In vitro addition of epinephrine, norepinephrine, and carnitine alters palmitate oxidation and esterification in isolated ovine hepatocytes.

Hepatocytes from 4 wethers were used to study the effects of carnitine and increasing concentrations of epinephrine and norepinephrine on palmitate oxidation and esterification. Liver cells were isolated from the wethers and incubated in Krebs-Ringer bicarbonate buffer with 1 mM [14C]-palmitate. Radiolabel incorporation was measured in CO2, acid-soluble products, and esterified products, including triglyceride, diglyceride, and cholesterol esters. Carnitine increased production of CO2 and acid-soluble products from palmitate by 41% and 216%, respectively, but had no effect on conversion of palmitate to esterified products. Epinephrine had a quadratic-increasing effect on palmitate oxidation to CO2, but norepinephrine did not increase palmitate oxidation to CO2. Neither epinephrine nor norepinephrine affected the production of acid-soluble products from palmitate. Increasing concentrations of norepinephrine and epinephrine linearly increased rates of triglyceride formation from palmitate. Increasing norepinephrine concentrations linearly increased diglyceride and cholesterol ester formation from palmitate in the presence of carnitine; epinephrine did not affect diglyceride or cholesterol ester formation. In general, catecholamine treatment had the greatest effect on the formation of esterified products from palmitate, and effects of norepinephrine were more pronounced than epinephrine. Conditions that result in catecholamine release might lead to fat accumulation in the liver.

Effects of in vivo phlorizin treatment and in vitro addition of carnitine, propionate, acetate, and 5-tetradecyloxy-2-furoic acid on palmitate metabolism in ovine hepatocytes.

Modulatory effects of l-carnitine, acetate, propionate, and 5-tetradecyloxy-2-furoic acid (TOFA; an inhibitor of acetyl-CoA carboxylase) on oxidation and esterification of [1-14C]-palmitate were studied in hepatocytes isolated from phlorizin-treated and control wethers. Our hypotheses were that (1) palmitate oxidation would be greater in hepatocytes from sheep injected with phlorizin; (2) l-carnitine would increase palmitate oxidation more in hepatocytes from sheep injected with phlorizin; and (3) acetate and propionate would decrease oxidation in sheep hepatocytes partly through action of acetyl-CoA carboxylase. Palmitate metabolism did not differ between cells from control and those from phlorizin-treated wethers. Carnitine increased oxidation of palmitate to CO2 and acid-soluble products (ASP; mainly ketone bodies) and decreased esterification of palmitate in isolated hepatocytes from both groups of wethers, but the increase in oxidation to ASP was greater in cells from phlorizin-treated wethers. Propionate increased palmitate oxidation to CO2 in phlorizin-treated wethers. Propionate increased oxidation of palmitate to ASP in control wethers but decreased oxidation to ASP in phlorizin-treated wethers. Propionate increased esterification of palmitate to total esterified products and triglyceride, and the effect was larger in phlorizin-treated wethers. Acetate decreased palmitate esterification to total esterified products in control wethers, but the effect was blunted in phlorizin-treated wethers. Acetate did not affect palmitate oxidation. Addition of TOFA increased production of triglyceride from palmitate in the presence of propionate. The lack of interaction between TOFA and propionate indicates that propionate does not inhibit carnitine palmitoyltransferase I via cytosolic generation of methylmalonyl-CoA by acetyl-CoA carboxylase. In conclusion, although in vivo phlorizin treatment did not affect in vitro metabolism of palmitate by isolated ovine hepatocytes, phlorizin increased the stimulatory effect of carnitine on oxidation of palmitate to ASP and the inhibitory effect of propionate on oxidation of palmitate to ASP. Metabolism of acetate and propionate by acetyl-CoA carboxylase did not affect palmitate oxidation or esterification. Results provide additional insight into control of fatty acid metabolism in hepatocytes.

Increasing omega-3 levels through dietary co-extruded flaxseed supplementation negatively affects pork palatability.

