Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 1978 Dec;64(4):607-14.
doi: 10.1111/j.1476-5381.1978.tb17323.x.

Comparison of the receptor binding characteristics of opiate agonists interacting with mu- or kappa-receptors

H W Kosterlitz, F M Leslie
Comparative Study

Comparison of the receptor binding characteristics of opiate agonists interacting with mu- or kappa-receptors

H W Kosterlitz et al. Br J Pharmacol. 1978 Dec.

Abstract

1 The receptor binding characteristics of various morphine-like and ketazocine-like opiate agonists were measured by inhibition of [3H]-naloxone binding in homogenates of brain and of ileal myenteric plexus-longitudinal muscle of the guinea-pig. No differences were found for the two tissues. 2 The depressant effect of Na+ on the inhibition of [3H]-naloxone binding by opiate agonists varies widely, giving sodium shifts between 5 and 140. The relationship between Na+ concentration and inhibition of binding is non-linear, the magnitude of the sodium shift varying directly with the slope of the regression of log IC50 on log [NaCl]. 3 The sodium shift of ketazocine-like agonists is lower than that of morphine-like agonists but higher than that of opiates with dual agonist and antagonist action. A working hypothesis is proposed which suggests that the kappa-receptors for the ketazocine-like drugs are less susceptible to the Na+ effect than the mu-receptors for the morphine-like drugs. 4 For most of the morphine-like but not the ketazocine-like agonists, a good correlation has been found for the pharmacological activity in the myenteric plexus-longitudinal muscle preparation and the inhibition of binding of [3H]-naloxone at 12 mM Na+. An exception is fentanyl which has a much greater pharmacological potency than may be expected from its potency in inhibiting [3H]-naloxone binding.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Br J Pharmacol Chemother. 1964 Apr;22:356-65 - PubMed
    1. Br J Pharmacol. 1970 Jun;39(2):398-413 - PubMed
    1. Br J Pharmacol. 1977 Mar;59(3):478P - PubMed
    1. J Pharmacol Exp Ther. 1975 Jul;194(1):205-19 - PubMed
    1. Br J Pharmacol Chemother. 1968 Jun;33(2):266-76 - PubMed

Publication types