Lipid Content Of Plasma Research Articles

Dynamics of lipid droplets in the endometrium and fatty acids and oxylipins in the uterine lumen, blood, and milk of lactating cows during diestrus

Our objective was to investigate the lipid content of uterus, blood plasma, and milk at early, mid, and late diestrus. Lactating cows (n = 30) had the estrous cycle and ovulation synchronized by administration of exogenous hormones. Cows were blocked by parity and assigned randomly to receive transcervical uterine flushing and biopsy on d 5 (early diestrus), 10 (mid diestrus) or 15 (late diestrus) of the estrous cycle. Flushing and endometrial biopsy were performed in the uterine horn ipsilateral to the corpus luteum. The recovered flushing was used for analyses of lipid composition by liquid chromatography-tandem mass spectrometry and the biopsy was used for investigation of lipid droplet abundance in endometrial cryosections using a neutral lipid fluorescent dye. In addition, blood and milk samples were collected from all cows on d 5, 10, and 15. All blood samples were used to measure the concentration of progesterone in plasma, and all milk samples were used to determine milk composition. Subsamples of blood plasma and milk were also used to evaluate the composition of fatty acids and oxylipins using the same methodology used for uterine flushing samples. The abundance of lipid droplets in the endometrium increased 1.9-fold from d 5 to 10, and 2-fold from d 10 to 15. Concentration of long-chain fatty acids and oxylipins in uterine flushing were, on average, 2.2 and 2.5 times greater in samples collected on d 15 compared with those collected on d 5 and 10. These differences were not observed in blood and milk, suggesting that accumulation of fatty acids and oxylipins in the uterus is regulated locally. In addition to concentration, the profile of individual fatty acids and oxylipins in uterine lumen changed substantially during diestrus. The main categories with increased abundance at late diestrus were mono- and polyunsaturated fatty acids, and oxylipins derived from arachidonic acid, dihomo-γ-linolenic acid, and docosahexaenoic acid. In conclusion, fatty acids and oxylipins accumulate in the uterine lumen during diestrus and might work as a mechanism to supply these lipids to the developing conceptus at late diestrus, when the onset of elongation occurs and substantial synthesis of biomass and cell signaling by lipid mediators are required.

Spectrophotometry and Ultracentrifugation for Measurement of Plasma Lipids in Dogs with Diabetes Mellitus.

BackgroundThere are conflicting reports of plasma lipoprotein lipid content in dogs with diabetes mellitus (DM).ObjectivesTo determine lipoprotein lipid content of plasma of dogs with DM by spectrophotometry and ultracentrifugation; to compare lipoprotein lipid content in diabetic and healthy dogs; and to quantify apolipoprotein B‐100 (ApoB) in dogs with DM.Animals22 dogs with DM and 9 healthy dogs.MethodsCross‐sectional study. Triglyceride (TG), total cholesterol (TC), and high‐density lipoprotein cholesterol (HDL‐C) concentrations were measured by spectrophotometry. Very low‐density lipoprotein cholesterol (VLDL‐C) and low‐density lipoprotein cholesterol (LDL‐C) concentrations were calculated after ultracentrifugation. Non‐HDL‐C cholesterol was calculated by subtracting HDL‐C from TC. ApoB was quantified by ELISA. The Mann‐Whitney test was used for comparison of median lipoprotein concentrations, and Spearman's correlation was used to assess associations between ApoB and lipoprotein fractions.ResultsAll values are reported in mg/dL. Median TG (122), TC (343.5), HDL‐C, (200), VLDL‐C, (27) LDL‐C (68), non‐HDL‐C (114), and ApoB (320) were significantly higher in dogs with DM, compared to healthy dogs (57, 197, 168, 12, 16, 31, and 258, respectively, P‐values 0.0079, <0.001, 0.029, 0.011, <0.001, <0.001, 0.025, respectively). A significant association was found between ApoB and LDL‐C (Spearman's rho = 0.41, P = 0.022) and between ApoB and non‐HDL‐C (Spearman's rho = 0.40, P = 0.027).Conclusions and Clinical ImportanceDyslipidemia of dogs with DM is characterized by pronounced increases in LDL‐C and non‐HDL‐C concentrations, although all lipoprotein fractions are significantly increased. Knowledge of specific lipoprotein fraction alterations in dogs with DM can enhance treatment options for diabetic dyslipidemia in dogs.

