Effect of a vitamin A-free diet on [3H]diazepam and [3H]GABA binding in the rat retina.

Benzodiazepine and GABA binding sites in the rat retina are influenced by a vitamin A-free diet. In rats fed a vitamin A-free diet, the total number of [3H]GABA and [3H]diazepam binding sites was markedly higher than in rats given a balanced diet. No differences were found in the apparent affinities of [3H]GABA and [3H]diazepam for their specific binding sites. The results suggest that GABA and benzodiazepine binding sites have a role in the function of the retina.

[Vitamin "A" and biological membranes. Nota V - Fatty acid composition of erythrocyte stroma in vitamin A deficient rats (author's transl)]. / Vitamina "A"' e membrane biologiche. Nota V - Composizione in acidi grassi degli stromi degli eritrociti di ratti albini in avitaminosi A

Two groups of albino male rats, were fed for 90 days with a balanced and vitamin A-free diet rispectively, to observed changes, if any, in the fatty acid composition of erythrocyte membranes. The blood was separated with heparin, total lipids from erythocyte stroma were extracted and fatty acids analyzed by gaschromatography. It was noticed an increase in saturated fatty acids; at the same time mono- and, above all, polyunsaturated fatty acids decreased; the results agree with those obtained in rats fed for 30 and 60 days with Vitamin A-free diet as similar changes were observed in liver mitochondrial membranes of the rats, under study, we presume vitamin A modifies, to some extent, the biosyntesis of unsaturated fatty acids.

[Vitamin "A" and biological membranes. Nota VI-Fatty acid composition of liver mitochondrial membranes in vitamin A-deficient rats (author's transl)]. / Vitamina "A" e membrane biologiche. Nota VI-Composizione in acidi grassi delle membrane dei mitocondri epatici di ratti albini in avitaminosi A

The results we obtained in studying the fatty acid composition of erythrocyte stroma on vitamin A-deficient rats, led us to repeat the experiment on liver mitochondrial membranes. Two groups of albino male rats, of the Wistar strain, were fed for 90 days with a balanced and a vitamin A-free diet respectively. The animals were killed, total lipid from the membranes of liver mitochondria were extracted and fatty acids separated by gas-chromatography. It was noticed an increase in the percentage of saturated fatty acids; at the same time, mono and polyunsaturated fatty acids decreased. The results agree with those obtained in rats fed for 30 and 60 days with vitamin A-free diet. This seems to support the interpretation that vitamin A modifies, to some extent, the metabolism of polyunsaturated fatty acids.

[Intestinal glucose absorption in rats of different ages (author's transl)]. / Assorbimento intestinale del glucosio in ratti di differente etá

We studied the intestinal glucose absorption in a colony of rats at different ages. The experiment was carried out on animals of the following ages: 3, 5, 10 and 20 months. All rats were fasted 48 hr prior to the administration of 2 ml. 50% glucose solution by an oesophageal sound. After one hour the animals were killed, the intestine was washed with a determinated quantity of distilled water and homogenized, to find out any trace of glucose in mucose cells. Glucose absorption was calculated as the difference between the quantity introduced and that left in the intestine. The results of this experiment show that glucose absorption expressed as mg/100 gm. body weight/hr decrease significantly during the first 10 months, with no marked changes there after. Absorption rapidly increase during the first 16 month, if expressed as mg/hr. This is probably due to a remarkable weight increase without a proportional increase of intestinal length.

[Distribution and depletion with time of retinol-C14 in different tissues and organs of albino rats]. / Distribuzione e deplezione nel tempo di retinolol-C14 in differenti tessuti ed organi di ratti albini.

Albino male rats of Wistar strain, weighing about 350 g., were administered orally a single dose of 2,50 mu C of retinol-C14 after a fast of 24 h. At intervals of 3 h and of 3, 6, 12, 18 and 24 days rats were killed; livers, kidneys, blood, white fat tissue and brown fat tissue were removed. Samples were dried and radioactivity was measured. From the results, expressed in mu C/g of dry tissue, it is clear that vitamin A is taken up by all tissues. After 3 days it decreases in all tissues, between the 3rd and 18th day, its rate is constant and the depletion is complete within 24 days.

[Influence of a high protein diet on the urinary and fecal excretion of calcium in albino rats]. / Influenza della dieta iperproteica sull'escrezione urinaria e fecale del calcio in ratti albini.

