Loss of D1 and D2 dopamine receptors and muscarinic cholinergic receptors in rat brain following in vitro polytron homogenization.
The receptor specific binding of [3H]SCH23390 and [3H]spiperone to rat striatal membranes and [3H]QNB to rat cortical membranes was significantly reduced if the membrane suspensions were subjected to polytron homogenization. The degree of loss of the binding sites was a function of the polytron speed (setting) and the length of time of homogenization. Although the loss of binding sites could be reduced by maintaining a cold temperature of the tissue suspension during polytron homogenization, significant loss of binding sites could not be prevented. As many as 75% of the binding sites could be lost following polytron homogenization under the conditions employed in the present experiments. However, no significant change in the affinity of the remaining binding sites was observed. The loss of binding sites is not likely due to small tissue fragments passing through the filters. Care should be taken during tissue homogenization using a polytron or similar equipment to ensure that loss of receptor binding sites is minimized or remains constant between individual samples.
Norman
A B
AB
Department of Psychiatry, University of Cincinnati College of Medicine, OH 45267-0559.
Borchers
M T
MT
Wachendorf
T J
TJ
Price
A L
AL
Sanberg
P R
PR
D000818:Animals; D001552:Benzazepines / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D008297:Male; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism*
D001552:Benzazepines; D011954:Receptors, Dopamine; D011976:Receptors, Muscarinic; D013134:Spiperone; D011813:Quinuclidinyl Benzilate