Lipid peroxidation and state of the erythron in newborn rats under normal conditions and impairment of sensorimotor reflexes.

Specimens with a stereotypic sensorimotor deficit were revealed among newborn rats due to abnormalities in prenatal ontogeny and birth stress. Genetically determined differences in the total lipid content of blood plasma were found in Wistar and August rat pups. Hence, LPO processes were shown to differ in these animals. August rats with intense lipid metabolism were characterized by higher activity of LPO in comparison with Wistar rats. The increase in LPO was associated with a relatively low activity of antioxidant enzymes. Impairment of sensorimotor reflexes in newborn Wistar and August rats was accompanied by suppression of the erythron and activation of extravascular hemolysis.

Lipaemic plasma induces haemolysis in resuspended red cell concentrate

We investigated whether haemolysis in red cells suspended in plasma was affected by the lipid content and/or methylene blue (MB) treatment of fresh-frozen plasma (FFP). We also investigated whether haemolysis was affected by the conditions under which lipaemic plasma was stored. Study 1: Visibly lipaemic (n = 22) or nonlipaemic FFP (n = 24) units were thawed, pooled and split into identical pairs, one of which was MB treated. These units were used to resuspend red cell concentrates (RCC) and tested for haemolysis immediately and after 24 and 48 h of storage at 2-6°C. Study 2: Fresh plasma was aliquoted into 15-ml tubes and stored in one of four ways as follows: room temperature; 2-6°C; frozen and thawed; or twice frozen and thawed. A sample of RCC was resuspended in each of these plasmas and haemolysis measured after 2 h. Study 3: Plasma was divided into 15-ml tubes and stored as in study 2 followed by storage left standing upright in a refrigerator (2-6°C) for 24 h (with the exception of the room temperature sample). Plasma was separated into top, middle and bottom fractions and used to resuspend RCC that were assessed for haemolysis after 2 h. The levels of haemolysis in RCC were immediately greater when suspended in lipaemic plasma (0·70 ± 0·53% v 0·05 ± 0·06% for nonlipaemic plasma), which increased further on subsequent storage for 48 h (1·22 ± 0·40% v 0·15 ± 0·14% for nonlipaemic plasma). This was irrespective of whether plasma was MB treated. Lipaemic plasma stored frozen and then thawed resulted in the greatest haemolysis. In lipaemic plasma stored at 2-6°C, the chylomicron-rich top fraction caused the highest level of haemolysis. Haemolysis in red cells is increased in those suspended in lipaemic plasma and is dependent upon the storage conditions of that plasma prior to suspension. These data are relevant to the choice of plasma used to suspend red cells for neonatal exchange transfusion.

Effect of Dietary α-Linolenic Fatty Acid Derived from Chia when Fed as Ground Seed, Whole Seed and Oil on Lipid Content and Fatty Acid Composition of Rat Plasma

Coronary heart disease (CHD) is the most common cause of death in the Western world. In both the USA and the EU it accounts for over 600,000 deaths yearly. Early data showing the benefits n–3 fatty acids provide in preventing CHD disease were obtained using 20:5n–3 and 22:6n–3 fatty acids derived from fish. Recently, however, it has been shown that reduced risks of CHD and other cardiovascular diseases are found with 18:3n–3 fatty acid as well. To determine if 18:3n–3 fatty acids positively influence plasma composition, 32 male Wistar rats were fed ad libitum four isocaloric diets with the energy derived from corn oil (T₁), whole chia seed (T₂), ground chia seed (T₃), or chia oil (T₄) for 30 days. At the end of the feeding period the rats were sacrificed, and blood samples were analyzed to determine serum CHOL, HDL, LDL, TG content, hemogram, and fatty acid composition. Chia decreased serum TG content and increased HDL content. Only with the T₂ diet was TG significantly (p < 0.05) lower, and only with the T₃ diet was HDL significantly (p < 0.05) higher, than the control diet. Chia significantly (p < 0.05) increased the 18:3n–3, 20:5n–3 and 22:6n–3 plasma contents compared to the control diet, with no significant (p < 0.05) difference among chia diets detected. Significant (p < 0.05) improvement in n–6/n–3 fatty acid ratio was observed for all chia diets when compared to the control.

