background: retinoids have been suggested to play a role in oogenesis and oocyte survival. objective: in the present study the effects of retinol palmitate were investigated on differential follicular counts in response to superovulation as well as follicle quality after vitrification of ovaries. materials and methods: ten, 4 week old female balb/c mice were randomly assigned to either paraffin...

Retinol acetate hydrolase is localized in rat liver microsomes whereas the retinol palmitate-hydrolyzing activity was found in the nuclear and in the mitochondrial lysosome-rich fractions. Acetone-dried powder from whole rat liver retained all of its retinol palmitate-hydrolyzing activity. Ammonium sulfate fractionation of the acetone-dried powder yielded a partially purified enzyme liberating ...

Retinol acetate hydrolase is localized in rat liver microsomes whereas the retinol palmitate-hydrolyzing activity was found in the nuclear and in the mitochondrial lysosome-rich fractions. Acetone-dried powder from whole rat liver retained all of its retinol palmitate-hydrolyzing activity. Ammonium sulfate fractionation of the acetone-dried powder yielded a partially purified enzyme liberating ...

The amounts of endogenous retinyl palmitate, retinol and retinaldehyde were measured in the neural retina and retinal pigment epithelium (RPE) of predominantly cone (chicken), rod (rat) and more mixed (cat, human) retinae. The ratio of 11-cis to all-trans isomers of retinyl palmitate and retinol in the neural retina and the RPE increases progressively with the increase in diurnality of the spec...

Absorption and fluorescence studies of retinol (vitamin A alcohol) and retinol palmitate (vitamin A palmitate) intercalated in phosphatidylcholine (PC) liposomes show that these compounds are bound to the lipid bilayer. It is further found that retinol binds liposomes with greater affinity as compared to retinol palmitate. In addition, the delivery of liposome-incorporated retinoids to the bloo...

Retinoids have been reported to produce regressions in metaplastic changes of the mucosal epithelium. In order to define the role of these micronutrients in the prevention of squamous metaplasia of the oral cavity, it is necessary to measure their uptake in target tissues such as the buccal mucosal epithelium. We demonstrated in a trial that retinyl palmitate applied topically via a toothpaste ...

Adipose tissue is an important storage depot for retinol, but there are no data regarding retinol mobilization from adipose stores. To address this, dibutyryl cAMP was provided to murine BFC-1beta adipocytes and its effects on retinol efflux assessed. High performance liquid chromatography analysis of retinol and retinyl esters in adipocytes and media indicated that cAMP stimulated, in a time- ...

Newly absorbed chylomicron remnant retinyl ester is endocytosed by parenchymal liver cells, and retinol is subsequently transferred to perisinusoidal stellate cells in liver. In the present study we have used several approaches to elucidate the mechanism for the paracrine transfer of retinol between liver parenchymal and stellate cells. In one series of experiments, chylomicrons labeled with [3...

Much of our knowledge about the relationship between micronutrients and cancer comes from studies in which plasma (serum) micronutrient levels have been correlated with cancer incidence; however, the relationship between the concentrations of micronutrients in the plasma and in the target tissues has not been established. Ninety-three subjects (62 males and 31 females ages 42-86, median age 69)...

I . The mean liver retinol reserve (retinal+ retinyl esters, expressed as retinol) of six newborn lambs was 21 ? 8 pg. The mean value for ten suckled lambs, aged 5-7 days, was 2655 +47z pg retinol per liver. 2. Three unsuckled lambs were fed ad lib. from birth for 28 days on a high-protein diet, based on lard and skim milk, without supplementary vitamin A. The diet provided sufficient vitamin A...