0000000000006802
AUTHOR
Jacques Belleville
Effects of age, and protein malnutrition followed by a balanced diet on the non-parallel change in digestive enzymes in the pancreas and their secretion in the rat.
1. Ninety male Wistar rats were divided into two groups. A control group (C) was fed on a balanced diet, containing 200 g protein/kg for 51 d. An experimental group (E) was fed on a low-protein diet containing 50 g protein/kg for 28 d (PM), and then on a balanced diet for 23 d (BR). At different days of PM and BR, the pancreas and the pancreatic juice were collected 40 min after injection of 0.1 mCi [3H]leucine. The amounts of amylase (EC3.2.1.1), trypsinogen 2 (EC3.4.21.4), chymotrypsinogen 1 (EC3.4.21.1) and lipase (EC3.1.1.3) were determined after separation by the isoelectric focussing technique. Incorporation of [3H]leucine into the four hydrolases of pancreatic juice and pancreas was …
Fructose-enriched diet modifies antioxidant status and lipid metabolism in spontaneously hypertensive rats
Abstract Objective High-fructose consumption in industrial countries has been shown to induce metabolic abnormalities or syndrome X. Changes in antioxidant defense are unknown in hypertension associated with metabolic disorders induced by high-fructose feeding. Methods Twenty spontaneously hypertensive rats were assigned to one of two groups; one received a fructose-enriched diet (60% fructose) and the other a starch diet. After a 13-wk diet period, total antioxidant status was assessed in the blood and liver by monitoring the rate of free radical-induced red blood cell hemolysis. Antioxidants (enzymes and vitamins) were determined in blood and liver. Gene expression of antioxidant enzymes …
Age-related changes in cholesterol metabolism in macrosomic offspring of rats with streptozotocin-induced diabetes.
The aim of this study was to determine the impact of diabetic macrosomia on cholesterol and lipoprotein metabolism. Age-related changes in the activities of serum LCAT, hepatic HMG-CoA reductase, cholesterol 7α-hydroxylase, and ACAT, the major enzymes involved in cholesterol metabolism, were determined in macrosomic offspring of streptozotocin-induced diabetic rats. Hepatic, serum, and lipoprotein cholesterol contents were also examined. Mild hyperglycemia in pregnant rats was induced by intraperitoneal injection of streptozotocin (40 mg/kg body weight) on day 5 of gestation. Control pregnant rats were injected with citrate buffer. At birth, macrosomic pups had higher serum, LDL-HDL1, and H…
Dietary fish protein lowers blood pressure and alters tissue polyunsaturated fatty acid composition in spontaneously hypertensive rats.
Abstract Objectives To investigate the effect of two types of dietary protein on blood pressure, liver fatty acid desaturation and composition, and urine 6-keto-prostaglandin-F (PGF1α) level, the metabolite of prostacyclin. Methods 5-wk-old spontaneously hypertensive rats were fed 20% casein or purified fish protein. The fat source was 5% ISIO oil, which contains 47.9% (ω-6) and 1.7% (ω-3) total polyunsaturated fatty acids. After 2 mo on the diet, systolic blood pressure was reduced with fish protein compared with casein (189.8 ± 10.5 versus 220.7 ± 8.7). Results Excretion of 6-keto-PGF1α in urine was negatively correlated with blood pressure. Liver cholesterol and phospholipid concentratio…
Time course of changes in serum glucose, insulin, lipids and tissue lipase activities in macrosomic offspring of rats with streptozotocin-induced diabetes.
