Effect of dietary trans fatty acids on cholinesterase and monoamine oxidase activities in different organs of rats

The effect of trans fatty acids and essential fatty acid deficiency upon the activities of cholinesterase and monoamine oxidase in livers, hearts, brains and lungs of rats was studied. This study was performed using three groups of male albino rats. Two out of these three groups were fed essential fatty acid low diets containing 10% hydrogenated coconut oil (HCNO) or margarine stock (MS, partially hydrogenated soybean oil) while the third group was fed an adequate supply of essential fatty acids through a diet containing 10% corn oil (CO). In the group of rats fed HCNO the activities of cholinesterase and monoamine oxidase in their livers, hearts, brains and lungs were not significantly different from those of the control group fed CO. In the group of rats fed MS, the activity of cholinesterase was significantly decreased in the livers, hearts and brains, but not affected in the lungs, while the activity of monoamine oxidase was significantly decreased in the livers and hearts but not affected in the brains and lungs as compared to the control group fed CO. The levels of serum total lipids, total cholesterol and triglycerides were elevated in both groups of rats fed HCNO or MS than in the group fed CO, but this elevation was more highly significant in the group fed MS than in the group fed HCNO.     

Metastatic lung teratoma--a case report

Oral administration of l g of 3-hydroxy-3-methylglutaric acid (HMG) before the ingestion of whiskey and a fatty meal markedly reduced the elevation of serum triglycerides, beta-lipoproteins, phospholipids, and cholesterol in man. In rats receiving an ethanol and corn oil mixture, HMG also inhibited the increase in postprandial serum and liver lipids. A comparative study of HMG and nicotinic acid in rats showed that, therapeutically, 50 mg MHG/kg body weitht is equivalent to 200 mg nicotinic acid/kg body weight in offering almost total protection against lipemic effects of ethanol.     

Variations in dietary fat and cholesterol intakes modify antioxidant status of SHR and WKY rats

The effects of varying dietary fat saturation [butter (B), beef tallow (BT)] or polyunsaturation [(n-6) soybean oil (SBO), (n-3) menhaden oil (MO)] and cholesterol content (0.05 and 0.5 g/100 g) on systolic blood pressure (SBP), plasma lipids and tissue antioxidant status were investigated in 14-wk-old spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats. Varying dietary fat composition for 9 wk had no influence on SBP in either SHR or WKY rats. Rats fed MO diets exhibited smaller (P < 0.05) body weight gains, lower (P < 0.05) feed efficiency ratios and lower (P < 0.05) plasma cholesterol concentrations than those fed the B, BT and SBO diets. Significant (P < 0.05) interactions for animal strain x cholesterol intake and animal strain x fat source were noted for serum cholesterol concentrations. SHR exhibited higher (P < 0.05) RBC and liver catalase (CAT), and heart and liver superoxide dismutase (SOD) activities similar to those of WKY rats. The lower (P <0.01) RBC, heart and liver glutathione peroxidase (GSH-Px) activities observed in SHR coincided with higher (P <0.01) glutathione reductase (GSSG-Red), compared with WKY rats. Dietary cholesterol intake had no effect on RBC, heart and liver total sulfhydryl concentration or GSH-Px activities, but increased (P <0. 001) liver GSSG-Red. Feeding MO resulted in lower (P <0.001) RBC and heart GSH-Px activities. In contrast, feeding B and BT resulted in lower GSH-Px in liver. The significant (P < 0.01) animal strain x fat source interaction obtained for liver GSH-Px activity indicated that SHR responded differently to polyunsaturated fatty acid feeding than their WKY counterparts. Diet-induced changes in tissue antioxidant status were tissue specific and did not affect the development of hypertension in SHR.     

