Role of hepatic vitamin A and lipocyte distribution in experimental hepatic fibrosis.
Lipocytes are the major site of hepatic vitamin A storage, and they have been demonstrated to lose their vitamin A content in the process of hepatic fibrosis. To investigate the relationship between hepatic vitamin A content and the degree of hepatic fibrosis, we measured levels of retinyl palmitate and retinol in the CCl4-induced fibrotic liver using high-performance liquid chromatography. We estimated hepatic collagen content using a spectrophotometric analysis with sirius red, and also by measuring hydroxyproline levels. Lipocytes were detected by an immunoperoxidase method with anti-desmin antibody, and were counted morphometrically through a Texture Analyzing System. A significant negative correlation was observed between the level of retinyl palmitate and collagen content (r = -0.64) as well as the hydroxyproline level (r = -0.69) in the CCl4-induced fibrotic liver. In the process of fibrosis, hepatic retinol levels were elevated in association with a decrease in retinyl palmitate. In particular in the early stage of fibrosis, lipocytes increased remarkably in number in fibrotic areas in spite of a decrease in total hepatic vitamin A. The present study suggests that an increase in hepatic retinol as well as a decrease in retinyl palmitate may facilitate the process of hepatic fibrosis produced by lipocytes.
Yamane
M
M
Second Department of Internal Medicine, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
Tanaka
Y
Y
Marumo
F
F
Sato
C
C
D000818:Animals; D002251:Carbon Tetrachloride; D003094:Collagen / Q000378:metabolism; D004224:Diterpenes; D006909:Hydroxyproline / Q000378:metabolism; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives / Q000378:metabolism*
D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D003094:Collagen; D002251:Carbon Tetrachloride; D006909:Hydroxyproline