Additive effects of protein malnutrition and cortisol on plasma proteins and immunoglobulins of pregnant rats, and their offsprings

This research work was carried out to study the effects of two immunosuppressive mechanisms: protein malnutrition and cortisol treatment on the feto-maternal unit. Therefore, plasma Ig G and Ig M levels were tested in pregnant rats submitted to a low protein diet (4%) and cortisol treatment (0.5 mg/100 g b.w.) during pregnancy and in their offspring. Nutritional status was evaluated by measuring ponderal parameters and plasma protein levels in rat dams and their neonates. Thus, a fall in ponderal parameters and in plasma protein levels was observed, both in rat dams suffering protein malnutrition as well as in their newborns. Cortisol treatment produced a decrease in the ponderal parameters of the control group, and an increase in plasma protein levels of the malnourished one, both in rat dams and in their neonates. Apparently, protein malnutrition might lead to a low functionality of B lymphocytes, caused by a decrease in Ig G and Ig M rates of malnourished rat dams. Ig M levels, however, increased in neonates as a consequence of possible concomitant infections. Cortisol treatment promoted humoral immune deficiency, since Ig G and Ig M levels decreased both in the control and in the malnourished pregnant rat groups. Nevertheless, cortisol administration seemed to increase susceptibility to infection in the newborns, especially in those born from malnourished rat dams.     

Effects of deteriorated frying oil and dietary protein levels on liver microsomal enzymes in rats

This study was conducted to investigate the effects of deteriorated used frying oil (DUFO) and dietary protein levels upon the hepatic microsomal drugmetabolizing enzyme system. Fresh soybean oil was subjected to a deep-frying process at 205±5°C for four six-hr periods. The resultant DUFO was incorporated into high protein (HU) (27% lactalbumin) or low protein (LU) (8% lactalbumin) test diets at a 15% level. High protein (HF) and low protein (LF) diets containing fresh soybean oil served as the control. Male Long-Evans young rats fed the test diets for eight weeks showed decreased fat absorption and increased red blood cell (RBC) in vitro hemolysis. The activities of hepatic aminopyrine N-demethylase (AD), aniline hydroxylase (AH), NADPH-cytochrome C reductase (NCD), UDP-glucuronyl transferase (UDPGT) and glutathione S-transferase (GST) as well as cytochrome P-450 content were significantly increased in rats fed the HU diet. However, the AD, AH and GST activities, as well as the cytochrome P-450 content of the LU group, were increased to a lesser extent and significantly lower than those of the HU group. Rats fed the LU diet were the only group that showed significantly elevated serum GOT (E.C. 2.6.1.1, glutamate-oxaloacetate transaminase) and GPT (E.C. 2.6.1.2, glutamatepyruvate transaminase) values. Supplementation of 0.3% DL-methionine to the HU diet further increased GST activity. Unexpectedly, rats fed the low protein control diet (LF) also had raised levels of AD, AH and UDPGT activities as well as in vitro RBC hemolysis. It was concluded that rat hepatic microsomal enzymes are induced by dietary DUFO and that the level of induction is influenced by dietary protein level.     

Effect of dietary restriction on the plasma apolipoprotein pattern in cholesterol-fed rabbits

Dietary restriction (half of the control ration) was performed in rabbits given either standard or cholesterol-rich diets. The plasma apolipoproteins were studied on the total, d<1.21, lipoprotein fraction using polyacrylamide gel electrophoresis. A marked rise in the amount of both apo-B and apo-E appeared in cholesterol-fed rabbits and was enhanced by dietary restriction. These results reflect the aggravation of hypercholesterolemia when cholesterol feeding is carried out in underfed rabbits. In all groups only one molecular species of apo-B, identified as apo-B-100, was present after overnight fasting. Thus, lipoproteins which accumulate in the plasma following cholesterol feeding, associated with dietary restriction or not, probably are remnants of hepatogenous triglyceride-rich lipoproteins.     