Isolation of the Pichia pastoris PYC1 gene encoding pyruvate carboxylase and identification of a suppressor of the pyc phenotype

It has been reported that both n-3 and n-6 octadecatrienoic acids can increase hepatic fatty acid oxidation activity. It remains unclear, however, whether different enzymes in fatty acid oxidation show a similar response to n-3 and n-6 octadecatrienoic acids. The activity of hepatic fatty acid oxidation enzymes in rats fed an oil mixture rich in alpha-linolenic acid (18:3n-3) and borage oil rich in gamma-linolenic acid (18:3n-6) was therefore compared to that in rats fed an oil mixture rich in linoleic acid (18:2n-6) and a saturated fat (palm oil) in this study. Linseed oil served as the source of 18:3n-3 for the oil mixture rich in this octadecatrienoic acid and contained 30.6% 18:3n-3 but not 18:3n-6. Borage oil contained 25.7% 18:3n-6 and 4.5% 18:3n-3. Groups of seven rats each were fed diets containing 15% various fats for 15 d. The oxidation rate of palmitoyl-CoA in the peroxisomes was higher in rats fed a fat mixture rich in 18:3n-3 (3.03 nmol/min/mg protein) and borage oil (2.89 nmol/min/mg protein) than in rats fed palm oil (2.08 nmol/min/mg protein) and a fat mixture rich in 18:2n-6 (2.15 nmol/min/mg protein). The mitochondrial palmitoyl-CoA oxidation rate was highest in rats fed a fat mixture rich in 18:3n-3 (1.93 nmol/min/mg protein), but no significant differences in this parameter were seen among the other groups (1.25-1.46 nmol/min/mg protein). Compared to palm oil and fat mixtures rich in 18:2n-6, a fat mixture rich in 18:3n-3 and borage oil significantly increased the hepatic activity of carnitine palmitoyltransferase and acyl-CoA oxidase. Compared to palm oil and a fat mixture rich in 18:2n-6, a fat mixture rich in 18:3n-3, but not fats rich in 18:3n-6, significantly decreased 3-hydroxyacyl-CoA dehydrogenase activity. Compared to palm oil and a fat mixture rich in 18:2n-6, borage oil profoundly decreased mitochondrial acyl-CoA dehydrogenase activity, but a fat mixture rich in 18:3n-3 increased it. 2,4-Dienoyl-CoA reductase activity was significantly lower in rats fed palm oil than in other groups. Compared to other fats, borage oil significantly increased delt3,delta2-enoyl-CoA isomerase activity. Activity was also significantly higher in rats fed 18:2n-6 oil than in those fed palm oil. It was confirmed that both dietary 18:3n-6 and 18:3n-3 increased fatty acid oxidation activity in the liver. These two dietary octadecatrienoic acids differ considerably, however, in how they affect individual fatty acid oxidation enzymes.     

Alteration in 5'-nucleotidase activities and composition of liver and brain microsomes of developing rats fed different dietary fats

Four groups of male weanling rats were fed during three months, diets different in the nature of fats and the activity of 5' nucleotidase and fatty acid composition of brain and liver microsomes were studied. Group A were fed a standard commercial diet, group B a fat free-diet and group C and D a fat free-diet, containing respectively 10% of peanut-rapeseed oil and 10% of salmon oil. In brain and liver microsomes, 5'-nucleotidase activity increased throughout the development for all diets (except for the fat-free diet). Slight differences were found in rats fed the peanut-rapeseed oil diet compared to controls estimated at the same time. However, in animals fed the fish-oil diet, 5' nucleotidase had the highest activity in both brain and liver microsomes. Marked changes occurred in the fatty acid patterns of brain and liver microsomes among the various groups. The greatest alterations were found in the liver microsomes. In brain and liver microsomal membranes the fat-free diet induced an increase in monounsaturated fatty acids, an synthesis of eicosatrienoic acid, and a decrease in (n-6) and (n-3) polyunsaturated fatty acids. Animals fed a peanut-rapeseed oil and control diet showed similar fatty acid patterns in liver and brain microsomes. However, when rats were fed a fish-oil diet, the liver microsomal membranes were highly enriched in eicosapentaenoic and docosahexaenoic acids, and simultaneously there was a decrease in arachidonic acid. These results suggest that manipulation of the lipid environment influences 5'-nucleotidase activity by the interaction of the enzyme with specific membrane lipids.     

beta-carotene 15,15'-dioxygenase activity and cellular retinol-binding protein type II level are enhanced by dietary unsaturated triacylglycerols in rat intestines