Coenzyme Q10 in maternal plasma and milk throughout early lactation

In contrast to other lipophilic antioxidants Coenzyme Q10 originates from food intake as well as from endogenous synthesis. The CoQ10 concentration and lipid content of maternal milk and maternal plasma was investigated during early lactation. Breast milk was obtained from 23 women: A: colostrums (24-48 hours postpartum), B: transitional milk (day 7 pp), C: mature milk (day 14 pp). At the same time capillary blood specimens were collected. Milk and plasma were stored at -84 degrees C until CoQ10 was analysed after hexane extraction by HPLC. The lipid content was determined by PAP-analysis of cholesterol. The plasma content of CoQ10 was the highest soon after delivery (A: 1.29, B:1.20, C:1.07 pmol/microl; Wilcoxon p < 0.05 A vs. C and B vs. C). This tendency was still evident after lipid-adjustment (A:209, B:180, C:175 micromol CoQ10/mol cholesterol; Wilcoxon p < 0.01 A vs. B and C). The level of CoQ10 in milk showed a gradual decline during early lactation (A:0.80, B:0.57, C:0.44 pmol/microl; Wilcoxon p < 0.02 A vs. B and C). After lipid-adjustment this tendency became even more evident (A: 137, B:86, C:67 micromol CoQ10/mol cholesterol; Wilcoxon p < 0.002 A vs. B and C, p < 0.05 B vs. C). The content of CoQ10 in plasma and milk showed a correlation with early milk (Spearman p < 0.005) but not with mature milk. Although lipid content is low the colostrums is a rich source for the lipophilic antioxidant CoQ10.

Influence of dietary long-chain n-3 fatty acids from Menhaden fish oil on plasma concentrations of α-tocopherol in geriatric Beagles

To determine effects of dietary n-3 fatty acids from Menhaden fish oil on plasma alpha-tocopherol concentrations in Beagles. 32 female Beagles. For 82 days, dogs were fed diets that contained 1 of 2 ratios of n-6:n-3 fatty acids (40:1 [low n-3] and 1.4:1 [high n-3]) and 1 of 3 concentrations of all-rac-alpha-tocopheryl acetate (low, 17 mg/kg of diet; medium, 101 mg/kg; and high, 447 mg/kg) in a 2 X 3 factorial study. Diets high in n-3 fatty acids significantly increased total content of n-3 fatty acids in plasma (17.0 g/100 g of fatty acids), compared with low n-3 diets (2.02 g/100 g of fatty acids). Mean +/- SEM plasma concentration of cholesterol was significantly lower in dogs consuming high n-3 diets (4.59 +/- 0.48 mmol/L), compared with dogs consuming low n-3 diets (5.71 +/- 0.48 mmol/L). A significant interaction existed between the ratio for n-6 and n-3 fatty acids and amount of alpha-tocopheryl acetate in the diet (plasma alpha-tocopherol concentration expressed on a molar basis), because the plasma concentration of alpha-toco-pherol was higher in dogs consuming low n-3 diets, compared with those consuming high n-3 diets, at the 2 higher amounts of dietary alpha-tocopheryl acetate. Plasma alpha-tocopherol concentration expressed relative to total lipid content did not reveal effects of dietary n-3 fatty acids on concentration of alpha-tocopherol. Plasma alpha-tocopherol concentration is not dependent on dietary ratio of n-6 and n-3 fatty acids when alpha-tocopherol concentration is expressed relative to the total lipid content of plasma.

Changes in lipid content of fowl spermatozoa after liquid storage at 2 to 5°C

Quantitative and qualitative changes may occur in the lipids of spermatozoa during in vitro storage of gametes and may indicate possible degradations occurring within the cells under these conditions. The aim of the present study was to investigate such changes. The motility, viability, morphological integrity and lipid content were measured in fowl semen stored for 48 h at 2 to 5°C and diluted 11 in Beltsville Poultry Semen Extender (BPSE) under aerobic agitation. The total lipid content of spermatozoa decreased (P<0.05) from 820 to 620 μg/10 9 cells over 48 h. There was no significant evolution in the total lipid content of seminal plasma (1000 to 850μg/10 9 cells). The proportion of phospholipids in spermatozoa decreased from 75 to 60% of the total lipids. Among the phospholipids, the proportions of phosphatidylcholine, phosphatidylethanolamine and sphingomyelin decreased (P<0.05) from 58, 13 and 10% at 0 h to 42, 10 and 9% at 48 h, respectively. In contrast, lysophosphatidylcholine, which was marginally represented at 0 h (2%), increased considerably (24%) at 48 h. During the same period, the proportion of motile spermatozoa decreased from 87.5 to 46% and the proportion of viable and morphologically normal cells decreased from 84 to 48%. These results indicate the occurrence of lipid lysis, peroxidation and /or endogenous metabolism able to modify the structure of the spermatozoal membranes and to alter their metabolism and fusion abilities.