Influence of dietary fats on butyrylcholinesterase and esterase-1 (ES-1) activity in plasma of rats

We studied the effects of dietary fats, especially fish oil, on the activities of esterase-1 (ES-1) and butyrylcholine-sterase in the plasma of rats. The identification of nutritional determinants of these enzymes could provide clues as to their physiological function. Fish oil, when compared with corn oil, consistently caused increased activities of both enzymes. Plasma ES-1 activity, but not butyrylcholinesterase activity, was increased after isocaloric replacement of carbohydrates by coconut fat. Dietary medium-chain triglycerides, when compared with corn oil, produced decreased and increased activities of butyrylcholinesterase and ES-1, respectively. Various plant fats, such as corn oil, linseed oil, coconut fat, palm oil, palm kernel oil, soybean oil and rapeseed oil, did not differentially influence butyrylcholinesterase activities. Plasma triglyceride concentrations were lowered by fish oil and increased by coconut fat and palm kernel oil. For individual rats in 5 out of 6 experiments, weak, negative correlation coefficients of the order of 0.3 were found between the changes in plasma butyrylcholinesterase activities and in plasma triglyceride concentrations.     

Effect of varying levels of dietary protein on tumor development and lipid metabolism in rats exposed to aflatoxin

Reports in the literature concerning the relationship of protein nutrition to aflatoxicosis are contradictory. In an attempt to elucidate this relationship more clearly, we have examined the effects of low, normal, and high protein-containing diets on tumor incidence and development, as well as on several biochemical indices, in rats which have been exposed to low levels of aflatoxin in a “chronic” rather than “acute” situation. In our study, male weanling rats were place for 3 months on otherwise adequate diets containing either 8, 22, or 30% casein with and without aflatoxin B₁ at 1.7 ppm. Half of the animals in each group received diets which were further supplemented with the amino acid, cystine, at 0.6% of the diet. (Sulfur-containing amino acids are the most limiting amino acids in casein, and the addition of cystine to the diet serves to improve the biological quality of the protein source.) After 3 months the animals were fed control diets without aflatoxin until they were killed at 1 year. Weight gain was markedly decreased and liver weights increased in response to aflatoxin in all groups except those on the low protein diets, where aflatoxin had no effect on these protein diets, where aflatoxin had no effect on these indices. No tumors were found in the livers of rats fed the low protein, aflatoxin-supplemented diet. In the other groups, the severity of the liver involvement increased progressively with increased protein levels in the diet. When cystine was included in the diet, tumors were observed also in the animals fed the low protein diet; furthermore, the livers of those animals on “normal” and high protein diets were much more severely involved than were the livers of animals on non-cystine supplemented diets. Plasma cholesterol levels were increased in response to aflatoxin when the diets containing 22 and 30% protein were fed and when cystine was included in the 8% protein diet. Liver cholesterol levels were increased in response to aflatoxin in all groups except in those receiving the low protein diets. Among these latter animals, aflatoxin administration had no effect on liver cholesterol values. Changes as a result of aflatoxin administration were also observed in the fatty acid composition of sterol esters, triglycerides, and phospholipids of liver and tumor tissue.     

Influence of dietary saturated fatty acids on the regulation of plasma cholesterol concentration

The specific effects of individual fatty acids (FA) on plasma cholesterol levels, in the range habitually consumed by humans, is not usually presented by the literature. Conclusions have been made regarding the cholesterolemic effect of individual FA, even though these FA cannot be tested individually. It appears that FA balance of the diet may be more important than individual FA intakes. Variation in plasma cholesterol response to diet is influenced by many factors, such as gene-nutrient interactions. The effect on human health of current processes used in the food industry that are certain to change dietary fat composition and TG structure is yet to be fully explored. Some of the relevant research regarding dietary fat and plasma cholesterol levels is reviewed.     

Influence of dietary fat and protein on serum cholesterol of cholesterol-fed chicks

Summary Cottonseed oil, partially hydrogenated cottonseed oil and corn oil, were fed at 4% and 10% of the diets with two levels of protein, 19% and 25%, and with 0.5% cholesterol to cockerels 21 days of age for a period of 38 days. Blood samples were obtained at 0, 14, 24, and 38 daysvia heart puncture. The data indicate that the serum cholesterol value, irrespective of the level or type of fat, was significantly lower in those groups of birds which were fed the higher level of protein. Excluding the combination of 19% protein and 10% cottonseed oil, the degree of saturation did not have any apparent effect upon serum cholesterol because the mean differences among the oils and between the fat levels were not statistically significant.     