The purpose of this study was to examine effects of dietary triacylglycerols on beta-carotene 15,15'-dioxygenase (EC 1.13.11.21) activity and cellular retinol-binding protein [CRBP (II)] in rats. Six groups of eight rats (7-wk old) were fed one of the following diets: standard (STD; 2.5% soybean oil), saturated (SFA; 15% hydrogenated soybean oil), monounsaturated (MUFA; 15% olive oil), polyunsaturated (PUFA; 15% soybean oil) or clofibrate (CLF; 2.5% soybean oil + 0.2% clofibrate) for 3 wk. The dioxygenase specific activities of the intestinal homogenates in the MUFA and PUFA groups fed the high fat diets were 2.4 times that of the STD group fed a low fat diet (P < 0.01), whereas the activities of the SFA and CLF groups were not significantly different from that of the STD group. The level of CRBP (II) in the intestine of the PUFA group was 1. 3-fold that of the STD group (P < 0.05), whereas there were no significant differences among the other groups. In a second experiment, the dioxygenase activity of rat intestine was followed over 3 wk of feeding the STD and PUFA diets. After the PUFA diet was consumed for 1 d, the activity was enhanced to 2.7 times the baseline level and remained thereafter at that high level, whereas the activity of the STD group remained at the low baseline level. Thus, dietary polyunsaturated triacylglycerols enhanced both beta-carotene 15,15'-dioxygenase activity and CRBP (II) level in rat intestine. These results suggest that the dioxygenase and CRBP (II) are regulated by the same mechanism involving long-chain fatty acids and their metabolites.     

Effects of dietary corn and olive oil versus coconut fat on biliary cholesterol secretion in rats

We have studied the effects of dietary corn and olive oil versus coconut fat on bile formation and fluidity of hepatic plasma membranes in rats. After 4 weeks of feeding the purified diets containing 9% (w/w) of the test fats, there was no difference in plasma cholesterol concentration between the dietary groups. The amount of free and esterified cholesterol in the liver was significantly higher in rats fed either corn oil or olive oil as compared with coconut fat. In the rats fed olive oil, but not in those fed corn oil this was associated with lower rates of biliary phospholipid excretion. Bile flow was not differently influenced by the three dietary fats. Hepatic plasma membranes of the rats fed corn or olive oil contained more cholesterol and less phospholipids than those on coconut fat, which was, however, not accompanied by changes in fluidity of the membranes. These results indicate that in rats the type of dietary fat can induce considerable changes in hepatic cholesterol metabolism without affecting plasma cholesterol concentrations, and without consistent effects on biliary cholesterol secretion.     

Mild traumatic brain injury does not modify the cerebral blood flow profile of secondary forebrain ischemia in Wistar rats

The rat hippocampus is hypersensitive to secondary cerebral ischemia after mild traumatic brain injury (TBI). An unconfirmed assumption in previous studies of mild TBI followed by forebrain ischemia has been that antecedent TBI did not alter cerebral blood flow (CBF) dynamics in response to secondary ischemia. Using laser Doppler flowmetry (LDF), relative changes in regional hippocampal CA1 blood flow (hCBF) were recorded continuously to quantitatively characterize hCBF before, during, and after 6 min of forebrain ischemia in either normal or mildly traumatized rats. Two experimental groups of fasted male Wistar rats were compared. Group 1 (n = 6) rats were given 6 minutes of transient forebrain ischemia using bilateral carotid clamping and hemorrhagic hypotension. Group 2 (n = 6) rats were subjected to mild (0.8 atm) fluid percussion TBI followed 1 h after trauma by 6 min of transient forebrain ischemia. The laser Doppler flow probe was inserted stereotactically to measure CA1 blood flow. The electroencephalogram (EEG) was continuously recorded. During the forebrain ischemic insult there were no intergroup differences in the magnitude or duration of the decrease in CBF in CA1. In both groups, CBF returned to preischemic values within one minute of reperfusion but traumatized rats had no initial hyperemia. There were no intergroup differences in the CBF threshold when the EEG became isoelectric. These data suggest that the ischemic insult was comparable either with or without antecedent TBI in this model. This confirms that this model of TBI followed by forebrain ischemia is well suited for evaluating changes in the sensitivity of CA1 neurons to cerebral ischemia rather than assessing differences in relative ischemia.     

