acid-phosphatase and retinol-palmitate

The effect of prepubertal retinyl palmitate treatment on uterine development and uterine capacity was determined. Gilts remained intact or were unilaterally hysterectomized-ovariectomized (UHO) on d 28, 84, or 112 of age. Starting at birth, half of the gilts in each UHO group were treated with retinyl palmitate (14,000 IU.kg-1.wk-1) and half received control carrier solution. All intact gilts received control carrier solution. Blood samples (d 28, 56, 84, and 112 of age) were analyzed for retinoid and retinol-binding protein (RPB). At UHO, part of the excised uterine horn was processed for morphometric analysis of the uterine wall, and tissues were incubated in minimal essential medium with [3H]leucine to assess total protein and RBP production. After puberty, gilts were mated and then killed on d 44 to 47 of pregnancy; uterine length, number of corpora lutea and fetuses, and fetal, placental, and empty uterine weights were recorded. Endometrial tissues were incubated in minimal essential medium with [3H]leucine, and nondialyzable radioactivity, acid phosphatase, and RBP production were measured. During the prepubertal period, retinyl palmitate treatment decreased (P < .05) myometrial area (longitudinal and circular), but it had no effect on other components of the uterine wall or production of nondialyzable radioactivity or secretion of RBP by uterine tissue. During pregnancy, prepubertal retinyl palmitate treatment increased (P < .05) uterine length but had no effect on uterine weight, number of fetuses, placental or fetal weights, or endometrial production of nondialyzable radioactivity, acid phosphatase, or RBP. Therefore, prepubertal retinyl palmitate treatment at the dosage administered had no effect on uterine capacity.

Topics: Acid Phosphatase; Aging; Animals; Anticarcinogenic Agents; Diterpenes; Endometrium; Female; Hysterectomy; Leucine; Litter Size; Organ Size; Ovariectomy; Pregnancy; Random Allocation; Retinol-Binding Proteins; Retinyl Esters; Sexual Maturation; Swine; Tritium; Uterus; Vitamin A

Vitamin A is stored in the lipid droplets of liver stellate cells (LSCs), as retinyl esters whose hydrolysis is necessary for the secretion of retinol into the blood. Here, we isolated these retinyl esters under their physiological form, i.e., in LSC lipid droplets, which had retained their morphological and biochemical characteristics. These retinyl esters are substrate for an hydrolytic enzyme, whose optimum pH is 4.1, and which is kinetically similar to the acidic retinyl ester hydrolase (aREH) we had previously described (Mercier et al., Biochim. Biophys. Acta (1994) 1212, 176-182). The cellular and subcellular localizations of aREH activity in rat liver suggest that this enzyme could be involved in the hydrolysis of the esterified vitamin A stores.

Topics: Acid Phosphatase; Adipocytes; Animals; Carboxylic Ester Hydrolases; Cell Fractionation; Cells, Cultured; Diterpenes; Electrophoresis, Polyacrylamide Gel; Hydrogen-Ion Concentration; Lipid Bilayers; Lipids; Liposomes; Liver; Male; Microscopy, Electron; Rats; Rats, Wistar; Retinyl Esters; Vitamin A

The behaviour of subcultures of vitamin A-treated human embryo fibroblasts was studied from the point of view of morphology, growth characteristics, karyology and agglutinability at subsequent passages after treatment. Evidence was obtained that vitamin A-induced rupture of lysosomes may lead to transient alterations in the pattern of growth, structure of the membranes and morphology in cell generations deriving from the cells injured by the action of the vitamin.

Topics: Acid Phosphatase; Cell Aggregation; Cell Division; Cell Line; Chromosomes, Human; Concanavalin A; Diterpenes; Fibroblasts; Humans; Lysosomes; Palmitates; Retinyl Esters; Vitamin A; Vitamin D