Characterization of [3H]-diprenorphine binding in Rana pipiens: Observations of filter binding enhanced by naltrexone

Leslie C. Newman, David Wallace, Craig Stevens

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Initial studies were undertaken to examine the properties of [3H]-diprenorphine binding to Rana pipiens whole brain tissue using naltrexone for the definition of nonspecific binding. Saturation analysis demonstrated the binding of [3H]-diprenorphine to be saturable with a K(D) value of 0.65 nM and a B(max) value of 287.7 fmol/mg protein. Unlabeled diprenorphine dose-dependently displaced [3H]-diprenorphine from a single noninteractive site in competition studies which yielded a K(i) of 0.22 nM. However, control studies in the absence of tissue revealed significant binding of [3H]-diprenorphine to the filter alone. Interestingly, [3H]-diprenorphine in the presence of unlabeled naltrexone as well as with unlabeled naloxone showed significantly greater binding to the filter than did [3H]-diprenorphine alone. Given this observation of increased nonspecific binding, an artificially low B(max) value would be expected. It is our hypothesis that the unlabeled nonspecific drug forms a complex with [3H]-diprenorphine preventing it from being effectively washed through the filter or the unlabeled drug itself is blocking the flow of [3H]-diprenorphine through the filter. The latter is unlikely however as other binding studies done in our lab using the radioligand [3H]-naloxone with unlabeled naltrexone do not show significant binding to the filter. Copyright (C) 1999 Elsevier Science Ltd.

Original languageEnglish
Pages (from-to)43-48
Number of pages6
JournalJournal of Pharmacological and Toxicological Methods
Volume41
Issue number1
DOIs
StatePublished - 1 Feb 1999

Fingerprint

Diprenorphine
Rana pipiens
Naltrexone
Naloxone
Tissue
Pharmaceutical Preparations
Brain

Keywords

  • Naltrexone
  • Rana pipiens
  • [H]-Diprenorphine

Cite this

@article{d912d17a480240c4b2a48ca059a39b4b,
title = "Characterization of [3H]-diprenorphine binding in Rana pipiens: Observations of filter binding enhanced by naltrexone",
abstract = "Initial studies were undertaken to examine the properties of [3H]-diprenorphine binding to Rana pipiens whole brain tissue using naltrexone for the definition of nonspecific binding. Saturation analysis demonstrated the binding of [3H]-diprenorphine to be saturable with a K(D) value of 0.65 nM and a B(max) value of 287.7 fmol/mg protein. Unlabeled diprenorphine dose-dependently displaced [3H]-diprenorphine from a single noninteractive site in competition studies which yielded a K(i) of 0.22 nM. However, control studies in the absence of tissue revealed significant binding of [3H]-diprenorphine to the filter alone. Interestingly, [3H]-diprenorphine in the presence of unlabeled naltrexone as well as with unlabeled naloxone showed significantly greater binding to the filter than did [3H]-diprenorphine alone. Given this observation of increased nonspecific binding, an artificially low B(max) value would be expected. It is our hypothesis that the unlabeled nonspecific drug forms a complex with [3H]-diprenorphine preventing it from being effectively washed through the filter or the unlabeled drug itself is blocking the flow of [3H]-diprenorphine through the filter. The latter is unlikely however as other binding studies done in our lab using the radioligand [3H]-naloxone with unlabeled naltrexone do not show significant binding to the filter. Copyright (C) 1999 Elsevier Science Ltd.",
keywords = "Naltrexone, Rana pipiens, [H]-Diprenorphine",
author = "Newman, {Leslie C.} and David Wallace and Craig Stevens",
year = "1999",
month = "2",
day = "1",
doi = "10.1016/S1056-8719(99)00020-9",
language = "English",
volume = "41",
pages = "43--48",
journal = "Journal of Pharmacological and Toxicological Methods",
issn = "1056-8719",
publisher = "Elsevier Inc.",
number = "1",

}

TY - JOUR

T1 - Characterization of [3H]-diprenorphine binding in Rana pipiens

T2 - Observations of filter binding enhanced by naltrexone

AU - Newman, Leslie C.

AU - Wallace, David

AU - Stevens, Craig

PY - 1999/2/1

Y1 - 1999/2/1

N2 - Initial studies were undertaken to examine the properties of [3H]-diprenorphine binding to Rana pipiens whole brain tissue using naltrexone for the definition of nonspecific binding. Saturation analysis demonstrated the binding of [3H]-diprenorphine to be saturable with a K(D) value of 0.65 nM and a B(max) value of 287.7 fmol/mg protein. Unlabeled diprenorphine dose-dependently displaced [3H]-diprenorphine from a single noninteractive site in competition studies which yielded a K(i) of 0.22 nM. However, control studies in the absence of tissue revealed significant binding of [3H]-diprenorphine to the filter alone. Interestingly, [3H]-diprenorphine in the presence of unlabeled naltrexone as well as with unlabeled naloxone showed significantly greater binding to the filter than did [3H]-diprenorphine alone. Given this observation of increased nonspecific binding, an artificially low B(max) value would be expected. It is our hypothesis that the unlabeled nonspecific drug forms a complex with [3H]-diprenorphine preventing it from being effectively washed through the filter or the unlabeled drug itself is blocking the flow of [3H]-diprenorphine through the filter. The latter is unlikely however as other binding studies done in our lab using the radioligand [3H]-naloxone with unlabeled naltrexone do not show significant binding to the filter. Copyright (C) 1999 Elsevier Science Ltd.

AB - Initial studies were undertaken to examine the properties of [3H]-diprenorphine binding to Rana pipiens whole brain tissue using naltrexone for the definition of nonspecific binding. Saturation analysis demonstrated the binding of [3H]-diprenorphine to be saturable with a K(D) value of 0.65 nM and a B(max) value of 287.7 fmol/mg protein. Unlabeled diprenorphine dose-dependently displaced [3H]-diprenorphine from a single noninteractive site in competition studies which yielded a K(i) of 0.22 nM. However, control studies in the absence of tissue revealed significant binding of [3H]-diprenorphine to the filter alone. Interestingly, [3H]-diprenorphine in the presence of unlabeled naltrexone as well as with unlabeled naloxone showed significantly greater binding to the filter than did [3H]-diprenorphine alone. Given this observation of increased nonspecific binding, an artificially low B(max) value would be expected. It is our hypothesis that the unlabeled nonspecific drug forms a complex with [3H]-diprenorphine preventing it from being effectively washed through the filter or the unlabeled drug itself is blocking the flow of [3H]-diprenorphine through the filter. The latter is unlikely however as other binding studies done in our lab using the radioligand [3H]-naloxone with unlabeled naltrexone do not show significant binding to the filter. Copyright (C) 1999 Elsevier Science Ltd.

KW - Naltrexone

KW - Rana pipiens

KW - [H]-Diprenorphine

UR - http://www.scopus.com/inward/record.url?scp=0032587540&partnerID=8YFLogxK

U2 - 10.1016/S1056-8719(99)00020-9

DO - 10.1016/S1056-8719(99)00020-9

M3 - Article

C2 - 10507757

AN - SCOPUS:0032587540

VL - 41

SP - 43

EP - 48

JO - Journal of Pharmacological and Toxicological Methods

JF - Journal of Pharmacological and Toxicological Methods

SN - 1056-8719

IS - 1

ER -