Cytosolic ferritin and lipid-associated ferritin are metabolically different in guinea-pig livers

Abstract

A distinct pool of liver ferritin has been described in man, guinea pigs and rats [Cham, Roeser, Nikles & Ridgway (1986) Clin. Chim. Acta 158, 71-79]. This ferritin accounts for approx. 30% of total intracellular ferritin. It differs from previously described cytosolic and 'microsomal-fraction' ferritin by its firm association with lipid and by the absence of heat-stability at 75 degrees C. The present study demonstrates that cytosolic ferritin and lipid-associated ferritin in guinea-pig livers have distinctly different rates of turnover. Cytosolic ferritin has a rate of turnover approx. 3.5 times as high as lipid-associated ferritin. The apparent metabolic heterogeneity suggests that the two forms of ferritin may have different functional roles.

Determination of vitamins A, D, E, and K in human and bovine serum, and β-carotene and vitamin A palmitate in cosmetic and pharmaceutical products, by isocratic HPLC

“…Vitamins A, D3, and E in yogurt have been quantified by use of amperometric detection with a glassy carbon electrode at a potential of + 1300 mV [7]. Retinoids, carotenoids, and vitamin K1 have been monitored after separation by use of a mobile phase gradient and, after coulometric reduction, with a fluorescence detector [13,15]. Thermospray mass spectrometry in series with a UV absorbance detector has been used for the analysis of vitamin D and its metabolites [22].…”

Ascorbic acid deficiency affects the metabolism of cytosolic ferritin but not lipid-associated ferritin in livers of guinea pigs

“…The diet and experimental conditions of the animals were as published previously (Cham et al. 1989).…”

“…Ferritin has been defined as a soluble protein that serves as a source of iron storage in the body (Worwood, 1986). It has since been shown that a significant proportion of ferritin is present as non-soluble protein in the liver of various mammals (Cham et al, , 1988(Cham et al, , 1989). This ferritin can be solubilized by lipid solvent systems (Cham et al, 1986) or by non-ionic detergents (Cham et al, 1988).…”

“…This ferritin can be solubilized by lipid solvent systems (Cham et al, 1986) or by non-ionic detergents (Cham et al, 1988). The newly described ferritin pool has therefore been termed lipid-associated ferritin (LAF) (Cham et al, , 1988(Cham et al, , 1989. The difference between cytosolic ferritin (CYF) and LAF is not only physicochemical (Cham et al, 1986(Cham et al, , 1988 but also metabolic (Cham et al, 1989).…”

“…The newly described ferritin pool has therefore been termed lipid-associated ferritin (LAF) (Cham et al, , 1988(Cham et al, , 1989. The difference between cytosolic ferritin (CYF) and LAF is not only physicochemical (Cham et al, 1986(Cham et al, , 1988 but also metabolic (Cham et al, 1989). At homoeostasis the rate of turnover of CYF is much higher than that of LAF. Ascorbic acid is involved in a large number of cellular metabolic events.…”