Effect of dietary lard containing higher alpha-linolenic acid on plasma triacylglycerol in rats

It is well known that the consumption of n-3 polyunsaturated fatty acid (PUFA) decreases the plasma triacylglycerol (TAG) level. The technology of elevating the content of n-3 PUFAs in pig meat has already reached a practical level. In this study, the effects of dietary lard containing higher alpha-linolenic acid (LNA) on plasma TAG were compared with those of normal lard in rats. The rats were fed a diet containing either 10% normal lard or a high linolenic lard for 4 weeks. The plasma and liver TAG levels in the high linolenic lard group were significantly lower than those in the normal lard group. The activity of the fatty acid synthase (FAS) of the liver in the high linolenic lard group was significantly lower than that in the normal lard group. The contents of n-3 PUFAs in hepatic total lipid, TAG fraction, and the phospholipids (PLs) fraction increased in the high linolenic lard group. The results indicate that the high linolenic lard suppressed hepatic FAS activity compared with the control lard, resulting in a lower concentration of plasma TAG. These results also suggest that pig meat containing high LNA may be more nourishing than normal pig meat.     

Influence of dietary fats on pancreatic phospholipids of chronically ethanol-treated rats

Male rats were given liquid diets by pair-feeding for 24–30 days, and phosphatidylinositols in pancreas were analyzed as derivatives of diacylglycerols and fatty acids. Addition of arachidonic acid or changing the fat component (35 energy%) in the liquid diet from olive oil/corn oil to oil fromBorago officinalis, which contains 22% γ-linolenic acid, increased the fraction of arachidonoyl-containing species. This fraction was decreased by more than 50% by substituting ethanol for 36 of the 47 energy% provided by carbohydrate. A smaller difference between ethanol-fed and control rats was seen in the composition of phosphatidylcholines and phosphatidylethanolamines. There was no difference in the composition of phosphatidylinositols when fat, instead of ethanol, was used to substitute the 36 energy% in the diet containing olive oil/corn oil. Substituting ethanol for 28 of 35 energy% provided by fat as corn oil in a liquid diet had no effect on the fraction of arachidonoyl-containing species. The results indicate that the effect of ethanol on phosphatidylinositols in pancreas is not due to a deficiency of arachidonic acid, and that the effect of the ethanol-containing diet is not due to the lowered carbohydrate content. However, high contents of fat or of ethanol appear to be necessary for the effect.     

Effects of cholesterol feeding to maternal rats on metabolism of cholesterol and bile acids in the dams and their offspring

The influence of feeding cholesterol to rats during pregnancy and postpartum (from the 11th day of gestation to the third day after delivery) on the serum and hepatic cholesterol levels and on the bile acid composition in the pool and in the liver in relationship to the dams and their pups was examined. The hepatic content of cholesterol in both dam and offspring increased during cholesterol feeding without any changes in serum cholesterol level. In the dams, mainly the esterified cholesterol was increased; in the pups, mainly the free cholesterol was increased. Cholesterol feeding led to a pronounced increase in the pool of β-muricholic acid and a relative decrease in the lithocholic acid concentration in pregnant rats. In fetal rats, the chenodeoxycholic acid pool was increased by cholesterol intake. The lithocholic acid pool was larger in the postpartum rats fed cholesterol than in the controls, while the concentration of α- and β-muricholic acids was decreased. The neonates of cholesterol-fed dams had a larger pool of chenodeoxycholic acid but a smaller pool of β-muricholic acid. These results suggest that the metabolism of cholesterol and of bile acids in dams and their offspring respond differently to cholesterol intake.     

Effects of ethanol ingestion and dietary fat levels on mitochondrial lipids in male and female rats