Plasma oxygen during cardiopulmonary bypass: a comparison of blood oxygen levels with oxygen present in plasma lipid.

1. Although not often appreciated, it is a fact that molecular oxygen is more soluble in lipids than in aqueous solution. We have recently developed a method to monitor oxygen within the lipid content of plasma. Monitoring plasma oxygen is one essential element during open heart surgery using a cardiopulmonary bypass pump and oxygenator. Currently oxygen is monitored electrochemically and is based upon monitoring the partial pressure of oxygen in a gas equilibrated with whole blood. 2. To determine the relative importance of lipid-associated oxygen in blood and assess the potential use of such a measurement we present comparisons of changes in oxygen associated with whole blood and lipid content of plasma before, during and after cardiac surgery. 3. In a limited number of patients studied (n = 28), aged between 34 and 86 years, oxygen in lipid increased with decreased extracorporeal blood temperature during cardiopulmonary bypass, increased in proportion to oxygen supplied and appeared to be a better monitor of oxygen than conventional electrochemical systems currently in use. Oxygen associated with whole blood and plasma lipid was markedly below normal on aortic declamping after cardiopulmonary bypass, suggesting an hypoxic episode at this point. Levels of oxygen in the lipid phase of plasma returned to normal presurgical values 6-8 h after surgery. 4. Calculation of the concentration of lipid-associated oxygen present in plasma suggests that plasma lipids contain up to 25% of that typically ascribed to haemoglobin. Thus, we suggest that monitoring lipid-associated oxygen may prove a better alternative to current methods of measuring oxygen status. Furthermore, we suggest that plasma lipid is a hitherto unsuspected pool of circulating oxygen which may play a significant role in tissue oxygen supply.

Effect of dietary fish oil supplementation on peroxidation of serum lipids in patients with non-insulin dependent diabetes mellitus

Lipid peroxidation may be important in the development of cardiovascular disease, a common cause of mortality and morbidity in non-insulin dependent diabetes mellitus (NIDDM). We assessed the degree of lipid peroxidation by measuring plasma malondialdehyde, as thiobarbituric acid reacting substances (TBARS), in 23 non-insulin dependent diabetic patients. Plasma levels of lipid standardised α-tocopherol (vitamin E), lipid content of whole plasma and lipoprotein fractions, glycosylated haemoglobin, glycosylated low density lipoprotein (LDL) and fasting blood glucose were also measured. On completion of the baseline studies patients randomly received either fish oil or matching olive oil capsules in a double blind crossover fashion for 6 weeks followed by a 6 week washout period and a final 6 week treatment phase. Studies, identical to the initial baseline studies, were performed at the end of the active treatment periods at 6 and 18 weeks. Treatment with olive oil did not change levels of TBARS, vitamin E or indices of glycaemic control compared with baseline. Total cholesterol and triglyceride (TG) content of plasma and lipoprotein fractions were not significantly altered. Treatment with fish oil resulted in elevation of TBARS ( P < 0.001) and reduction of vitamin E ( P < 0.01) compared with baseline and olive oil treatment. Plasma cholesterol was unchanged. A reduction in plasma TG compared with baseline occurred but failed to reach significance ( P = 0.07). Changes in apo B containing lipoproteins induced by fish oil failed to reach significance. No significant changes were observed in the concentration or composition of high density lipoprotein (HDL). Fish oil treatment showed no change in glycaemic control as assessed by glycosylated haemoglobin and LDL although a rise in fasting blood glucose just failed to reach significance ( P = 0.06). Lipid peroxidation in NIDDM can be exacerbated by dietary fish oil. This potentially adverse reaction may limit the therapeutic use of fish oils in such patients.