The aim of this investigation was to determine the time course of changes in serum glucose, insulin and lipid levels, as well as lipid and protein content and lipolytic activities in insulin target organs (liver, adipose tissue and muscle), in macrosomic offspring of streptozotocin-induced mildly hyperglycaemic rats. Food intake and nutritional efficiency were also evaluated. Mild hyperglycaemia in pregnant rats was induced by intraperitoneal injection of streptozotocin (40 mg/kg body weight) on day 5 of gestation. Control pregnant rats were injected with citrate buffer. At birth, macrosomic pups (birth weight > 1.7 S.D. greater than the mean value for the control pups) had higher serum …
Age and Protein Restriction Followed by Balanced Refeeding Affect Pancreatic Digestive Enzyme Outputs and Turnover Times in Rats
Outputs and turnover times of trypsinogen 2, chymotrypsinogen 1, lipase and amylase were determined in pancreatic juice of growing male Wistar rats at various times during protein restriction (5% protein) followed by balanced refeeding (20% protein). In control rats fed a 20% protein diet, trypsinogen 2, chymotrypsinogen 1 and amylase outputs increased progressively with age, those of lipase remained constant and the turnover times of the four hydrolases were shortened. With time, protein restriction induced the most rapid decrease in trypsinogen 2 output, followed by that of amylase, then by those of trypsinogen 1 and lipase. Compared with controls, protein restriction enhanced specific ra…
Changes in plasma lecithin: cholesterol acyltransferase activity, HDL2, HDL3 amounts and compositions in patients with chronic renal failure after different times of hemodialysis
The aim of this study was to investigate the effect of hemodialysis duration on HDL(2) and HDL(3) compositions and lecithin:cholesterol acyltransferase (LCAT) activity in 58 patients on acetate hemodialysis using cuprophane membrane, after different periods of dialysis. Patients were divided into three groups-GI1 year, GII 1-5 years, GIII 5-13 years of dialysis and were compared with 22 controls. Increase by 34% of triacylglycerols (TG) was noted in GI and by 36% in GII versus GI. Hypertriglyceridemia was correlated with hemodialysis duration (HD) (r=0.75, P0.05). The LCAT activity decrease by 25% was noted in GII versus GI (P0.05) and by 45% in GIII versus GI (P0.01), this activity was neg…
Changes in lipid metabolism and antioxidant defense status in spontaneously hypertensive rats and Wistar rats fed a diet enriched with fructose and saturated fatty acids
Abstract Objective Larger doses of fructose and saturated fat have been associated with oxidative stress and development of hypertension. The effects of modest amounts of fructose and saturated fatty acids on oxidative stress are unknown. Methods To increase knowledge on this question, 10-wk-old spontaneously hypertensive rats and Wistar rats were fed for 8 wk with a control diet or an experimental diet enriched with fructose (18%) and saturated fatty acids (11%; FS diet). The total antioxidant status of organs and red blood cells was assayed by monitoring the rate of free radical-induced red blood cell hemolysis. Sensitivity of very low-density lipoprotein and low-density lipoprotein (VLDL…
Digestion and absorption rates of [3H]-oleic acid and [14C]-triolein do not differ in rats fed heated (-) and (+) gossypol cottonseed and soybean flours.
This study was conducted to compare in vivo the acute effects of heated (+) and (-) gossypol cottonseed flours with those of soybean flour on lipid digestion and absorption in growing rats. Rats were fed by gastric intubation mixed [ 3 H]-oleic acid and [ 14 C]-triolein with heated flours or without flour (control). Lipid digestion and absorption were determined for 6 h after meal intubation. Both radioactivities recovered in gastrointestinal tract were significantly higher in rats fed (+) gossypol cottonseed flour than in all other groups. The majority of both recovered radioactivities was found in stomach contents, then in stomach wall and finally in intestinal wall. The distribution of b…
Long term hemodialysis aggravates lipolytic activity reduction and very low density, low density lipoproteins composition in chronic renal failure patients.
Abstract Background Dyslipidemia, particularly hypertriglyceridemia is common in uremia, and represents an independent risk factor for atherosclerosis. Methods To investigate the effects of hemodialysis (HD) duration on very low density lipoprotein (VLDL) and low density lipoprotein (LDL) compositions and lipopolytic activities, 20 patients on 5 to 7 years hemodialysis were followed-up during 9 years. Blood samples were drawn at T0 (beginning of the study), T1 (3 years after initiating study), T2 (6 years after initiating study) and T3 (9 years after initiating study). T0 was taken as reference. Results Triacylglycerols (TG) values were correlated with HD duration (r = 0.70, P Conclusion De…
Hepatic storage and transport of n-3 and n-6 polyunsaturated fatty acids by very-low-density lipoproteins in growing rats fed low- or adequate-protein diets with sunflower, soybean, coconut, and salmon oils
Protein and essential fatty acid (EFA) deficiencies may both occur in chronic malnutrition and have common symptoms. To determine the interactions between dietary protein intake and EFA availability, rats were fed purified diets containing 20% or 2% casein and 5% as one of four fats (sunflower, soybean, coconut, or salmon oil) that differed particularly in their n-6 and n-3 polyunsaturated fatty acids (PUFAs). Protein malnutrition enhanced hepatic triacylglycerol and cholesterol concentrations while decreasing hepatic protein and phospholipid contents and mass and components of very-low-density lipoprotein (VLDL). The ratio of PUFAs to saturated fatty acids (SFAs) was consistently depressed…
