Changes in immunohistochemical distribution of cytochrome MC-P-448 in the rat liver during acclimation to cold.
Immunohistochemical localization of cytochrome MC-P-448 (form of cytochrome P-450 induced by methylcholanthrene) in rat hepatic lobule and the changes in their distribution pattern in response to cold exposure at 4 degrees C were investigated. The distribution of hepatocytes expressing immunoreactivity to cytochrome MC-P-448 was demonstrated with rabbit anti-MC-P-448 serum using a microphotomeasurment system P1 (Nikon). A duration of cold exposure for 1, 2, 3 or 4 weeks at 4 degrees C was applied to study the effect of cold adaptation of cytochrome MC-P-448. In control rats housed at 24 degrees C, hepatocytes showing high immunoreactivity to cytochrome MC-P-448 were located in the centrilobular areas of the hepatic lobules, whereas they disappeared markedly in the 4-week cold-exposed rats. In 1-week and 2-week cold-exposed rats, only a slight decrease in the expression of MC-P-448 positive hepatocytes was observed. These changes were clearly seen by visual inspection of the distribution topography as determined by a microphotomeasurement technique. In conclusion, cytochrome MC-P-448 forms which were predominantly located in centrilobular areas in the hepatic lobule decreased in 4-week cold-exposed rats. This was in contrast to our early report which showed an increasing tendency of cytochrome PB-P-450 forms in 4-week cold-exposed rats.
Kobayashi
Y
Y
Department of Clinical Pathology, Saitama Cancer Center, Japan.
Motohashi
Y
Y
Miyazaki
Y
Y
Kishi
K
K
Takano
T
T
D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D003081:Cold Climate; D019388:Cytochrome P-450 CYP1A2; D003580:Cytochromes / Q000378:metabolism*; D007150:Immunohistochemistry; D008099:Liver / Q000201:enzymology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D003580:Cytochromes; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2