Increased lipid binding to thrombi in coronary artery disease. Findings in patients without premedication in native (not anticoagulated) test systems.

Thrombi and clots were produced from native (i.e., not anticoagulated) platelet-rich and platelet-poor plasma from patients with coronary artery disease and control subjects who had not taken any medication known to influence plasma lipids, coagulation, or platelet aggregation. The clotting times were recorded, and the lipid content of clots, thrombi, platelets, plasma, and high density lipoprotein was analyzed. Thrombi produced from native platelet-rich plasma were 46% heavier in coronary artery disease patients and contained about 20% more phospholipids and free cholesterol and about twice the amount of triglycerides and esterified cholesterol in both absolute and relative amounts with respect to the corresponding lipids of plasma plus platelets. The elevated content of lipids not only increases the size of the thrombi but also changes their quality because of an increased content in plasmatic lipids, as platelets contain only trace amounts of triglycerides and cholesterol esters. In agreement herewith, fibrinogen and maximal amplitude on the thrombelastogram were increased in coronary artery disease patients, whereas the thrombus-forming time and clotting times of platelet-poor and platelet-rich plasma were shortened, indicating accelerated coagulation and activation of platelets. Analysis of these results suggests a disturbed interrelation in coronary artery disease between lipids and hemostasis, in which platelets, high density lipoprotein, and lipoproteins rich in triglycerides and cholesterol esters may play a role.

Iron Intake Influences Essential Fatty Acid and Lipid Composition of Rat Plasma and Erythrocytes

In view of the clinical importance of iron deficiency as well as the known role of iron in stearic acid desaturation, the effects of higher or lower iron intake on fatty acid composition of blood and liver in the rat were studied. Male Sprague-Dawley rats were fed purified diets that contained iron at 12, 27 or 237 mg/kg. After 12 wk the lipid and fatty acid composition of plasma, erythrocytes and liver was analyzed. Linoleic acid in plasma phospholipids and triacylglycerols was higher, but arachidonic acid was lower in the group fed 12 mg/kg iron than in the groups fed 27 or 237 mg/kg iron. Liver fatty acid and lipid composition was not different between groups. In the group fed 237 mg/kg iron, plasma cholesterol and triacylglycerols were 150%, erythrocyte cholesterol was 137% and erythrocyte phospholipids were 148% of levels in the rats fed 27 mg/kg iron. The fatty acid data suggest a mild impairment in essential fatty acid metabolism in moderately iron-deficient rats. The lipid data suggest a significant alteration in the total lipid content of plasma and erythrocytes of iron-supplemented rats.

Membrane lipid changes in erythrocytes, liver and kidney in acute and chronic experimental liver disease in rats

Lipid molecules in lipoprotein surfaces exchange with their counterparts in cell plasma membranes. In human or experimental liver disease, plasma lipoprotein surfaces are enriched in cholesterol and deficient in arachidonate; corresponding alterations occur in membrane lipids of erythrocytes. To determine whether similar changes take place in membranes of nucleated cells, the lipid content of plasma and of erythrocyte, liver and kidney membranes was measured in rats with acute (3-day) galactosamine-induced hepatitis or chronic (3-week) biliary obstruction. In both models of liver injury the cholesterol:phospholipid ratio in plasma and in erythrocytes was significantly increased ( P < 0.001). Although this ratio was also elevated in liver and kidney microsomes, only in liver microsomes of obstructed rats was the increase significant ( P < 0.001). However, the cholesterol:phospholipid ratio of kidney brush-border membranes, was significantly higher in bile-duct-ligated rats; presumably, compensating mechanisms limit cholesterol accumulation in intracellular membranes. Kidney brush-border membranes from obstructed rats were deficient in arachidonate as were plasma and erythrocytes. However, arachidonate levels were unchanged in kidney microsomes; renal Δ 6-desaturase, the rate-limiting enzyme in the conversion of linoleic acid to arachidonic acid, was increased by 50% ( P < 0.001) and may have counteracted a reduced supply of exogenous lipoprotein arachidonate. We conclude that in experimental liver disease lipoprotein-induced lipid abnormalities can occur in renal membranes, although compensatory mechanisms may operate; the alterations seen, cholesterol accumulation and arachidonate depletion, would be expected to interfere with sodium transport and prostaglandin production, respectively. Our findings support the hypothesis that lipid abnormalities in kidney membranes contribute to the renal dysfunction which is a frequent complication of human liver disease.

