A comparative study of the conversion of 7-hydroxycholesterol in rabbit, guinea pig, rat, hamster, and chicken.
The metabolism of epimeric 7-hydroxycholesterol was studied in vitro. 7Alpha-hydroxycholesterol or 7beta-hydroxycholesterol were incubated with rabbit, guinea pig, rat, hamster, and chicken microsomal suspensions and then extracted and analyzed using high-performance liquid chromatography (HPLC). 7Alpha-hydroxy-4-cholesten-3-one was the main product from 7alpha-hydroxycholesterol in the rabbit, guinea pig, and rat. A considerable amount of 7-ketocholesterol was also produced in the hamster and chicken. In all vertebrates, 7beta-hydroxycholesterol was converted only to 7-ketocholesterol in all vertebrates. 7Beta-hydroxy-4-cholesten-3-one was not detected. Reduction of 7-ketocholesterol was also studied in the rat and hamster. Whereas 7-ketocholesterol was converted to 7beta-hydroxycholesterol in the rat, it was converted to both 7alpha- and 7beta-hydroxycholesterol in the hamster. These results suggest that 7alpha-hydroxycholesterol is converted not only to 7alpha-hydroxy-4-cholesten-3-one but also to 7-ketocholesterol in the hamster and chicken. 7Beta-hydroxycholesterol was converted to 7-ketocholesterol in all vertebrates tested. The interconversion between 7alpha- and 7beta-hydroxycholesterol via 7-ketocholesterol was observed in the hamster in this in vitro study.
Maeda
Yorio
Y
Department of Surgery I, Miyazaki Medical College, 5200 Kihara, Kiyotake, Miyazaki, Japan. maedayo@post.miyazaki-med.ac.jp
Nagatomo
Hidehito
H
Uchiyama
Fujio
F
Nagatomo
Junji
J
Yamada
Manabu
M
Shiotsuki
Hironori
H
Ohta
Yoshikazu
Y
Sato
Shingo
S
Kai
Masa-Hiro
MH
Kondo
Kazu-Hiro
KH
Higashi
Shushi
S
Setoguchi
Toshiaki
T
D000818:Animals; D002645:Chickens / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006224:Cricetinae; D005260:Female; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D006888:Hydroxycholesterols / Q000737:chemistry / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism; D008297:Male; D008647:Mesocricetus / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D014020:Tissue Extracts
D006888:Hydroxycholesterols; D014020:Tissue Extracts