An increase in [3H]QNB binding by proton-beam irradiation in intact rat brain: an apparent positive cooperativity of binding.
After focal irradiation of rat brains with a beam of proton (dose, 30 Gy), [3H]quinuclidinyl benzilate (QNB) binding, both in vitro and in vivo, was measured, using either autoradiographic or tissue-dissection methods. No changes in in vitro [3H]QNB binding were seen in autoradiograms of brain slices from irradiated rat. The irradiated side of the brain showed a significant increase in [3H]QNB binding in vivo in the striatum and cerebral cortex 24 h after irradiation. This increase in binding was transient, and had almost disappeared 2 weeks after irradiation. These results indicate that early changes in receptor function as a results of radiation damage are only detected in in-vivo conditions. In the striatum of the intact rat brain, an apparent positive cooperativity of binding was observed, which was more pronounced on the irradiated side.
Inoue
O
O
School of Allied Health Sciences, Osaka University Faculty of Medicine, Japan. inoue@shahs.med.osa-u.ac.jp
Kobayashi
K
K
Takai
N
N
Furusawa
Y
Y
Ando
K
K
Nakano
T
T
Nishimura
T
T
D000818:Animals; D001921:Brain / Q000528:radiation effects*; D005720:Gamma Rays; D008297:Male; D011485:Protein Binding / Q000528:radiation effects; D011522:Protons; D011813:Quinuclidinyl Benzilate / Q000378:metabolism* / Q000528:radiation effects; D011849:Radioactive Tracers; D051381:Rats; D017208:Rats, Wistar; D014316:Tritium
D011522:Protons; D011849:Radioactive Tracers; D014316:Tritium; D011813:Quinuclidinyl Benzilate