PubMed Health⌕ Search

Biomedical subjects

R Pion

Publications and source records attributed to R Pion.

At least 19 recordsLinked to original sources
PubMed1991

[Comparative digestive and metabolic utilization of beans, lentils and chick peas in the rat].

Faba bean, lentil or chick-pea raw seeds were used as the only protein food in the rat. The balanced diet was designed to suit growth requirements. Nitrogen apparent digestibility coefficient (CUDa) was 72% in the faba bean, 75% in the lentil, 76% in the chick-pea groups respectively, but the CUDa of some essential amino acids were much lower: 52-51-71% for methionine, 60-39-78% for cystine, 73-71-75% for valine, while arginine CUDa values (87-87-82) were higher than all other AA CUDa values. Growth rate (8.9-6.7-9.1 g/d) and food intake index (2.1-2.5-2.2) were satisfactory. Blood and muscle free amino acid concentrations related to digestible intake showed that methionine from the 3 legumes, threonine from chick-pea, arginine and lysine from faba bean were not fully available.

Amino Acids↗
PubMed1985

[Protein metabolism in the newborn lamb. I. Impact of the ingestion of colostrum on blood glucose, blood levels of gammaglobulin and free amino acids in tissues].

Ten newborn lambs were divided into two groups at birth. Five of them were fed hourly with cow colostrum; the others (unfed lambs) were given saline. Jugular blood levels of glucose, urea, free amino acids and IgG1 were measured during the 10-hour period following birth. The lambs were then exsanguinated under pentobarbital anaesthesia. Free amino acid levels were determined in liver, muscle (longissimus dorsi) and skin. The glycogen contents of the liver and whole body were measured. The IgG1 levels were determined in the intestinal wall and in the contents of the abomasum and small intestine. The blood glucose levels increased after birth in both groups and did not differ significantly in either group. After colostrum feeding, hepatic glycogen and blood urea concentrations were higher in fed than in unfed lambs. Blood free essential amino acid levels which increased after birth in the fed group, were higher in that group than in the unfed one. Nonessential free amino acid levels remained nearly constant throughout the experimental period and did not differ significantly in either group (fig. 2). Free threonine and valine in the liver, skin and muscle were higher in the colostrum-fed lambs than in the others. IgG1 levels increased after birth in the blood of the fed lambs and seemed to be closely related to the intestinal contents of these compounds (fig. 3). The amount of blood free essential amino acids provided by the hydrolysis of colostral proteins was estimated at about 43% of the amount entering the small intestine.

Aging↗
PubMed1983

Glucagon binding to purified liver plasma membranes from growing rats undergoing energy restriction.

The purpose of this work was to investigate liver glucagon receptors in growing rats fed a control diet (11.8% crude protein) or a high-protein diet (19.8% crude protein) given in restricted amounts. The animals were fed every 4 hours. 125I-glucagon binding to purified liver plasma membranes was studied. Membrane purity was analysed with marker enzymes. The alteration of glucagon during incubation was measured. The results show that specific 125I-glucagon binding increased with time at 30 degrees C, reaching a maximal value within 120 min. The increasing level of unlabelled glucagon inhibited 125I-glucagon binding at steady state. Apparent specific 125I-glucagon binding at steady state was lower in experimental animals than in controls. This correlated with the increase in glucagon breakdown and decrease in membrane purity. Alternatively, glucagon binding to its receptors could drop. Unlabelled glucagon excess produced a time-dependent dissociation of glucagon-receptor complexes (half-life: up to 1 h). Feeding the experimental diet increased the dissociation of labelled glucagon-receptor complexes.

Animals↗
PubMed1980

[Effect of hyperinsulinemia on liver insulin receptors of the growing rat subjected to energy restriction].

