Abstract
The spin-label antibody technique has been adapted to the determination of serum morphine concentrations. Our results indicate that with a 0.30-ml solution cell, the ultimate sensitivity of the assay is 35 nM (10 ng of morphine per ml) which is very close to the instrumental detection limit for spin-labeled morphine of 20 nM (5.7 ng/ml). Comparison of t½'S for disappearance of [N-methyl/-14C]morphine in a rabbit yielded 1.9 hr by 14C counting and 1.6 hr by the spin-label technique. Serum binding of morphine can be easily and rapidly determined utilizing the spin-labeled drug; the percentage of free (unbound) morphine in human serum was found to be 69.5± 0.9% by the spin-label technique and 64.6 ± 1.4% by ultrafiltration. Our results would suggest that this method holds promise for the assay of serum concentrations and binding not only of morphine but of other drugs as well.
Footnotes
- Received March 8, 1974.
- Copyright © 1974 by The American Society for Pharmacology and Experimental Therapeutics
DMD 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.
|