The effects of sex, dietary fat levels, and ethanol ingestion on rat liver mitochondrial lipids have been studied. Two groups of male animals were fed either a low-fat diet for about 76 days or a high-fat diet for about 52 days, and two groups of female animals were fed the same low-fat diet for about 50 days or the high-fat diet for about 37 days. Ethanol was substituted isocalorically for carbohydrate and amounted to 36% of total calories. The total as well as individual concentrations of fatty acids, phospholipids, and neutral lipids were determined in all eight groups of animals. Variable changes were observed in the total fatty acid composition of mitochondria from each of the four groups of animals. After ethanol ingestion, there was a decrease in arachidonate/linoleate ratio in males, while no change was observed in females. Increasing the fat content of the diet decreased this ratio in both controls and experimentals, but it did not alter the effects of ethanol on either sex. Presumably, this was due to the fact that corn oil was the only source of lipid. After ethanol ingestion, the total fatty acid concentration increased in all groups of animals except the males fed the low-fat diet. A decrease was observed in this group. The same pattern of change was reflected in changes in total phospholipid concentrations. In each case, the majority of the concentration change in total phospholipid could be accounted for by changes in phosphatidylcholine (PC). Measurement of choline oxidase (C.O.) showed that ethanol ingestion increased C.O. activity only in the low-fat group of males. No change was observed in the other three groups. Chronic ethanol ingestion is known to increase the methylation of phosphatidylethanolamine (PE); therefore, in order to decrease PC, the increase in C.O. in the low-fat males must have been of sufficient magnitude to offset the increase in PE methylation. Increasing the fat content of the diet offset the effect of ethanol on C.O. in males. Neither ethanol nor fat exerted much effect on C.O. in females. These results emphasize the importance of dietary levels of fat as well as sex in the study of liver mitochondria structure and function in relation to ethanol metabolism. This work was presented at the AOCS Meeting, New York, May 1977, at which J.A.T. was an Honored Student Awardee.     

Effects of dietary fats on prostanoid production and aortic and plasma fatty acid composition in rats

Male Sprague-Dawley rats were fed diets with 10%, 30%, or 50% of energy derived from fat for two weeks. The fats used were beef tallow, olive oil, peanut oil and butter. Aortic prostacyclin (PGI₂) production, platelet aggregation and thromboxane A₂ (TXA₂) production and plasma and aortic phospholipid (PL) content were measured. Butter- and beef tallow-feeding reduced aortic PGI₂ production and collagen-induced TXA₂ production in a dosedependent manner as the level of fat in the diet increased. Neither olive oil nor peanut oil had any effect on aortic PGI₂ production or collagen-induced TXA₂ production. Butter-feeding also resulted in a decrease in collageninduced platelet aggregation; however, none of the other fats had any effect on collagen-induced platelet aggregation. The observed decreases in aortic PGI₂ and collagen-induced TXA₂ production were paralleled by similar decreases in aortic and plasma PL arachidonic acid content and an increase in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Only the most saturated fats, butter and beef tallow, had significant inhibitory effects on prostanoid production and platelet aggregation.     

Maternal protein deficiency in rat: Effects on central nervous system gangliosides and their catabolizing enzymes in the offspring

Maternal protein deficiency imposed on rats a month prior to conception, and during gestation and lactation, resulted in a significant cell loss in cerebrum, cerebellum, brain stem and spinal cord of pups at weaning. The cerebellum was the most affected central nervous system (CNS) region; it contained only 25% of the normal cell number. Undernourished pups were also found to have a lower concentration of total gangliosides in cerebrum as compared to that of controls. However, the total ganglioside concentration was unaffected in the cerebellum, brain stem and spinal cord by maternal undernutrition. In all regions, undernutrition caused significant changes in the proportions of individual gangliosides; these alterations were region-specific. Sialidase, β-galactosidase, β-glucosidase, and β-hexosaminidase, which are involved in the catabolism of gangliosides, showed higher activities in all the regions of undernourished pups, suggesting that these enzymes may play a role in maintaining the porportions of various ganglioside fractions.     

Influence of protein malnutrition on the phagocytic function of neutrophils in rats

A study was carried out to determine the effect of protein deficiency on the phagocytic function of blood neutrophils and of peritoneal exudate of rats. The deficient animals exhibited significantly lower leukocyte and neutrophil values, as well as NBT reduction and diminished peroxidase and bactericidal capacity. Englobement of S. aureus and latex particles was found to be normal in both groups. Alkaline phosphatase activity in the neutrophils appear to be increased in the deficient animals.     

腹水中单克隆抗体IgG和IgM的含量测定

作者采用电泳扫描法测定腹水中McAb IgG和IgM的含量。该法的优点是不需要任何特殊试剂,操作简便,并适用于测定不同特异性的McAb。     

Effects of nutritional copper deficiency on adult non-pregnant and pregnant rats and their newborns.

