Annales de la nutrition et de l'alimentation最新文献

Ethanolic extract containing soluble sugars was prepared from avocados (variety americana) coming from Madagascar. In this extract, thin layer and paper chromatography showed the presence of a ketoheptose, the mannoheptulose, in amount of 0.1 g/ml extract or 1.1 g/100 g fresh pulp. Physiological experiments were performed with avocado extract and comparatively with a sample of commercial mannoheptulose. Six-month-old rats were given by stomach tube 10 mM CaCl2 solution (+ 45Ca) containing a carbohydrate. Depending on the group, the carbohydrate was 20 and 100 mM glucose (control), D-mannoheptulose 200, 100, 50 and 25 mM, avocado extract concentrated or diluted 1/2, 1/4, 1/8, 1/16. Blood samples were taken at different times after the administration and plasma radioactivity was measured. Rats were sacrificed at 24 hours; femur and axis radioactivity was used as a measure of calcium absorption. Both mannoheptulose and avocado extract were potent on calcium absorption. This absorption increased progressively with sugar concentration, in mannoheptulose and avocado groups. The interpretation of these results was discussed and also their application to the Nutrition in tropical and subtropical countries.

This paper deals with the effects of various parameters involved in plant nitrogen metabolism, on the nitrate content in carrot roots. Level of mineral nitrogen supply, activity of leaves and light intensity have been taken into account in factorial experiments. Results are discussed with a view to the improvement of the quality of root production with respect to their nitrate content.

Implantation of MtT-F4 tumor, a mammotropic tumor that secretes large quantities of ACTH, GH and prolactin, into male Fisher rats induced the development of hyperlipidemia. Free fatty acid, triglyceride and cholesterol levels in the plasma were significantly increased at 31 days after tumor implantation. Blood glucose and glycerol levels remained normal, while uric acid concentration in the blood was significantly decreased. The concentrations of the serum lipoproteins were significantly increased, while, only small changes in the distribution of the serum lipids and the composition of the lipoproteins were observed. Following stimulation of isolated adipose tissue cells with ACTH, the lipolytic response and the accumulation of cyclic AMP was higher in cells derived from the rats with the tumor, although the accumulation of cyclic GMP was not different from control adipocytes. Further, when the isolated adipose tissue cells were stimulated with dibutyryl cyclic AMP no difference was observed between the control and tumor bearing groups. Clofibrate administered in the diet resulted in a complete elimination of the tumor effect on serum triglycerides and to a great extent prevented the rise in serum cholesterol. The tumor-induced increase in the concentration of the high density lipoproteins was not affected, but the elevation of the d less than 1.063 lipoproteins was not affected, but the elevation of the d less than 1.063 lipoproteins was partially reversed. The increased lipolytic response and accumulation of cyclic AMP following stimulation by ACTH was not altered in adipocytes derived from tumor bearing rats. However, clofibrate treatment resulted in a significantly greater accumulation of cyclic GMP in fat cells stimulated with ACTH from both control and tumor bearing rats. Clofibrate in the diet did not alter the levels of GH or prolactin or serum lipids in the control rats nor were the elevated hormone levels of the tumor bearing rats changed.

The increase rate of DNA synthesis and mitotic activity in popliteal lymph nodes following subplantar injection of PHA was significantly reduced in rats subjected to a protein-free diet given for 9 weeks. On the contrary, the lymph node responses to Con A were higher with latter diet than with a balanced 18% casein diet. On the other hand, PHA reduced the weight and proliferative activity of the thymus, and probably also increased the emigration of thymocytes in protein deprived rats, while Con A was devoid of any effects. Thus, mainly the activity of the PHA-responsive subset of T lymphocytes and thymocytes appeared to be disturbed after protein deprivation. According to previous work, this subset was formed of high theta, cortisone-sensitive celles.

The Moore's hypothesis concerning a relationship between the metabolism of copper and that of vitamin A led us to consider a possible relationship between this vitamin and ceruloplasmin, the carrier protein for copper. Experiments were carried out on Sprague-Dawley rats. The ceruloplasmin level of control animals and vitamin A - deficient rats was determined An average increase between 22 and 33% was observed in the animals with vitamin A deficiency, the highest levels being observed in the females. These results are in agreement with Peterson's previous work. A second type of experiment was carried out to confirm these results. The rats were raised in a copper-deficient diet and the vitamin A level was regularly determined. In these conditions serum and liver levels of vitamin A are normal and do not vary, ceruloplasmin level is zero; however apoceruloplasmin is still being synthetized : Nevertheless at the ultime state of the deficiency vitamin A level decreases while apoceruloplasmin increases. These results raise the following question. Could the relationship between ceruloplasmin and vitamin A be possibly due to an inflammatory state in vitamin A deficient rats. In this respect a third series of experiments were undertaken and are in progress; the vitamin A and ceruloplasmin levels are regularly determined.

