport Family Institute (Technion).
- Circadian rhythm