TY - JOUR
T1 - Binding capacities and affinities AT μ ∂ and k-opioid sites in membrane suspensions from Guinea-pig brain regions
AU - Regina, Antonio La
AU - Colombo, Monica
AU - Petrillo, Paola
AU - Tavani, Alessandra
PY - 1992
Y1 - 1992
N2 - Binding capacities and affinities (KD) of ligands at μ ∂ and k-opioid binding sites were determined by selective labelling techniques together with analysis of saturation curves in seven regions of the guinea-pig brain. The k-sites predominated over the other sites in most regions and were 90% of the total in the cerebellum; binding capacities at ∂sites were highest in the cortex, intermediate in the cerebellum, striatum and mesencephalon and lowest in the diencephalon, hippocampus and pons-medulla. At the μsites, binding capacities were highest in the diencephalon and mesencephalon, with intermediate levels in the pons-medulla, cortex and striatum, and low levels in the hippocampus and cerebellum. The highest binding capacity at the ∂sites was in the striatum, intermediate in the cortex, diencephalon and hippocampus, low in the mesencephalon and pons-medulla and not detectable in the cerebellum. No regional differences in binding affinities were found at μ ∂ and k-sites with [3H]-[D-Ala2, MePhe4, Gly-ol5]enkephalin (KD = 1.10-2,61 nM), [3H]-[D-Ala2, D-Leu5]enkephalin (KD = 0.81-1.94 nM) and [3H]-(-)-bremazocine (KD = 0.083-0.185 nM). Thus in guinea-pig brain there are regional differences in opioid binding capacity and in the distribution of μ ∂ and k-sites, but not in binding affinities.
AB - Binding capacities and affinities (KD) of ligands at μ ∂ and k-opioid binding sites were determined by selective labelling techniques together with analysis of saturation curves in seven regions of the guinea-pig brain. The k-sites predominated over the other sites in most regions and were 90% of the total in the cerebellum; binding capacities at ∂sites were highest in the cortex, intermediate in the cerebellum, striatum and mesencephalon and lowest in the diencephalon, hippocampus and pons-medulla. At the μsites, binding capacities were highest in the diencephalon and mesencephalon, with intermediate levels in the pons-medulla, cortex and striatum, and low levels in the hippocampus and cerebellum. The highest binding capacity at the ∂sites was in the striatum, intermediate in the cortex, diencephalon and hippocampus, low in the mesencephalon and pons-medulla and not detectable in the cerebellum. No regional differences in binding affinities were found at μ ∂ and k-sites with [3H]-[D-Ala2, MePhe4, Gly-ol5]enkephalin (KD = 1.10-2,61 nM), [3H]-[D-Ala2, D-Leu5]enkephalin (KD = 0.81-1.94 nM) and [3H]-(-)-bremazocine (KD = 0.083-0.185 nM). Thus in guinea-pig brain there are regional differences in opioid binding capacity and in the distribution of μ ∂ and k-sites, but not in binding affinities.
KW - Binding affinities
KW - Binding capacities
KW - Brain regions
KW - Guinea-pig
KW - Opioids
KW - μpart;and k-opioid binding sites
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U2 - 10.3109/10799899209074790
DO - 10.3109/10799899209074790
M3 - Article
C2 - 1316438
AN - SCOPUS:0026522628
VL - 12
SP - 171
EP - 180
JO - Journal of Receptor and Signal Transduction Research
JF - Journal of Receptor and Signal Transduction Research
SN - 1079-9893
IS - 2
ER -