Abstract
A crude membrane fraction (CMF) from rat brain is labeled with [3H]etorphine (2 x 10-9 M) in the absence (total binding, -L) and in the presence (nonspecific binding, +L) of 2 x 10-6 M levorphanol. The 3H-labeled CMF (±L) is solubilized with 1% (w/v) cholic acid (sodium salt) and centrifuged. The high-speed (100,000 x g) supernatant is analyzed by molecular exclusion chromatography on Sephadex G-25, Sephadex G-100, and Sepharose 6B. A comparison of the radioactivity profiles reveals, in addition to the previously identified 500,000 mol wt species [Puget et al., F. E. B. S. Lett. 122:199-202 (1980)] lower molecular weight, tritium-labeled entities distinct from monomolecular [3H]etorphine. These small complexes are readily separated from free radioligand upon dialysis in the cold. They appear to be opiate-specific, since they are not observed in 3H-labeled CMF (+L) soluble extracts.
- Copyright © 1981 by The American Society for Pharmacology and Experimental Therapeutics
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|
Log in using your username and password
Purchase access
In this issue
Opiate Receptors in the Rat Brain
