Agonist-antagonist properties of fluorescent opioid probes in the guinea-pig myenteric plexus-longitudinal muscle preparation.
AuthorsKoman A, Einarsson M, Terenius L
JournalNaunyn Schmiedebergs Arch Pharmacol
PubMed ID2419770
'The opioid activity of a series of fluorescent derivatives of oxymorphone, naloxone and naltrexone, were characterized on the electrically stimulated guinea-pig myenteric plexus-longitudinal muscle preparation. In all compounds the fluorescent moiety, fluorescein or tetramethylrhodamine B, is attached to the C-6 carbon of the morphinan. Mu-receptor affinity was well retained and ... More
Fluorescein-labeled naloxone binding to mu opioid receptors on live Chinese hamster ovary cells using confocal fluorescent microscopy.
AuthorsMadsen BW, Beglan CL, Spivak CE
JournalJ Neurosci Methods
PubMed ID10788666
'A general method of confocal laser scanning microscopy was used to demonstrate specific binding of fluorescein-labeled naloxone (FNAL, 10-50 nM) to stably transfected mu opioid receptors on live Chinese hamster ovary cells. Nonspecific binding was visually indistinguishable from autofluorescence in cells with intact cell membranes. Fluorescent labeling of cell perimeters, ... More
Fluorescent probes for opioid receptors.
AuthorsKolb VM, Koman A, Terenius L
JournalLife Sci
PubMed ID6319896
Naloxone, naltrexone and oxymorphone were labeled in position 6 with fluorescein by coupling their hydrazone analogs with fluorescein isothiocyanate. Naloxone was also coupled in a similar way with rhodamine-B. The compounds thus obtained were: "6-FN", [1-(N)-fluoresceinyl naloxone thiosemicarbazone]; "6-FNX", [1-(N)-fluoresceinyl naltrexone thiosemicarbazone]; "6-FO", [1-(N)-fluoresceinyl oxymorphone thiosemicarbazone]; "6-RN", [1-(N)-tetramethylrhodaminyl-B naloxone thiosemicarbazone]. ... More
Changes in opioid receptor density on murine splenocytes induced by in vivo treatment with morphine and methadone.
AuthorsPatrini G, Massi P, Ricevuti G, Mazzone A, Fossati G, Mazzucchelli I, Gori E, Parolaro D
JournalJ Pharmacol Exp Ther
PubMed ID8858990
In a 24-hr time course study we reported previously that a single systemic injection of morphine profoundly affected various immune parameters in mice. In the present study we examined whether these effects are mediated by changes in opioid receptor density on murine splenocytes after acute in vivo morphine (20 mg/kg ... More
Increased opioid binding to peripheral white blood cells in a rat model of acute cholestasis.
BACKGROUND/AIMS: Endogenous opioids accumulate in plasma in cholestasis. Furthermore, immune cells have opioid receptors, and endogenous opioids have immunomodulatory effects. This study examined the expression of opioid receptors on peripheral white blood cells in rats with acute cholestasis after bile duct resection (BDR). METHODS: Five days after surgery, white blood ... More
Alterations in the visual cortex receptor pattern by operant conditioning in a reward paradigm.
AuthorsLöhrke B, Franz H, Brose R, Klein M
JournalBiol Chem Hoppe Seyler
PubMed ID7576247
The aim of the study was to investigate the impact of operant conditioning on the receptor pattern in the visual cortex of calves. A reward paradigm was used to induce conditioned preference for colours. Binding sites in visual cortex specimens from conditioned and naive animals were assayed in vitro on ... More