A Polyunsaturated Fatty Acid Diet Lowers Blood Pressure and Improves Antioxidant Status in Spontaneously Hypertensive Rats
gamma-Linolenic acid [GLA, 18:3(n-6)], eicosapentaenoic acid [EPA, 20:5(n-3)] and docosahexaenoic acid [DHA, 22:6(n-3)] have been reported to prevent cardiovascular diseases. However, they are highly unsaturated and therefore more sensitive to oxidation damage. We investigated the effects of a diet rich in these polyunsaturated fatty acids (PUFA) on blood pressure, plasma and lipoprotein lipid concentrations, total antioxidant status, lipid peroxidation and platelet function in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). Five-week-old SHR and WKY rats were fed for 10 wk either a diet containing Isio 4 oil or a diet rich in GLA, EPA and DHA (5.65, 6.39 and…
Low-protein diet prevents tissue lipoprotein lipase activity increase in growing rats
The time course of changes in tissue lipolytic activities was studied in young rats during theconsumption of a low-protein diet containing 50 g protein/kg (40 g wheat gluten +10 g casein/kg) for 28 d followed by balanced refeeding with 200 g protein/kg (160 g wheat gluten +40 gcasein/kg) for 28 d. Lipoprotein lipase (LPL) activities were compared with the values of acontrol group fed a balanced diet containing 200 g protein/kg for 56 d. At the end of proteinmalnutrition period, the epididymal fat tissue LPL activity represented 36 %, and that of heartand gastrocnemius was 44 %, of those of the control group. These differences wereaccompanied by lower serum- and VLDL-triacylglycerols (TAG), …
Low birth weight at term impairs cord serum lipoprotein compositions and concentrations
The purpose of this study was to determine the effect of low birth weight at term on serum lipoproteins. Lipid and apolipoprotein (apo) contents were investigated in cord sera of small-for-gestational-age (SGA) newborns at term (2290 g +/- 33 g) and compared with those of appropriate-for-gestational-age (AGA) newborns (3570 g +/- 93 g). In SGA newborns, VLDL amounts were twofold higher, whereas LDL, HDL2 and HDL3 contents were lower than in AGA newborns (-38%, -44% and -42%, respectively). VLDL-triacylglycerols (TG), apo B-100 and apo E were higher, while VLDL-apo C-II values were 39% lower in SGA newborns compared with those of AGA newborns. In SGA newborns, HDL2-apolipoprotein, phospholip…
Changes in Serum and Lipoprotein Fatty Acids of Growing Rats Fed Protein-Deficient Diets with Low or Adequate Linolenic Acid Concentrations
The effects of a protein-deficient diet associated with sunflower oil [adequate in 18:2(n-6), poor in 18:3(n-3)] or soybean oil [adequate in both 18:2(n-6) and 18:3(n-3)] on lipid serum and lipoprotein compositions were studied in growing rats. Four groups of rats were fed different diets: SFC (20% casein + 5% sunflower oil); SFd (2% casein + 5% sunflower oil); SC (20% casein + 5% soybean oil); Sd (2% casein + 5% soybean oil). After 28 d, both protein-deficient groups exhibited low concentrations of protein, phospholipid, triacylglycerol and total cholesterol in serum and VLDL. Compared with rats fed 20% casein diets, those fed low protein diets had lower 18:2(n-6) and 20:4(n-6) in phosphol…
Unsaturated fatty acid bioavailability in growing rats fed low or adequate protein diets with sunflower or soybean oils
Abstract The relationship of serum very low density lipoproteins (VLDL) to hepatic lipid composition was studied after 28 days of protein depletion to determine the interactions between dietary protein levels and the essential fatty acid (EFA) availability. This was examined in rats using a dietary combination of 20% or 2% casein with 5% vegetable oils, variable in their n-6:n-3 fatty acid ratios. Rats were divided into four groups, SFC (20% casein + 5% sunflower oil ); SFd (2% casein + 5% sunflower oil ); SC (20% casein + 5% soybean oil ); Sd (2% casein + 5% soybean oil ). Dietary protein depletion decreased phospholipid and protein concentrations in liver and VLDL, whereas triacylglycerol…
Complémentarité et équilibre de l’apport alimentaire en protéines et en lipides
The nature and level of dietary protein is liable to influence cholesterol and essential fatty acid (EFA) metabolism. Dietary vegetable protein, particularly the undigested fraction, decreases intestinal cholesterol absorption, increases the faecal excretion of steroids, and enhances the catabolism of cholesterol-carrying lipoproteins by increasing the activity or number of LDL receptors. However, the hypocholesterolemic effect of protein may be due to the presence of non-protein components and hence the purity degree of the selected protein, and the concomitant addition or not of cholesterol. Dietary proteins with different amino acid composition may modulate the secretion of hormones (e.g…
Consommation alimentaire et durée d’hémodialyse chez l’insuffisant rénal chronique : corrélation aux paramètres nutritionnels
Resume Le but de cette etude est de decrire la consommation alimentaire de patients atteints d’IRC apres differentes durees d’hemodialyse et d’etablir des correlations avec les parametres nutritionnels. 58 patients repartis en 3 groupes : GI :
Changes in serum lipid and lipoprotein concentrations and compositions at birth and after 1 month of life in macrosomic infants of insulin-dependent diabetic mothers.