Two experiments (I and II) were carried out to study the interaction of insulin with amino acid metabolism in rats subjected to a restricted energy allowance (Grizard et al., 1975). 61 male rats, weighing 94 g at the beginning of the experiments, were divided into 4 groups and fed every 4 hrs. Group T was fed a balanced diet, and groups -E1, -E2 and -E3 were given a restricted energy allowance (table 1). The rats of group -E3 were injected with insulin at 11 a. m. every day, and those of group -E2 at that hour on the day they were killed. When the animals of a group had a mean body weight of 157 g, they were killed between 2 p. m. and 6 p. m., i. e. between two meals. Plasma insulin and insulin binding to liver plasma membranes were recorded. Reducing dietary energy intake resulted in a small decrease of postprandial plasma insulin and in a small increase of the plasma insulin clearance rate (table 2). It also augmented (125I) iodoinsulin binding to liver plasma membranes (fig. 1). This change could explain the increment of the liver protein synthesis observed in such animals (Arnal, Fauconneau and Pech, 1972). Exogenous insulin induced a resistance to insulin effects (Grizard, Prugnaud and Pion, 1977), and caused a large increase of plasma insulin and a small decline in (125I) iodoinsulin binding to liver plasma membranes for 3 to 5 h after the injection (fig. 1). A large increment in insulin binding was then noted (fig. 1). Increased insulin binding and decreased plasma insulin might be correlated. The enhanced insulin binding could not explain the resistance to the effects of insulin.

Animals↗
PubMed1980

[Effect of diet and microflora on amino sugars in the digestive contents and faeces of rats, lambs and preruminant calves].

Glucosamine (Glc NH2) and galactosamine (Gal NH2) were determined by an automatized chromatographic method in samples from digestive contents and faeces. Germfree lambs and rats as well as conventional preruminant calves, lambs and rats were used in the experiments. The rats were fed an irradiated casein diet, the lambs UHT milk and the preruminant calves various diets (table 1). Concentrations of Glc NH2 and of Gal NH2 reached 6 g/16 g of N in the caecal contents and the faeces of germfree rats (table 2). Concentrations of Gal NH2 were 7 to 12 times lower and those of Glc NH2 4 times lower in conventional rats. In lambs, the amino sugar concentrations (table 3) found in the stomach contents resembled those supplied by the milk. In contrast, in the large intestine and the faeces, the concentration of amino sugars was very high. In conventional lambs, those concentrations were 8 to 4 times lower. For ruminant calves, the concentrations of amino sugars (table 4) were greater in the ileal contents than in the faeces. They reached that of meconium when the calves were fed milk. The lowest values were observed in the faeces of calves fed soya, colostrum or fish diets which are less digestible than milk. In germfree animals, the hexosamines were endogenous. In conventional animals, bacterial metabolism led to an increase in faecal Glc NH2/Gal NH2. In the calves fed soya or fish diets, the hexosamine content in the faeces was low owing to the dilution of bacterial and endogenous mucoproteins by the undigested dietary proteins.

Animals↗
PubMed1978

[Effect of dietary protein levels on the amount of blood free amino acids in lambs].

Growing lambs were fed increasing amounts of nitrogenous matter (12 to 20 per 100 on dry matter basis). Free amino acid and urea levels were measured in blood of 37 kg lambs. When crude protein content of diets exceeded 16 per 100, the catabolism of several essential amino acids increased. Methionine, lysine and histidine seemed to be limiting for growing lambs.

Amino Acids↗
PubMed1978

[Effects of technological processing on digestive and metabolic utilization of amino acids from various protein foods].

The use of vegetable proteins such as legumes or oilseeds proteins is often restricted by antinutritional or toxic factors. Therefore, it is usefull, in order to extend their consumption, to isolate proteins from most of the other components of the seeds. Unfortunately, the technological processes may have some deleterious effects on the nutritive value of the proteins. Moreover, the proteins isolates and concentrates need further processing to be texturated in order to look like conventional foods for humans. We used growing rats to study the effect of some of these technological processes on the nutritive value of some field bean and sunflower protein feedstuffs. We estimated the digestive utilization of dry matter, nitrogen and amino acids, and the amino acid composition of feces was used in trying to explain some decreases in nitrogen digestibility. We also studied the ability of their amino acids to be used for growth, and tried to estimate their availability from blood and muscle free amino acids determinations. It may be inferred from the results that the technologists were successfull in improving their processes, and that textured field beans and sunflower proteins of good nutritional quality may be processed now.

Amino Acids↗
PubMed1977

[Effect of energy restriction during late pregnancy on plasma insulin, blood glucose, blood urea and blood free amino acids in pregnant and suckling sheep].

The experiment was carried out in autumn using 27 Limousine ewes during pregnancy and lactation. Some blood essential and non-essential free amino acids increase during late pregnany. Blood glucose, blood urea and blood free threonine, valine and glycine increase after parturition. Reducing the energy supply of the ration during late pregnancy results in a decrease of plasma insulin and blood free tyrosine, phenylalanine and alanine.