To clarify the impact of feeding co-extruded flaxseed on carcass quality and pork palatability, 96 pigs (48 barrows and 48 gilts) were fed three different levels of flaxseed (0%, 5% and 10% of dietary intake) for 76days. Carcass quality and meat quality characteristics of pure loin muscle and ground pork (20% fat) were evaluated. Fat hardness and belly firmness decreased (P<0.001) with increasing co-extruded flaxseed. Pigs fed co-extruded flaxseed levels had higher lean yield (P=0.045) and total lean content (P=0.034). Loin from barrows had higher fat content compared to gilts (P<0.001). Co-extruded flaxseed supplementation increased (P<0.001) omega-3 content in loin and ground pork. Pork flavour intensity and off-flavour intensity scores lowered (P<0.001) with increasing levels of co-extruded flaxseed, being more accentuated (P=0.023) in reheated pork chops from barrows. Diet affected all texture and flavour sensory characteristics (P<0.05) as tissue levels of omega-3 fatty acids increased, likely as a result of increased lipid oxidation.

Human neutrophils produce high levels of the interleukin 1 receptor antagonist in response to granulocyte/macrophage colony-stimulating factor and tumor necrosis factor alpha.

Neutrophils, an abundant cell type at sites of inflammation, have the ability to produce a number of cytokines, including interleukin 1 (IL-1), IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor alpha (TNF-alpha). In this study, we have examined the ability of human neutrophils to produce the IL-1 receptor antagonist (IL-1Ra), a 17-23-kD protein recently isolated and cloned from macrophages. Since IL-1Ra has been shown to inhibit both the in vitro and in vivo effects of IL-1, its production by large numbers of tissue-invading neutrophils might provide a mechanism by which the effects of IL-1 are regulated in inflammation. Using antibodies that are specific for IL-1Ra and a cDNA probe encoding for this protein, we were able to show that neutrophils constitutively produce IL-1Ra. However, after activation by GM-CSF and TNF-alpha, IL-1Ra was secreted into the extracellular milieu where it constituted the major de novo synthesized product of activated neutrophils. None of a large array of other potent neutrophil agonists were found to affect the production of IL-1Ra by neutrophils. Quantitative measurements by enzyme-linked immunosorbent assay revealed that intracellular IL-1Ra is in eightfold excess of the amount secreted in supernatants when studying nonactivated neutrophils. However, in GM-CSF- and TNF-alpha-activated cells, this difference was reduced to values between four- and fivefold, as virtually all of the de novo synthesized IL-1Ra was secreted. In activated cells, the intracellular content of IL-1Ra was found to be in the 2-2.5-ng/ml range per 10(6) neutrophils, whereas levels reached the 0.5-ng/ml range in supernatants. This would imply that IL-1Ra is produced in excess of IL-1 by a factor of at least 100, an observation that is in agreement with the reported amounts of IL-1Ra needed to inhibit the proinflammatory effects of IL-1. Neutrophils isolated from an inflammatory milieu, the synovial fluid of patients with rheumatoid arthritis, were found to respond to GM-CSF and TNF-alpha in terms of IL-1Ra synthesis, indicating that the in vitro observations made in this study are likely to occur in an inflammatory setting in vivo.

Protective effects of licofelone, a 5-lipoxygenase and cyclo-oxygenase inhibitor, versus naproxen on cartilage loss in knee osteoarthritis: a first multicentre clinical trial using quantitative MRI.

OBJECTIVE: In a multicentre study to explore the effects of licofelone as a disease-modifying osteoarthritis drug in comparison with naproxen in patients with knee osteoarthritis (OA), using MRI and x-ray examination. METHODS: Patients with knee OA (n = 355) were randomised to receive either licofelone (200 mg twice a day) or naproxen (500 mg twice a day). MRI and x-ray examinations were performed at baseline, 6 months (MRI only), 12 and 24 months. MRI was used to assess quantitatively changes in cartilage volume, and x-ray examinations (Lyon-Schuss) to measure changes in the mean and minimum joint space width (JSW) in the medial compartment. Questionnaires probing symptoms were completed. Data were presented as intention to treat (ITT) and according to protocol (ATP). RESULTS: Cartilage volume loss in the global joint and medial and lateral compartments was significantly less in the licofelone than in the naproxen group for ITT at 12 and 24 months and for ATP at all times except in the medial compartment. Patients with medial meniscal extrusion had a greater loss of cartilage volume. In these patients, licofelone markedly reduced the cartilage loss for both ITT and ATP at 12 and 24 months. Although licofelone showed less reduction in the JSW than naproxen, this did not reach significance. All clinical variables were improved at 24 months (p<0.001) for both groups, with a good safety profile. CONCLUSION: Licofelone and naproxen were equally effective in reducing OA symptoms; however, licofelone significantly reduced cartilage volume loss over time, thus having a protective effect in patients with knee OA. This study proves the superiority of quantitative MRI over x-ray examinations in a multicentre clinical trial.