The aim of this study was to determine whether macrosomia related to maternal diabetes alters lipoprotein metabolism and whether these abnormalities still persist or regress after 1 month of life. Serum lipoprotein compositions and concentrations as well as serum lipid fatty acid compositions were investigated in macrosomic infants (birth weight = 4840 +/- 105 g at term) of insulin-dependent diabetic mothers at birth and after 1 month of life, and were compared to those of control infants (birth weight = 3400 +/- 198 g at term) of healthy mothers. Compared to controls, at birth, macrosomic newborns had higher serum lipids, apolipoprotein A-I and B-100, and lipoprotein (very low density lipo…
Réhabilitation nutritionnelle du rat à la suite d'une malnutrition protéique sévère. Effets comparés de la réhabilitation par la farine de coton et de soja sur les protéines et le cholestérol plasmatiques
Resume Le but de ce travail est de montrer experimentalement, par l'etude de divers constituants proteiques sanguins, que la farine de coton peut remplacer la farine de soja dans des regimes de rehabilitation nutritionnelle. Des rats de 70 ± 5 g au debut de l'experience subissent une carence proteique severe (2 % de caseine) durant 28 jours (MP), puis sont realimentes pendant 49 jours (RP) avec 4 regimes differents : rT (20 % de caseine), MSL (mais-sojalait, 60 %/30 %/5 %), MCL (mais-coton-lait, 60 %/30 %/5 %) et RCL (riz-coton-lait, 60 %/30 %/5 %). Des rats recevant durant toute l'experience le regime a 20 % de caseine servent de reference. La MP diminue les teneurs en albumine, mais propo…
Effect of refeeding diets containing cottonseed flour with traces of gossypol on rat liver and testis
The aim of the present work was to show that cottonseed flour introduced into rehabilitation diets is not nutritionally harmful. The cottonseed flour obtained from glandless seeds contains traces of gossypol. As gossypol is known to have pathological hepatic and testicular actions, the effects on hepatic variables and on the histological appearance of liver and testis of diets containing cottonseed flour were compared with those without cottonseed flour. Seventy growing male Wistar rats were divided into two groups. The control group (C) received a balanced diet (200 g casein+3 g methionine/kg) for 78 d and the experimental group was fed on a low-protein diet (20 g casein+3 g methionine/kg)…
Rat Plasma VLDL Composition and Concentration and Hepatic Lipase and Lipoprotein Lipase Activities Are Impaired during Two Types of Protein Malnutrition and Unaffected by Balanced Refeeding1
The relationships between VLDL concentrations and composition and changes in hepatic lipase and lipoprotein lipase activities were determined in rats, during the consumption of two low protein diets (2% casein or 5% gluten) (protein malnutrition) for 28 d, followed by the refeeding of a balanced diet for 14 d (15% casein) (refeeding). A control group was fed 15% casein for 42 d. In the control group, total lipolytic activity increased with age (r = 0.83, P < 0.001), whereas in both depleted groups, this activity remained low and stable throughout the period of protein malnutrition. At d 28 of protein malnutrition, plasma total lipolytic activities were significantly reduced in both depleted…
Dietary protein deficiency affects n-3 and n-6 polyunsaturated fatty acids hepatic storage and very low density lipoprotein transport in rats on different diets.