Platelet-derived thromboxane A2 decreases microvascular perfusion after arterial repair

Previous work suggests that cod liver oil helps to protect the microcirculation from the consequence of thromboembolic events. The possibility that altered synthesis of thromboxane A2 accounts for the protective effects seen with cod liver oil was investigated in the present study. This was done using the combined thromboxane A2 synthetase inhibitor and thromboxane A2-prostaglandin H2 receptor blocker R68070 (Ridogrel). A standardized microvascular injury was inflicted on the right iliac artery of the rat to generate emboli. The downstream cremaster muscle was used to visualize the passage of the ensuing emboli and to assess the effects of this arterial injury on capillary perfusion and arteriole diameters. The number of visible emboli was not changed by either cod liver oil diet or Ridogrel administration. However, capillary perfusion was preserved by using cod liver oil (n = 7) and was significantly increased by using Ridogrel (n = 7) in comparison with untreated controls (n = 7) in which capillary perfusion was decreased because of the emboli. The administration of Ridogrel to cod liver oil-treated animals (n = 7) provided no additive benefit. The percentage change in A-2 vessel diameters in cod liver oil-treated (n = 7) animals was no different from the control group (n = 7). Ridogrel (n = 7), on the other hand, produced a significant increase in A-3 vessel (n = 21) diameters, but its effects were comparatively less in the cod liver oil-treated animals (n = 7). The formation of platelet aggregates (emboli) appears relatively independent of thromboxane A2 in the rat. Ridogrel is very effective in protecting the microcirculation, and these effects appear to be mediated by A-3 vasodilatation, which, therefore, is at least partially thromboxane A2-dependent. The positive effects of cod liver oil may be mediated by a mechanism that reduces thromboxane A2 synthesis, but further studies are necessary.     

Fat emulsions based on structured lipids (1,3-specific triglycerides): an investigation of the in vivo fate

PURPOSE: Structured lipids (1,3-specific triglycerides) are new chemical entities made by enzymatic transesterification of the fatty acids in the 1,3 positions of the triglyceride. The purpose of this study is to characterize structured lipids with either short chain fatty acids or medium chain fatty acids in the 1,3 positions with regard to their hydrophobicity, and investigate the in vivo fate in order to evaluate the potential of structured lipids as core material in fat emulsions used as parenteral drug delivery system. METHODS: The lipids were characterized by employing reversed phase high performance liquid chromatography. The biodistribution of radioactively labeled emulsions was studied in rats. RESULTS: By employing high performance liquid chromatography a rank order of the hydrophobicities of the lipids could be given, with the triglycerides containing long chain fatty acids being the most hydrophobic and the structured lipid with short chain fatty acids in the 1,3 positions the least. When formulated as fat emulsions, the emulsion based on structured lipids with short fatty acids in the 1,3 positions was removed slower from the general blood circulation compared to emulsions based on lipids with long chain fatty acids in the 1,3 positions. CONCLUSIONS: The type of core material influences the in vivo circulation time of fat emulsions.     

Biochemical and ultra-structural reactions to parenteral nutrition with two different fat emulsions in rats

OBJECTIVE: To compare the effects on fat metabolism and Kupffer cell morphology by total parenteral nutrition (TPN) with two different fat emulsions. DESIGN: Thirty-two male Sprague-Dawley rats, divided into three groups, were investigated. Rats fed orally were used as a reference group, and a group of rats receiving TPN with fat emulsions containing pure long-chain triglycerides (LCT) was compared to a group of rats receiving fat emulsions containing both long-chain triglycerides and medium-chain triglycerides (MCT/LCT). The TPN regimens were equicaloric and administered continuously via a jugular catheter for 10 days. INTERVENTIONS: After suffocation, blood of the rats was collected for the determination of serum lipids. Epididymal fat and heart were collected for the analysis of lipoprotein lipase (LPL) activities, and liver specimens were saved for analyses of hepatic triglyceride concentration, as well as activities of hepatic lipase (HL) and lysosomal enzymes. Light and electron microscopy were used for examination of the Kupffer cell reaction. RESULTS: Directly after termination of parenteral feeding, the levels of serum triglycerides and high density lipoprotein (HDL) triglycerides were higher in the MCT/LCT group than in the LCT group, while no differences concerning cholesterol and phospholipid concentrations were found. No significant difference in liver steatosis was found between the two TPN groups. Comparison of the TPN groups showed that the MCT/ LCT group had significantly decreased LPL activity in adipose tissue, while the LCT group had significantly increased LPL activity in the heart. The activity of HL was low in both groups, but significantly lower in the LCT group. Lipid accumulation and an increased number of lysosomes were found in all Kupffer cell when TPN with LCTemulsions was used. Moreover, TPN induced a pronounced increase in various liver lysosomal enzyme activities, but there was no notable difference between LCT and MCT/LCT effects. CONCLUSIONS: Compared to treatment with pure LCTemulsions, treatment with MCT/LCT emulsions evoked weaker biochemical reactions in terms of lower activity of lipoprotein lipase in fat and heart together with higher serum and HDL triglyceride levels. Morphological signs of increased Kupffer cell activity such as the appearance of multiple lysosomes and fat vacuoles in the cytoplasm followed treatment with pure LCT emulsions. However, both TPN groups showed a marked increase in activities of liver lysosomal enzymes.     