Albino rats (Sprague-Dawley) of mean weight 100 g were divided into four groups and given for 7 days a balanced diet. They were then placed in metabolic cages for fifteen days and fed diets containing different quantities of casein: 18% (D18), 36% (D36), 50% (D50) and 72% (D72). The levels of total calcium, inorganic phosphorus, alkaline phosphatase activity, total proteins and urea were determined. The urinary and fecal excretion of calcium were determined on specimens of urine and stool collected every two days. The metabolic balance of nitrogen was also estimated. The results show there is not a linear relationship between a high protein diet and plasma protein levels, but a progressive body calcium loss was observed with the increase of casein in the diet, which confirms what other workers have already suggested.

[Variations of retinol-C14 incorporation in rats of different ages fed a vitamin A-free diet]. / Variazioni dell'incorporazione del retinolo-C14 in ratti di differente età alimentati con una dieta priva di vitamina A.

Two groups of Wistar strain male albino rats of different age were treated with a large dose (300 I.U.) of vitamin A-acetate, after 24 h fasting. Each rat was then administered orally a single dose of 1,25mu C retinol-C14 to determine the rate of incorporation into different tissues. At intervals of 3 h and of 3, 6, 12 days the rats were killed; liver, kidney, blood, white fat tissue, brown fat tissue were taken and dried. Radioactivity was measured. The results show that in all tissue the mean percentage of incorporation, expressed in muC/g dry tissue, is generally higher in young than in adult rats.

[Nutritional surveys in some centers of 3 provinces of Sardinia. II. Nutrition and tradition]. / Rilevamenti alimentari in alcuni centri di tre province della Sardegna: Nota II Alimentazione e tradizione.

The differences between the nutritional habits we noticed in the villages under study, concern the geographical position, the kind of agricultural or pastoral economy and industrialization. However, these are not the only decisive factors. In some villages where average income in high, tradition still influences nutritional habits, as the preference for some typical dishes suggests. In other villages, where income is low, but where progress has been rapidly reached, the preference for more sophisticated or advertised foods seems to prevail.

[Dietary habits of apparently healthy boys and hospitalized adults]. / Le abitudini alimentari di ragazzi apparentemente sani e di adulti ospedalizzati.

We required into the nutritional habits of adolescents--presumably in good health--and of hospitalized adults. We observed that caloric excesses, through equally distributed in protides, carbohydrates and lipids, might be negative factors in young people who practise no sports; taking into account that their diet was similar to the diet of that patients suffering from metabolic and cardiovascular diseases, used to eat when they were young.

[Uptake of retinol-C14 into different tissues of vitamin A deficient albino rats]. / Incorporazione di retinolo-C14 in differenti tessuti di ratti albini a dieta priva di vitamina A.

Groups of rats were fed a vitamin A free diet for 30, 60 and 90 days. They were then administered orally a single dose of 1,25 microC of retinol-C14. After 3 h, 3, 6 and 12 days from the administration, the incorporation into the different tissues was determined. The results show that the incorporation decreases, on the average, as the experimental period and the intervals after the administration of retinol-C14 grow longer.

[Uptake of retinol-C14 into liver mitochondrial membranes and erythrocyte stroma of albino rats on a vitamin A-free diet]. / Incorporazione di retinolo-C14 nelle membrane dei mitocondri epatici e nello stroma dei globuli rossi di ratti albini a dieta priva di vitamina A.

We have determined the incorporation of retinol-C14 into liver mitochondrial membranes and blood cell stroma in albino male Wistar strain rats, fed with a vitamin A deficient diet for 30, 60 and 90 days. At the end of the vitamin A deficient period, rats were kept fasting for 24 hours and then administered orally retinol-C14 (1,25 microC). They were divided into groups and killed after 3 hours, 3, 6, 12 days from the administration of retinol-C14. The incorporation is very high in one-month deficient rats, it decreases as the experimental period and the intervals after the administration of retinol-C14 grow longer.

[Effects of vitamin A (retinol), Tioadenolo and a standard diet on the plasma lipid pattern in the rat on an atherogenic diet]. / Effetti della vitamina A (retinolo), del Tioadenolo e di una dieta standard sul quadro lipemico del ratto a dieta aterogena.

The Authors have examined the action of large doses of vitamin A (2000 U.I./Kg diet) compared with that obtained by administration of a lipid lowering drug (Tioadenolo) and a standard diet in albino rats feed at first an atherogenic diet for 15 days. The "recovering" diets were adminisetred for 15 and 30 days. Serum components were obtained with routine chemical-clinical assay, membrane lipids and related fatty acids by the method of Folch in erythrocytes isolated by the method of Wipple. Both retinol and Tioadenolo lower blood plasma and cell membrane lipids more than a standard diet.