Effects of detergents on binding of 5-hydroxytryptamine3 receptor antagonist [3H]GR65630 to rat cortical membranes.
In the absence of detergent, specific binding of [3H]GR65630, a 5-hydroxytryptamine3 (5-HT3) antagonist, determined in the presence of 5-HT3 receptor antagonist ICS205-930, was at most 30% of the total binding. To decrease the level of nonspecific binding, the effects of detergents on [3H]GR65630 binding to rat cortical membranes were investigated. The use of a detergent (0.1% Lubrol PX or Triton X-100) decreased nonspecific binding, increasing the proportion of specific binding to 70% of total binding. In the presence of 0.1% Triton X-100, binding of [3H]GR65630 was rapid, reversible and saturable at 25 degrees C. The rank order of 5-HT3 receptor active drugs in inhibiting [3H]GR65630 binding was quipazine > ICS205-930 > 2-methyl-5-HT = 5-HT > metoclopramide, which confirmed that [3H]GR65630 efficiently labeled 5-HT3 receptors in the presence of Triton X-100. Triton X-100 improved 5-HT3 receptor binding with rat brain membranes.
Department of Pharmacology, Hiroshima University School of Medicine, Japan.
A
A
Inoue
Y
Y
Tominaga
H
H
Nishio
T
T
Segawa
Y
Y
Nakata
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology*; D007093:Imidazoles / Q000378:metabolism*; D007211:Indoles / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism; D017830:Octoxynol; D000077423:Polidocanol; D011092:Polyethylene Glycols / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D012702:Serotonin Antagonists; D014316:Tritium
D003902:Detergents; D007093:Imidazoles; D007211:Indoles; D012702:Serotonin Antagonists; D003840:Deoxycholic Acid; D000077423:Polidocanol; D014316:Tritium; C059068:GR 65630; D011092:Polyethylene Glycols; D017830:Octoxynol