Influence of dietary fats upon systolic blood pressure in the rat

Studies were performed to determine whether feeding diets with differing fatty acid content and composition had an influence on systolic blood pressure in the rat. Weanling male rats were fed standard laboratory chow (2.9% fat in total), or synthetic diets (10% fat in total) containing fish oil, butter, coconut oil or corn oil, for 5 weeks. Coconut oil and butter diets were rich in saturated fatty acids, whilst fish oil and corn oil were rich in the n-3 and n-6 unsaturated fatty acids respectively. Systolic blood pressure was measured using an indirect tail-cuff method at the end of the feeding period, and compared to a group of weanling rats. Feeding the different diets did not alter the growth of the rats, so all animals were of similar weights at the time of blood pressure determination. Control (chow fed) animals, at nine weeks of age, had higher systolic blood pressures than the weanling, baseline control group. Fish oil fed rats had similar pressures to the chow fed rats. Corn oil fed rats had significantly lower systolic pressures than the controls. The rats led the diets rich in saturated fatty acids (butter and coconut oil) had significantly higher blood pressures than all other groups. Systolic blood pressure was found to be significantly related to the dietary intakes of saturated and unsaturated fatty acids. The dietary intake of linoleic acid was significantly higher in corn oil fed rats than in other groups. Systolic blood pressure was inversely related to linoleic acid intake. Feeding a diet rich in saturated fatty acids significantly increases blood pressure in the rat. A high intake of n-6 fatty acids, and in particular linoleic acid, appears to have a hypotensive effect. Prenatal exposure of the rats to a maternal low protein diet, abolished the hypertensive effects of the coconut oil diet and the hypotensive effect of the corn oil diet upon young adult females. The intrauterine environment may, therefore, be an important determinant of the effects of these fatty acids on blood pressure in later life.     

Effect of the quality characteristics of the fatty component of the diet on the fatty acid makeup of the erythrocytic and thrombocytic membranes in healthy persons

Practically healthy males received rations in which principal sources of fat in the descending order were butter, sunflower and mustard oil. The influence of qualitative properties of the ration's fat on the lipids metabolism in the plasma and the coefficient of the metabolization effectiveness of essential fatty acids (CEM) of the food into the membranes lipids was studied. The CEM was calculated by studying the fatty acids composition of the erythrocytes and thrombocytes stroma. Inclusion in the ration of butter alone, raised the cholesterol level, a fall of the plasma phospholipids level and a significant drop of the CEM. Substitution of sunflower oil for butter led to normalization of these figures. Mustard oil had no effect. Changes in the CEM of the erythrocytes stroma proceeded slowly, significant differences having been discovered only after 6 weeks of the butter consumption. The thrombocytes CEM changed quickly, a stable fatty acids composition of thrombocytes with this ration being established by the end of the 2nd week. The qualitative properties of the ration's fat exercise a sufficiently strong influence on the effective metabolization of fatty acids in the food into the lipid structures of the erythrocytes and thrombocytes membranes in a healthy subject, it being characterized by the CEM changes.     

Influence of cholesterol and fat feeding on hepatic lysosomal enzymes in guinea pigs

The activity of four lysosomal enzymes have been examined in liver cytoplasmic extract from guinea pigs fed three different diets: a) an ordinary diet, low in fat, high in carbohydrates; b) a semisynthetic diet containing 10% cottonseed oil (by weight) without and c) with 1% cholesterol. The cholesterol content in the liver was similar in control-fed and fat-fed animals, while there was a 10-fold increase in cholesterol + fat-fed animals, and most of this cholesterol was present as ester. We observed increased activity of beta-glucuronidase, beta-acetyl-glucosaminidase and cathepsin D during fat cholesterol feeding (diet c) while the activity of acid phosphatase decreased compared to control-fed animals. These findings probably mirror the increased hepatic accumulation of lipids and lipoproteins observed in cholesterol + fat-fed guinea pigs.     