Increased plasma and tissue levels of vitamin E in the spontaneously diabetic BB rat

Increased plasma and tissue levels of vitamin E were found in spontaneously diabetic BB rats (D) as well as asymptomatic/diabetes-prone BB rats (AD) in comparison to levels in non-diabetic control rats (ND). Treatment of D rats with insulin for 30 days returned plasma and tissue values of vitamin E to control levels. The changes reported here could not be explained solely on the basis of variations in total lipid content of plasma. These data suggest the metabolism of vitamin E is altered in aymptomatic and spontaneously diabetic BB rats and this alteration returns to control values following insulin treatment. Furthermore, it might be speculated that these data indicate a relationship between vitamin E and insulin.

Effects of Several Types of Dietary Fibers on Lipid Content in Liver and Plasma, Nutrient Retentions and Plasma Transaminase Activities in Force-Fed Growing Chicks

Lipid content and lipid composition of liver and plasma, nutrient retention and plasma transaminase activity were determined in White Leghorn male chicks that were force-fed a purified high energy diet supplemented with or without dietary fiber for 13 days. Six types of dietary fibers, cellulose-A and -B, rice hull, rice hull NDF, alfalfa meal and peanut hull NDF, and a synthetic fiber, polyamide, were supplemented at the level of 4% in each experimental diet. Liver lipid content was significantly depressed by the cellulose, rice hull NDF, alfalfa meal and polyamide diets. Plasma lipid concentration was significantly reduced by the cellulose, alfalfa meal and polyamide diets but was not influenced by the rice hull, rice hull NDF and peanut hull NDF diets. Retentions of energy, nitrogen and lipid were not depressed by addition of the dietary fibers. These find ings suggest that the depression of liver lipid content by feeding certain dietary fibers is independent of the reduction of nutrient absorption in the force-fed growing chicks. Activities of glutamate-oxalacetate transaminase and glutamate-pyruvate transaminase were elevated by force-feeding and were reduced by feeding the cellulose, rice hull NDF, alfalfa meal and polyamide diets. It is suggested that dietary fibers are effective not only in reducing the liver lipid content but also in alleviating liver dysfunction induced by force-feeding in growing chicks, although mechanism of action of each dietary fiber may not be identical. J. Nutr. 110: 1112-1121,

Response of lipogenic enzymes and plasma lipids to starvation and refeeding in the adult Japanese quail (Coturnix coturnix japonica).

Adult male Japanese quail (Coturnix coturnix japonica) were starved for 48 or 60 h and then refed for either 24 or 48 h. Weight and lipid content of carcass and livers were determined, as was the lipid content of plasma. In addition, the activities of acetyl-CoA carboxylase (EC6.4.1.2; CBX), fatty acid synthetase (FAS), ATP citrate lyase (EC4.1.3.8; CCE) and malate dehydrogenase (decarboxylating) (NADP) (EC1.1.1.40; ME) were assayed in liver and in abdominal and neck adipose tissues (AAT and NAT, respectively).Body-weight and carcass lipids failed to return to normal in quail that had been starved for 48 h and refed during 24 h. When starving lasted 60 h, carcass lipids almost resumed the normal level only after 48 h of refeeding. All refeeding treatments caused a 2–3-fold increase in liver weight, with a parallel rise in fat content.In the livers of the refed quail the specific activities of all enzymes, except CBX, reached or slightly exceeded pre-starvation levels. Because of liver enlargement, the total activities of the lipogenic enzymes in the starved–refed quail exceeded pre-starvation levels. In the normally-fed quail the contribution of AAT and NAT to total lipogenesis was insignificant, and in the starved–refed birds it still remained very small compared to that of liver, despite the pronounced relative increase of lipogenic enzyme activities in these adipose tissues.