Once-daily, controlled-release tramadol and sustained-release diclofenac relieve chronic pain due to osteoarthritis: a randomized controlled trial.

OBJECTIVE: The present study was a randomized, parallel, double-blind comparison between controlled-release (CR) tramadol and sustained-release (SR) diclofenac in patients with chronic pain due to osteoarthritis of the hips and/or knees. METHODS: Patients with at least moderate pain intensity, and having received analgesics over the past three months, underwent a two- to seven-day washout of current analgesics before initiation of 200 mg CR tramadol or 75 mg SR diclofenac. During the eight-week study, patients returned to the clinic biweekly. CR tramadol doses were titrated to a maximum of 200 mg, 300 mg or 400 mg per day. SR diclofenac doses were titrated to 75 mg or 100 mg once daily, or 75 mg twice a day based on pain relief and the presence of side effects. For rescue analgesic, patients took acetaminophen as needed, up to 650 mg three times a day. RESULTS: Forty-five patients on CR tramadol and 52 patients on SR diclofenac were evaluable. Significant improvements from prestudy treatment were shown for visual analogue scale pain (P=0.0001), stiffness (P<0.0005) and physical function (P=0.0001) scores for both treatments. There were no significant differences between the two treatments in the Western Ontario and McMaster Universities subscales, overall pain, pain and sleep, or the clinical effectiveness evaluation. Overall incidence of adverse events was similar in both groups, with more opioid-related adverse events with CR tramadol, and two serious adverse events occurring with the use of SR diclofenac. CONCLUSIONS: CR tramadol is as effective as SR diclofenac in the treatment of pain due to knee or hip osteoarthritis, with the potential for fewer of the serious side effects that characterize nonsteroidal anti-inflammatory drug administration.

A randomized, double-blind, crossover comparison of the efficacy and safety of oral controlled-release tramadol and placebo in patients with painful osteoarthritis.

OBJECTIVE: To compare the efficacy and safety of controlled-release (CR) tramadol (Zytram XL, Purdue Pharma, Canada) and placebo in patients with painful osteoarthritis. METHODS: Patients underwent analgesic washout for two to seven days before random assignment to 150 mg daily of CR tramadol or placebo, and were titrated weekly to 200 mg, 300 mg or a maximum of 400 mg once daily. After four weeks, patients crossed over to the alternate treatment for another four weeks. Plain acetaminophen was provided as a rescue analgesic. All patients who completed the crossover study were eligible to receive open label CR tramadol for six months. RESULTS: Seventy-seven of 100 randomly assigned patients were evaluable for efficacy. CR tramadol resulted in significantly lower visual analogue scale pain intensity scores (37.4+/-23.9 versus 45.1+/-24.3, P=0.0009). Western Ontario and McMaster Universities osteoarthritis index subscale scores for pain (189.0+/-105.0 versus 230.0+/-115.4; P=0.0001) and physical function (632.4+/-361.3 versus 727.4+/-383.4; P=0.0205) were significantly better with CR tramadol. Total pain and disability (22.8+/-14.5 versus 27.2+/-14.8; P=0.0004), and overall pain and sleep (104.7+/-98.0 versus 141.0+/-108.2; P=0.0005) scores in the Pain and Sleep Questionnaire were significantly lower for CR tramadol. Short-form 36 Health Survey scores were significantly better during CR tramadol treatment for the pain index (38.8+/-10.8 versus 35.6+/-9.0; P=0.0100), general health perception (46.5+/-11.2 versus 44.4+/-11.6; P=0.0262), vitality (43.1+/-13.2 versus 40.2+/-13.7; P=0.0255) and overall physical components (40.8+/-8.9 versus 37.8+/-7.7; P=0.0002). CR tramadol treatment was preferred by 55.8% of patients (P=0.0005) versus 20.8% and 23.4% of patients who chose placebo or had no preference, respectively. These improvements were sustained for up to six months, and 86.5% of patients reported at least moderate benefit from CR tramadol during long-term treatment. CONCLUSION: CR tramadol is effective for the management of painful osteoarthritis.