The 2nd decree on prevention and control of tuberculosis; new tasks and perspectives for pneumonology in GDR (AUTHOR''S TRANSL)

Tests made on adult albino rats kept for two weeks on isocaloric rations with an equal content of protein, but differing in that of fat and dissimilar in the fatty acids composition and the methionine level evidenced that in the event of a prolonged muscular activity the authors find rations with a not too high fat content (30 and less per cent of the aggregate caloricity), but sufficiently rich in linolic acid and methionine more adequate. Failure to comply with these conditions causes an inferior utilization of lipids during muscular activity and slowing down of the restitution processes at the time of rest. The character of the ration has no material effect on the mobilization of carbohydrates and lipids during muscular activity.     

The murine Spam1 gene: RNA expression pattern and lower steady-state levels associated with the Rb(6.16) translocation

We investigated the effects of type of dietary fat and phenobarbital on gamma-glutamyl transpeptidase-positive foci development. Four groups of six female Sprague-Dawley rats were initiated with diethylnitrosamine (15 mg/kg) at 24 hours of age. After weaning, they were fed nutritionally complete semipurified diets containing 15% corn oil or 5% corn oil + 10% fish oil and supplemented with 5,000 ppm vitamin E with or without phenobarbital (500 ppm) for three months. Dietary fish oil significantly increased hepatic phospholipid eicosapentaenoate and docosahexaenoate concentrations and decreased arachidonate concentration compared with 15% corn oil (p < 0.05). Corn oil (15%) significantly increased hepatic prostaglandin F2 alpha concentration compared with 10% fish oil (p < 0.05). Phenobarbital significantly stimulated glutathione S-transferase activity in both dietary fat groups (p < 0.05). In the absence of phenobarbital, type of dietary fat showed no effect on hepatic gamma-glutamyl transpeptidase-positive foci development. However, in the presence of phenobarbital, 15% corn oil significantly enhanced gamma-glutamyl transpeptidase-positive foci development compared with 10% fish oil (p < 0.05). Phenobarbital showed a strong tumor-promoting action in both dietary groups. In conclusion, there was an interaction between type of dietary fat and phenobarbital on gamma-glutamyl transpeptidase-positive foci development during hepatocarcinogenesis in rats.     

Human milk lipases and their possible role in fat digestion

Human milk contains two lipases. One is a lipoprotein lipase with properties similar to the lipoprotein lipases that participate in the metabolism of blood plasma lipoproteins in several tissues. This enzyme is present in high activity in the lactating mammary gland where it facilitates the uptake of triglyceride fatty acids from the blood lipoproteins for production of milk lipids in the gland. The high activity of this enzyme in milk probably represent leakage of enzyme from the gland. This lipase is not stable at pH below 5 or in intestinal contents and it is unlikely that it participates in intestinal fat digestion. Its activity varies widely between individual milk samples, and there is a high correlation between its activity and the development of hydrolytic rancidity in the milk on storage. The other lipase is present in the milk in an inactive form which is activated by bile salts. This lipase is present in milk from primates but not in milk from lower animals. Human milk contains enough of this lipase to hydrolyze the milk lipids almost completely in less than half an hour at the pH and the bile acid and salt concentrations found in the small intestine of the human infant. It is probable that it increases the efficiency of milk fat absorption. The enzyme has a rather wide substrate specificity and may also act on other lipid substrates than triglycerides. In contrast to pancreatic lipase it hydrolyses all three ester bonds in a triglyceride. This may affect the physical chemistry of the lipids in the intestinal contents as well as their absorption and further metabolism in the musoca.     

