文档介绍：185 Ρ
Ρ-85) Involvement of synthesis in supersensitivity of
a1-adrenoceptor-mediated contraction in rat vas deferens.
Hiroshi Higuchi, Masanobu Nakahiro* , Shuj i Uchida and Hiroshi
Yoshida. Departmnet of Pharmacology I, *Department of Psychi­
atry, Osaka University School of Medicine, Osaka 530, Japan.
When intact rat vas deferens was treated with an irreversible
antagonist, dibenamine, the decrease in maximum contraction to
NE was paralled to amount of a1-adrenoceptor. This indicated
the absence of spare α.-adrenoceptor in rat vas deferens.
During organ culture of rat vas deferens, the supersensiti­
vities of contraction to NE and ACh were observed, but that to
high K+ was not. The supersensitivities to NE were composed
of pre- and post-junctional supersensitivities. The post­
junctional supersensitivities through ax-adrenoceptor and
muscarinic receptor (c^-R, m-R) were not followed by quali­
tative or quantitative changes of a±-R and m-R, which were
measured with 3H-prazosin and 3H-QNB binding. The non­
selective post-junctional supersensitivity was blocked by low
temperature (4°C) and hypoxia. Especially the supersensitivity
to NE was inhibited significantly by inhibitors of protein
synthesis, puromycin or cycloheximide without changes in aj.-R
level. These findi