Factors affecting the concentration of sphingomyelin in bovine milk.

Sphingomyelin is a phospholipid located in the outer leaflet of the plasma membrane of most cells and is a component of the milk fat globule membrane. Sphingomyelin and its digestion products participate in several antiproliferative pathways that may suppress oncogenesis. Although milk and dairy products are important sources of sphingomyelin in the human diet, little is known about factors that influence sphingomyelin concentrations in milk fat or whether concentrations can be modified via the nutrition of cows. Sphingomyelin concentrations were determined in milk from Holstein and Jersey cows matched for parity and stage of lactation. Sphingomyelin was more concentrated in milk fat from Holstein cows than in milk fat from Jersey cows (1,044 vs. 839 microg/g of fat). Concentrations in whole milk did not differ because of greater milk fat content for milk from Jerseys. Differences between breeds may be related to the greater fat globule size in milk from Jerseys. Sphingomyelin content in whole milk increased with increasing days in milk because of associated increases in milk fat content. Regardless of breed, primiparous cows had greater amounts of stearic acid and less palmitic acid in sphingomyelin than did older cows. The sphingomyelin concentration in milk fat of cows in a commercial Jersey herd was lower for cows in their fourth or greater parity. Sphingomyelin content in whole milk was greater for cows in late lactation because of greater milk fat content. Feed restriction of multiparous Holstein cows to 37% of ad libitum dry matter intake increased milk fat content but did not affect milk sphingomyelin content or milk fat globule size. Supplementation of the diet with 4% soybean oil did not affect milk composition, sphingomyelin content, or milk fat globule size. Milk was sampled seasonally from 7 herds throughout Illinois during a 2-yr period. Sphingomyelin concentration in milk fat was greatest during summer and least during winter, but whole milk concentrations did not vary across seasons. We conclude that 1) sphingomyelin content of milk fat is greater in milk from Holsteins than that from Jerseys, 2) sphingomyelin content in whole milk increases with stage of lactation, and 3) sphingomyelin content of milk fat is greater during summer. However, efforts to produce milk with a greater sphingomyelin content through altering management and nutrition are unlikely to be successful.

Prepartum nutrition alters fatty acid composition in plasma, adipose tissue, and liver lipids of periparturient dairy cows.