The mean-term physiological effects of brassidic acid (n-9, trans docosenoic acid) and of erucic acid (n-9, cis docosenoic acid) have been compared to those of their C 18 homologues, elaidic and oleic acid, in a 2(3) factorial experiment; the 3 tested factors are: 1) the chain length of the dietary monoenes (C 22:1 vs. C 18:1), 2) the geometrical configuration of their double bond (trans vs. cis) and 3) the dietary level of linoleic acid (30% vs. 1,7% of dietary fatty acids). Wistar weanling rats have been fed for 16 weeks semi-synthetic diets containing 15% of lipids by weight, in which the fatty acids under study (brassidic, erucic elaidic) ranged to 40%. Although caution has been taken to optimize the digestibility of brassidic acid (interesterification of the lipid mixture, reduced level of calcium in the diet, addition of monoglycerides), it remains lower that of erucic acid. However, because of different levels of food consumption, the absorbed amounts of the two isomers are about the same. With a high dietary supply of linoleic acid, the dietary monoenes (C 22:1 or C 18:1), cis or trans) do not induce great changes in the weight gain of the rats, when adjusted to food consumption; linoleic acid subdeficiency lowers this adjusted weight gain, except when the diet contains oleic acid as the only monoene. These effects do not parallel those observed on the absolute growth of the rats. The trans monoenes, and to a lesser extent, erucic acid, induce an increase of liver weight (adjusted to body weight). The light microscopic histological study of the heart does not reveal any difference between the brassidic acid fed-rats and those fed the C 18:1 monoenes (elaidic, oleic). In contrast, erucic acid induces definite lesions of the myocardium. The dietary level of linoleic acid has little influence on the incidence and the severity of the lesions. The effects of these dietary fatty acids on the lipid contents and fatty acid compositions of different organs will be reported in a second paper.

In order to evaluate the effect of measles on proteins carrying vitamin A, we have examined 58 children with measles (24 have been seen again 2 weeks later) and 52 healthy controls of similar age and nutritional status. During the course of fever we have observed a high urinary excretion of urea and creatinine with proteinuria while the hydroxyproline index is significantly lower than in the controls. Irrespective of the nutritional status the plasma levels of albumin, prealbumin and R.B.P. are consistantly low. Two weeks later, while the albumin level has decreased, the other parameters are aiming towards normal values. The higher levels of prealbumin and R.B.P. suggest a reactivation of the hepatic protein synthesis. The urinary excretion of R.B.P. has not changed significantly during measles. We have observed rather high urinary losses of R.B.P. in the controls. The low levels of plasma prealbumin possibly do not allow the complete binding of the R.B.P.

Substituting soya oil for lard considerably reduced hypercholesterolemia in the male rat with induced hypercholesterolemia due to a dietary overlead of cholesterol and sodium deoxycholate. The decrement was more marked when a mixture of 80 p. 100 soya oil + 20 p. 100 sardine oil replaced the lard. This improvement of the hypocholesterolemic effect by adding sardine oil to soya oil was due to the long-chain fatty acids (mainly C20:5 and/or C22:5 n-3 in the fish oil).

Weanling male rats were fed ad libitum for 6 weeks with a normal or vitamin-A-deficient diet and then meal-fed 1 1/2 hours per 24 hours a 65 p. 100 glucose diet for not less than 3 weeks. The stomach of meal-fed rats develop and food intake is sufficient to ensure a normal rate of growth until deficients reached a plateau of weight. After the single daily meal the respiratory quotients are remaining high (QR greater than 1) all throught the day and decreases during the night (0,8) with all the animals. Fasting glycemia, insulinemia and liver glycogen of meal-feds are higher than ad libitum rats ones, but lower in deficients than in controls. Activities of NADPH2-linked enzymes (G6PDH, 6PGDH and NADP malate DH) are increased in meal-feeding, but avitaminosis A reduces by half this increase.