Fatty livers and the similarity between the skin lesions in kwashiorkor and those described in experimental essential fatty acid (EFA) deficiency have led to the hypothesis that protein and EFA deficiencies may both occur in chronic malnutrition. The relationship between serum very low density lipoprotein (VLDL) and hepatic lipid composition was studied after 28 d of protein depletion to determine the interactions between dietary protein levels and EFA availability. Rats were fed purified diets containing 20 or 2% casein and 5% fat as either soybean oil rich in EFA, or salmon oil rich in eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, or hydrogenated coconut, oil poor in EFA. Animal…
Pancreatic digestive hydrolase activities in growing rats fed alternately on raw and heated soya-bean flour.
The time-course effects of two diets containing raw (RSF) or heated (HSF) soya-bean flour on the digestive enzyme levels in the pancreas and in pancreatic juice were investigated in growing rats fed, alternately, on RSF or HSF diets for two 4-week periods. These values were compared with those obtained in a control group fed on a casein diet. RSF and HSF diets lowered N balance (84.8 (SE 0.9), 82.6 (SE 0.8) and 79.9 (SE 0.8) % with control, HSF and RSF diets respectively, at the third week). However, they increased protease activities compared with the control diet (3-fold for trypsin (EC3.4.21.4) and chymotrypsin (EC3.4.21.1) activities in pancreas contents and outputs with the RSF diet; 2…
Tissue antioxidant status differs in spontaneously hypertensive rats fed fish protein or casein
The present study was designed to determine whether changes in dietary protein source are related to changes in antioxidant status determined by enzyme activities of catalase, superoxide dismutase (SOD), gluthatione peroxidase (GSH-Px) and gluthatione reductase (GSSG-Red) and lipid peroxidation levels in various tissues. Spontaneously hypertensive rats (SHR; 5 wk old) were fed diets containing 20% casein or fish protein for 2 mo. Feeding the fish protein diet lowered blood pressure and reduced plasma total cholesterol levels and SOD activity in all tissues except muscle compared with the casein diet. Feeding fish protein also enhanced GSH level and GSH-Px activity in liver and heart, accomp…
Changes in fatty acid compositions of total serum and lipoprotein particles, in growing rats given protein-deficient diets with either hydrogenated coconut or salmon oils as fat sources
The present study examines the effects of dietary saturated (hydrogenated coconut oil) and polyunsaturated (salmon oil) fats on the composition and metabolism of lipoproteins in growing rats fed on protein-deficient diets. Four groups of rats were fed on the following diets for 28 d: 200 g casein+50 g coconut oil (COC)/kg, 20 g casein+50 g coconut oil (COd)/kg, 200 g casein + 50 g salmon oil (SAC)/kg, 20 g casein+50 g salmon oil (SAd)/kg. Both protein-deficient groups exhibited low concentrations of protein and triacylglycerol (in serum, very-low-density lipoprotein (VLDL), low-density lipoprotein-high-density lipoprotein, (LDL-HDL1) and HDL2-3), of cholesterol (in LDL-HDL1) and of phosphol…
Comparative changes between pancreas and pancreatic juice digestive enzyme contents during nutritional rehabilitation following severe protein malnutrition in the rat
The relationship between digestive enzyme activities in the pancreas and pancreatic juice was studied in post-weaning rats fed on a low-protein diet (30 g cereal protein/kg) for 1 month and a refeeding balanced diet (235 g mixed protein/kg) for the following 3 months. A control group was fed on the balanced diet for 4 months. At the end of malnutrition and at various times of refeeding, activities of amylase (EC3.2.1.1), trypsin(EC3.4.21.4), chymotrypsin (EC3.4.21.1), lipase (EC3.1.1.3), phospholipase A2 (EC3.1.1.4) and cholesterolesterase (EC3.1.1.13) in pancreas and pancreatic juice were measured. Recovery of body and pancreas weights was obtained after 3 months of refeeding. Pancreas off…
Relationship between rat liver microsomal Δ6 and Δ5 desaturase activities and fatty acid composition: comparative effects of coconut and salmon oils during protein restriction
International audience; The aim of this work was to compare the effects of coconut and salmon oils on rat liver microsomal Δ6 and Δ5 desaturations, during protein restriction. A higher Δ6 desaturase activity was noted in rats fed the low-protein coconut oil diet, in comparison with that occurring in rats fed either a low-protein or normal-protein salmon oil diet. No variation was observed in Δ5 desaturase activity or in 20:4n-6/ 18:2n-6 ratio. The fatty acid composition of liver microsomal phospholipids provided evidence of higher levels of 20:5n-3 and 22:6n-3 in the normal-protein salmon oil group, when compared with the low-protein salmon oil group. No influence of experimental diets on t…