title: The distribution of radioligand binding activity and 5'-nucleotidase activity in bovine caudate nucleus subcellular fractions.
abstract: The distribution of 5'-nucleotidase activity, dopaminergic [3H]spiperone binding sites, and [3H]quinuclidinyl benzilate (QNB) binding sites in different subcellular fractions of bovine caudate nucleus has been studied. Each activity was enriched in a microsomal (P3) preparation from that tissue. The microsomal preparation was further fractionated by different techniques. First, the P3 fraction, or a sonicated P3 fraction, was fractionated on a discontinuous sucrose density gradient. Second, the P3 fraction, or a digitonin pretreated P3 fraction, was fractionated on a continuous sucrose density gradient. The results obtained demonstrate that 5'-nucleotidase activity does not cofractionate with radioligand binding activity, although no difference between the distributions of [3H]spiperone binding and [3H]QNB binding were seen. It is concluded that the two radioligand binding activities are located on nonglial membranes.
mesh_terms: D015720:5'-Nucleotidase; D000818:Animals; D002417:Cattle; D002421:Caudate Nucleus / Q000201:enzymology*; D004072:Digitonin / Q000494:pharmacology; D009708:Nucleotidases / Q000378:metabolism*; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011869:Radioligand Assay / Q000379:methods; D013134:Spiperone / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology; D014018:Tissue Distribution
chemical_list: D013134:Spiperone; D011813:Quinuclidinyl Benzilate; D009708:Nucleotidases; D015720:5'-Nucleotidase; D004072:Digitonin