The effects of nutritional copper deficiency on weight gain, food intake and fertility of pregnant and non-pregnant adult Wistar rats, and weight of newborns, were studied. The adult animals were subjected to diets with different copper content (control-5 ppm; moderate deficiency -1.2 ppm; severe deficiency -0.3 ppm) for six weeks (non-pregnant) and nine weeks (pregnant). No effect on weight gain or appetite was seen in the groups of animals subjected to copper deficiency. Fertility, as evaluated by the number of conceptuses and liverborns of the pregnant animals, and weight of newborns also, were not impaired. These data show that not only the extent of deficiency, but also the period during which it is imposed, as well as its duration, condition the appearance of alterations of this deficiency.     

The effect of dietary erucic acid on cardiac triglycerides and free fatty acid levels in rats

Male Sprague-Dawley rats, 3 weeks of age, were fed semisynthetic diets containing test oils at 20% by weight for 3 days, 1 week, and 16 weeks. The test oils contained up to 22.3% erucic acid. Growth retardation was evident in rats fed rapeseed oil high in erucic acid, and soybean oil and Tower rapeseed oil diets containing about 5% erucic acid. Cardiac triglyceride accumulation was found in rats fed diets containing about 5% erucic acid but not in rats fed Tower rapeseed oil which contains 0.2% of this acid. The cardiac free fatty acid levels were low, 50–100 μg/g of wet heart tissue, and were not affected by feeding diets containing about 5% erucic acid. Feeding a diet containing a high erucic acid rapeseed oil did result in higher free fatty acid levels but only at 3 days and 1 week; the level at 16 weeks was similar to the other oils. The fatty acid analysis of cardiac triglycerides and free fatty acids showed high percentages of erucic acid at 3 days and 1 week; at 16 weeks these levels had declined significantly. The results indicate that the accumulated erucic and eicosenoic acids, at 3 days and 1 week, accounted for the increase in cardiac free fatty acids when rats were fed the high erucic acid rapeseed oil. There appears to be no evidence that the early cardiac triglyceride or free fatty acid accumulation is related to the formation of the long term myocardial lesions. Contribution No. 739 Animal Research Institute.     

Effect of dietary calcium during pregnancy and lactation on zinc levels in blood and bone, in rats

The effect of dietary calcium (Ca) level on maternal zinc (Zn) nutritional status was studied. Female Wistar rats, weighing 250-350 g, were fed during pregnancy and lactation with an experimental diet containing/100 g different levels of calcium: 0.2 g (low calcium: LCa), 0.6 g (normal calcium: NCa) or 0.9 (high calcium: HCa). Maternal blood samples were drawn from the tail at delivery and at the end of lactation. Laboratory determinations were: Zn in whole blood (WB) at delivery and weaning; Zn (ZnF) and Ca (CaF) in the ashed femur at weaning. The results (mean +/- SEM) were: ZnWB (microgram/ml) at delivery and weaning: LCa: 8.73 +/- 1.05; 12.8 +/- 2.02; NCa: 3.49 +/- 0.19; 3.73 +/- 0.37; HCa: 3.21 +/- 0.19; 3.85 +/- 0.27. CaF (mg/100 mg): LCa: 19.2 +/- 0.8; NCa: 21.4 +/- 0.6; HCa: 20.4 +/- 1.1. ZnF (microgram/100 mg): LCa: 30.2 +/- 0.9; NCa: 24.1 +/- 0.3; HCa: 24.1 +/- 0.9. ZnWB was significantly higher in LCa (p < 0.0001) regarding NCa and Hca. ZnF showed an increase and CaF a decrease in LCa regarding NCa and HCa (p < 0.0001). There were no significant differences in ZnWB, ZnF and CaF between NCa and HCa These results show that: there was no detrimental effect when dietary Ca content was increased by 50% above the normal requirements of the rat.; low dietary Ca during pregnancy and lactation produced an increase of Zn utilization, reflected in maternal blood Zn and in ZnF content.     

Influence of sources of dietary oils on the life span of stroke-prone spontaneously hypertensive rats

In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n=23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4±4.0 d) was not significantly different (P>0.05) from those fed low-sulfur canola oil (89.7±8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6–13 d, P<0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times, indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.