TY - JOUR
T1 - Opioid receptor binding to intact brain cells
AU - Rogers, N. F.
AU - El-Fakahany, E. E.
PY - 1985/1/1
Y1 - 1985/1/1
N2 - This model system was designed to investigate opioid receptor binding in a viable, intact cell system closely resembling in vivo cellular conditions. Cells were mechanically dissociated and sieved from adult rat brains, and iso-osmotic physiological buffer was used, thus avoiding mechanical and chemical disruption of cellular integrity due to homogenization or the use of non-physiological buffers, respectively. Using the opioid antagonist [3H]naloxone as the radioligand our studies show saturable binding, with a B(max) of 200.1 ± 6.3 fmoles/mg protein (mean ± SEM), and a K(d) of 1.38 ± 0.2 nM. Stereospecificity of [3H]naloxone binding to the intact cells, demonstrated by displacing the radioligand with the opioid agonist levorphanol and its inactive stereoisomer dextrorphan, yielded average K(i) values of 14.26 ± 2.42 nM and 16.37 ± 0.30 μM, respectively (n = 3). [3H]Naloxone binding was also linear over a wide range of tissue concentrations. This model will be useful for studying the binding of opioids or other classes of drugs to brain tissue in a relatively more physiologically relevant system.
AB - This model system was designed to investigate opioid receptor binding in a viable, intact cell system closely resembling in vivo cellular conditions. Cells were mechanically dissociated and sieved from adult rat brains, and iso-osmotic physiological buffer was used, thus avoiding mechanical and chemical disruption of cellular integrity due to homogenization or the use of non-physiological buffers, respectively. Using the opioid antagonist [3H]naloxone as the radioligand our studies show saturable binding, with a B(max) of 200.1 ± 6.3 fmoles/mg protein (mean ± SEM), and a K(d) of 1.38 ± 0.2 nM. Stereospecificity of [3H]naloxone binding to the intact cells, demonstrated by displacing the radioligand with the opioid agonist levorphanol and its inactive stereoisomer dextrorphan, yielded average K(i) values of 14.26 ± 2.42 nM and 16.37 ± 0.30 μM, respectively (n = 3). [3H]Naloxone binding was also linear over a wide range of tissue concentrations. This model will be useful for studying the binding of opioids or other classes of drugs to brain tissue in a relatively more physiologically relevant system.
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M3 - Article
AN - SCOPUS:0021868350
SN - 0014-9446
VL - 44
SP - No. 1165
JO - Federation Proceedings
JF - Federation Proceedings
IS - 3
ER -