Effect of Glucose or Oil Supplementation on Lipogenic Enzymes in Overfed Chicks

Chicks of a light breed, aged 26 days, were force-fed by intubation for 10 days. The feed administered consisted of a basal low-fat closed formula cereal based diet and of supplements of either glucose or soybean oil supplied in isoenergetic amounts. Ad libitum-fed chicks served as controls. At the end of the experiment, the weights and lipid contents of carcass, livers and abdominal adipose tissue were determined, as was the glucose and lipid content of plasma. In addition the activities of citrate cleavage and malic enzymes were assayed in livers and adipose tissue. The increased weight and lipid content caused by glucose or oil supplements were similar in carcass and adipose tissue, but liver weight and fat content were increased much more by the glucose supplement than by the oil. The lipids which accumulated in the livers of force-fed chicks were essentially triglycA©rides. The glucose supplement caused a pronounced drop in the linoleic acid content of liver lipids, as well as an increase in oleic acid, whereas the oil produced the opposite effect. The glucose supplement caused a more pronounced hyperglycemia and hyperlipemia than did the oil. Activities of citrate cleavage and malic enzymes increased in proportion to the amount of carbohydrates force-fed in excess of the control intake. These and previous results show that chicks adapt to excess carbohydrate intake by both liver enlargement and increased activity of lipogenic en zymes. ' J. Nutr. JOS: 490-496, 1978.

Effects of progesterone and oestradiol on endometrial metabolism and embryo survival in the ovariectomized ewe

Our objective was to investigate the lipid content of uterus, blood plasma, and milk at early, mid, and late diestrus. Lactating cows (n = 30) had the estrous cycle and ovulation synchronized by administration of exogenous hormones. Cows were blocked by parity and assigned randomly to receive transcervical uterine flushing and biopsy on d 5 (early diestrus), 10 (mid diestrus) or 15 (late diestrus) of the estrous cycle. Flushing and endometrial biopsy were performed in the uterine horn ipsilateral to the corpus luteum. The recovered flushing was used for analyses of lipid composition by liquid chromatography-tandem mass spectrometry and the biopsy was used for investigation of lipid droplet abundance in endometrial cryosections using a neutral lipid fluorescent dye. In addition, blood and milk samples were collected from all cows on d 5, 10, and 15. All blood samples were used to measure the concentration of progesterone in plasma, and all milk samples were used to determine milk composition. Subsamples of blood plasma and milk were also used to evaluate the composition of fatty acids and oxylipins using the same methodology used for uterine flushing samples. The abundance of lipid droplets in the endometrium increased 1.9-fold from d 5 to 10, and 2-fold from d 10 to 15. Concentration of long-chain fatty acids and oxylipins in uterine flushing were, on average, 2.2 and 2.5 times greater in samples collected on d 15 compared with those collected on d 5 and 10. These differences were not observed in blood and milk, suggesting that accumulation of fatty acids and oxylipins in the uterus is regulated locally. In addition to concentration, the profile of individual fatty acids and oxylipins in uterine lumen changed substantially during diestrus. The main categories with increased abundance at late diestrus were mono- and polyunsaturated fatty acids, and oxylipins derived from arachidonic acid, dihomo-γ-linolenic acid, and docosahexaenoic acid. In conclusion, fatty acids and oxylipins accumulate in the uterine lumen during diestrus and might work as a mechanism to supply these lipids to the developing conceptus at late diestrus, when the onset of elongation occurs and substantial synthesis of biomass and cell signaling by lipid mediators are required.

Lipid Composition of Bovine Spermatozoa and Seminal Plasma

Summary Total lipid content of bovine spermatozoa and seminal plasma averaged 12.0 and 1.35%, respectively. Lipids separated by thin-layer chromatography and analyzed gravimetrically, averaged for spermatozoa (%): phospholipids 73.3, cholesterol 14.5, diglycerides 6.5, triglycerides 3.1, and wax esters 2.6. Similar values for seminal plasma were: phospholipids 68.6, cholesterol 20.2, diglycerides 4.0, triglycerides 4.0, and wax esters, 3.2.

Lipid content of chick erythrocytes and plasma.

SummaryData are presented on the composition of chick plasma and erythrocyte lipids. The erythrocyte lipids differ from plasma lipids in that 96% of the cholesterol is present as the free form, lipid phosphorus is over twice as high as the plasma level, and the glyceride level is approximately one-third that of plasma. The total lipid level of red cells (mg/100 ml) was also found to be higher than that of plasma. A lack of correlation between erythrocyte and plasma levels of cholesterol and glycerides was noted, indicating that erythrocyte lipid levels are independent of plasma concentration. The similarities between avian and mammalian erythrocyte lipids are discussed.