2024-03-29T09:40:51Z
https://u-ryukyu.repo.nii.ac.jp/oai
oai:u-ryukyu.repo.nii.ac.jp:02015756
2022-10-31T07:43:53Z
1642838163960:1642838198944:1642838233003:1642838239325
1642838403551:1642838412624
[原著]ENHANCEMENT OF HEPATIC MICROSOMALAMINO・PYRINE N-DEMETHYLATION BY NEUTRAL SALTS
Aniya, Yoko
Matsusaki, Kichihiko
aminopyrine
N-demethylation
neutral salt
cytochrome P-450
Enhancement of aminopyrine N-demethylation by neutral salts was kinetically studied using hepatic microsomes from nontreated, phenobarbital- or 3-methylcholanthrene-treated rats. Aminopyrine N-demethylation was increased 3-fold by 0.4 M sodium sulfate in nontreated or 3-methylcholanthrene-treated microsomes. On the other hand, the enhancement was 1.7-fold in phenobarbital-treated microsomes. Lineweaver-Burk plots of aminopyrine N-demethylase were not linear in nontreated microsomes and two Km values (2X10^<-3>M, 5X10^<-4>M) were obtained. However, the addition of neutral salts to the microsomes brought on a linear Lineweaver-Burk plots of the demethylation and only one km, which was less than 2X10^<-3>M. Aminopyrine-induced difference spectra of the microsomes were increased by the addition of neutral salts, and double reciprocal plots of the spectrum vs aminopyrine concentration were linear, though the plots were not linear in absence of the salts. Dissociation constant (Ks) values were also decreased by the addition of neutral salts corresponding enhancement of the demethylation, as were the km values. In phenobarbital or 3-methylcholanthrene-treated microsomes one Km was obtained regardless of the presence or absence of sodium sulfate, though Km of the demethylase in the former microsomes was higher than that in the latter after addition of the salt. These results suggest that there are multiple forms of aminopyrine N-demethylase in nontreated and 3-methylcholanthrene -treated microsomes and some of them slightly contribute to the demethylation in normal condition but exhibite the demethylase activity by addition of the salts. Phenobarbital may induce the aminopyrine N-demethylase capable of demethylating aminopyrine in normal condition resulted in less enhancement of the demethylation by the salts.
論文
http://purl.org/coar/resource_type/c_6501
琉球大学医学部
Faculty of Medicine, University of the Ryukyus
1986
VoR
0289-1530
AN10027430
琉球大学医学会雑誌 : 医学部紀要 = Ryukyu medical journal
3-4
9
159
151
eng
open access
琉球医学会