Amino Acids↗
PubMed1976

[Comparison of the digestive utilization of methionine, of its hydroxylated analog, and of sodium sulfate in goats using 35s compounds].

35S and 35S free and protein bound amino acids were estimated in goats' abomasal contents and blood after ruminal injections of sulfer labelled compounds: methionine, methionine hydroxy analog (M.H.A.) and sodium sulfate. 35S incorporation into microbial and plasma proteins was higher with methionine than with M.H.A. or sulfate. 35S.M.H.A. utilisation seems to be less different from Na2 35SO4 utilisation than from 35S methionine utilisation.

Abomasum↗
PubMed1976

[Influence of L-leucine overloading on the level of free amino acids in the diabetic rat].

Alloxan injection in the rat results in a large increase of branched free amino acids (leucine, isoleucine, valine) in the blood, liver and muscle; it decreases most of the non essential free amino acids in liver. L-leucine administration in the diabetic rat results in a large decrease of plasma corticosterone. It increases free leucine but decreases free isoleucine and valine in blood and muscle. It decreases most of the essential free amino acids in liver.

Amino Acids↗
PubMed1976

[Influence of feeding rhythm on blood insulin in growing rats].

Plasma insulin in ad libitum fed growing rats increases during dark hours and decreases during light hours. In contrast, meal fed growing rats [6 equal meals at regular interval during the day] exhibit a constant plasma insulin level. It may be inferred that improvement of nitrogen retention in meal fed rats is not related to an increase in insulin secretion.

Animals↗
PubMed1975

Rubella vaccination: fertility control in a large-scale vaccination program for postpubertal women.

Despite nationwide immunization programs, rubella infections during pregnancy continue. To solve this serious health problem direct immunization of women of reproductive age may be required. On a clinic basis, using nonphysician personnel, we vaccinated 404 susceptible women, ages 18 to 33; half were sexually active. Since pregnancy is proscribed for 2 to 3 months following rubella vaccination, a full range of family-planning services and a variety of contraceptive methods were used to ensure sustained fertility control. Sixteen vaccinees presented with possible conceptions in a 3 month follow-up. Of these, only five required treatment: two received diethylstilbestrol, two had menstrual inductions, and one an abortion. Administration of vaccine during a menstrual period was effective in preventing inadvertent vaccination of pregnant women. It was concluded that contraceptive counseling with adequate pregnancy termination backup makes it feasible to give rubella vaccine to highly motivated women.

Contraception↗
PubMed1975

[Effect of heating in the presence or absence of glucose on digestive and metabolic utilization of amino acids of casein].

The effect of heating casein with and without glucose was studied with growing rats. Apparent digestibility of dry matter, organic matter, crude protein and amino acids was recorded. The utilization of amino acids was studied by estimating food consumption, growth and blood and muscle free amino acids. Heating casein with glucose at 90 degrees C during 24 hours resulted in significant loss of lysine and affected food intake, protein efficiency ratio and protein digestibility. Threonine and lysine availabilities were lowered.

Amino Acids↗
PubMed1975

[Protein and energy value of spiruline blue algae supplemented by amino acids: digestive and metabolic utilization by the growing rat].

Protein and energy value of 6 samples of "Spirulina" was studied on growing rats in 1972 and 1973. Sample RL 1(Spirulina platensis, originating from Tchad) was grown in artifical conditions in a laboratory. Others samples (Spirulina maxima) were grown in the solar evaporator near Mexico, washed and dried either on heated rollers (MR8, MR13) or by spraying (MA 7, MA10). Sample MA10 D corresponds to sample MA10, bleached by ethanol plus acetone (Baron, 1975). Each Spirulina sample was the only protein source of balanced, starch diets. The diets were supplemented in essential amino acids (E.A.A.) according to the requirements of growing rats (table 1). The ratios [(digestible nitrogen/metabolisable energy (EM] of the Spirulina diets were similar to that of the control diets containing herring meal. The diets were fed to groups of 15 to 17 growing rats. Energy and nitrogen balances were established by the comparative slaughter technique. Blood and muscle samples were taken at slaughter for the determination of free amino acids levels.

Amino Acids↗