Fat elimination during intraoperative autotransfusion: an in vitro investigation

Intraoperative autotransfusion of scavenged blood is an established method to reduce the need for perioperative homologous blood transfusion. However, if fat particles contaminate blood suctioned from the wound site, no reliable method is available to remove them during the washing and concentration of the recycled blood. A new generation of autotransfusion devices (e.g., continuous autotransfusion system [CATS]), based on separation chambers used in cell separators or plasmapheresis devices, allows continuous procession of the collected blood, in contrast with the discontinuous process used in conventional autotransfusion devices such as the Cell Saver 5. Theoretically, the continuous system should be more efficient than the discontinuous system in eliminating fat. Outdated, 36-day-old packed red blood cells, 600 mL, were mixed with 500 mL of lactated Ringer's solution and 200 mL of soya oil. Soya oil was used because it has a fatty acid composition similar to that of fat found in bone marrow. The blood mixture was then washed and concentrated by using either the CATS or the Cell Saver 5. Six samples were processed by each device. The CATS eliminated the soya oil (200 mL) completely, whereas the Cell Saver 5 delivered 30.3 +/- 7.8 mL soya oil into the retransfusion bag. The new generation of autotransfusion devices allows complete removal of fat particles. IMPLICATIONS: Autotransfusion devices serve to wash and retransfuse blood scavenged from the wound site. However, they cannot completely remove fat particles. This in vitro investigation showed that a new device completely removes fat particles and thus prevents retransfusion of fat.     

Heart and red blood cell antioxidant status and plasma lipid levels in the spontaneously hypertensive and normotensive Wistar-Kyoto rat

Heart and red blood cell endogenous antioxidant status and plasma lipids were investigated in hypertensive, 14-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats fed a standard commercial rat chow. Specific heart and red blood cell antioxidant enzyme activities, as well as the susceptibility of tissues to H2O2-induced glutathione (GSH) depletion and lipid peroxidation, were measured. Systolic blood pressure in SHR was greater than in WKY rats at 13 weeks of age (197 +/- 12 vs. 132 +/- 14 mmHg (1 mmHg = 133.3 Pa); p < or = 0.05), confirming the presence of hypertension in SHR. Red blood cell catalase (CAT) and superoxide dismutase (SOD) activities were greater (p < or = 0.05) in SHR than WKY rats. Red blood cell CAT activity was positively correlated (r = +0.634; p = 0.026) with SOD, which in turn was correlated (r = +0.709; p = 0.049) with systolic blood pressure. Heart SOD activity was higher (p < or = 0.05) in SHR, while glutathione reductase (GSSG-Red) activity was lower (p < or = 0.05) than in WKY rats. This reduced ability to recycle GSH in the heart coincided with greater (p < or = 0.05) levels of H2O2-induced lipid oxidation products in SHR. Plasma total cholesterol and triacylglycerol levels were lower (p < or = 0.05) in SHR than WKY rats, with no visible signs of atherosclerosis in either SHR or WKY rats. In summary, hypertension in SHR was associated with alterations in antioxidant enzyme profiles of red blood cells and heart, with the latter showing an increased susceptibility to in vitro lipid oxidation. Although hypertension is a recognized factor in the development of human atherosclerosis, spontaneously hypertensive rats did not exhibit signs of aortic plaque, reflecting the resistance of this species to the development of atherosclerosis.     

Effects of dietary fatty acid composition on basal and hormone-stimulated hepatic lipogenesis and on circulating lipids in the rat

Thirty male rats were randomly assigned to one of three dietary groups in which the source of dietary fat was either a mixed oil, maize oil or fish oil. Effects of dietary fatty acid composition on in vitro rates of [U-14C]glucose incorporation into hepatic total lipids and into hepatic triacylglycerol were measured under basal, insulin (4 nM)-, gastric inhibitory polypeptide (GIP; 6 nM)- and insulin + GIP (4 nM + 6 nM)-stimulated conditions. Effects of the three diets on postprandial plasma triacylglycerol, cholesterol, insulin and GIP concentrations were also measured. The fish-oil diet decreased rates of basal glucose incorporation into hepatic total lipids (P < 0.05) and hepatic triacylglycerol, (P < 0.01) compared with the mixed-oil diet. The presence of insulin + GIP in the incubation medium stimulated glucose incorporation into hepatic total lipids in the maize-oil (P < 0.01) and fish-oil groups (P < 0.05), as well as into hepatic triacylglycerol in the maize-oil group (P < 0.005). In addition, the fish-oil diet decreased postprandial plasma triacylglycerol levels compared with both other dietary groups (P < 0.05 both cases), and the mixed-oil diet markedly increased postprandial plasma insulin levels compared with the other dietary groups (P < 0.001).