The fatty acyl profile of phospholipids (PL) determines the fluidity of cell membranes and affects cell function. The degree to which long-chain fatty acid (LCFA) composition of PL and triacylglycerols (TG) in liver and total lipids in adipose tissue can be altered by prepartum nutrition in peripartal dairy cows is unclear. Multiparous Holsteins (n = 25) were assigned to 1 of 4 prepartal diets: 1) CA, the control diet fed to meet 120% of energy requirements; 2) CR, a control diet fed to meet 80% of requirements; 3) S, a diet supplemented with mostly saturated free fatty acids (47% 16:0, 36% 18:0, 14% cis-18:1) and fed to meet 120% of requirements; or 4) U, a diet similar to S except that cows were abomasally infused with soybean oil so that the diet plus infused fat would meet 120% of requirements. Diets were fed for 40 d prepartum; all cows received a lactation diet postpartum. Groups CR and U had lower prepartum intakes of dry matter and net energy, but glucose concentrations in plasma were similar among treatments. Cows fed S, U, or CR had greater nonesterified fatty acids in plasma prepartum, but cows fed U had decreased beta-hydroxybutyrate postpartum. Postpartal concentrations of total lipids and glycogen in liver tissue were similar among treatments. Cows in group U had a greater percentage of 18:2 but less 16:0, 18:0, and 20:4 in plasma total lipids than cows fed S. Treatment U increased 18:2 and 18:3 and decreased 18:1 in subcutaneous adipose tissue at 1 d postpartum. Across diets, percentages of 16:0 and trans-18:1 were increased, and 18:0, 20:3, and 20:5 were decreased, in hepatic PL at d 1 postpartum. Significant treatment x time interactions indicated that treatment U increased 18:2 in hepatic PL at the expense of 18:1, 20:3, 20:4, 22:6, and 24:0 on d 1 postpartum, but changes were normalized by d 65 postpartum. The unsaturation index of hepatic PL was lower at d 1 than at d -45 or 65, which implies that hepatic membrane fluidity decreased around parturition. The unsaturation index at d 1 was greater for cows fed S than those fed CA or U. Percentages of 16:0, 18:1, and 22:0 were increased, and 18:0, 20:3, 20:4, 20:5, 24:0, and 26:0 were decreased, in hepatic TG at d 1. Prepartal feed restriction modestly affected tissue LCFA profiles. The LCFA profile of adipose tissue, liver PL, and liver TG can be altered by dietary LCFA supply prepartum; changes in liver are normalized by 65 d postpartum.

Responses to increasing amounts of high-oleic sunflower fatty acids infused into the abomasum of lactating dairy cows.

Increasing the oleic acid (18:1 cis-9) content of milk fat might be desirable to meet consumer concerns about dietary healthfulness and for certain manufacturing applications. The extent to which milk fat could be enriched with oleic acid is not known. Increasing the intestinal supply of polyunsaturated fatty acids decreases dry matter intake (DMI) in cows, but the effects of oleic acid have not been quantified. In a crossover design, 4 multiparous Holstein cows were abomasally infused with increasing amounts (0, 250, 500, 750, or 1,000 g/d) of free fatty acids from high-oleic sunflower oil (HOSFA) or with carrier alone. Continuous infusions (20 to 22 h/d) were for 7 d at each amount. Infusions were homogenates of HOSFA with 240 g/d of meat solubles and 11.2 g/d of Tween 80; controls received carrier only. The HOSFA contained (by wt) 2.4% 16:0, 1.8% 18:0, 91.4% 18:1 cis-9, and 2.4% 18:2. The DMI decreased linearly (range 22.0 to 5.8 kg/d) as the infused amount of HOSFA increased. Apparent total tract digestibilities of dry matter, organic matter, neutral detergent fiber, and energy decreased as the infusion increased to 750 g/d and then increased when 1,000 g/d was infused. Digestibility of total fatty acids increased linearly as infused fatty acids increased. Yields of milk, fat, true protein, casein, and total solids decreased quadratically as infused amounts increased; decreases were greatest when 750 or 1,000 g/d of HOSFA were infused. Concentrations of fat and total solids increased at the higher amounts of HOSFA. The volume mean diameter of milk fat droplets and the diameter below which 90% of the volume of milk fat is contained both increased as HOSFA infusion increased. Concentrations of short-chain fatty acids, 12:0, 14:0, and 16:0 in milk fat decreased linearly as HOSFA increased. The concentration of 18:1 cis-9 (19.4 to 57.4% of total fatty acids) increased linearly as HOSFA infusion increased. Concentrations of 18:1 cis-9 in blood triglyceride-rich lipoproteins increased linearly as infusion increased, whereas contents of 14:0, 16:0, 18:0, total 18:1 trans, and 18:2n-6 decreased linearly. The composition and physical characteristics of milk fat can be altered markedly by an increased intestinal supply of 18:1 cis-9, which could influence processing characteristics and the healthfulness of milk fat. However, an increased supply of free 18:1 cis-9 to the intestine decreased DMI and milk production.

Effects of dietary calcium and phosphorus on reproductive performance and markers of bone turnover in stall- or group-housed sows.

Increasing productivity and new housing standards necessitate a reevaluation of nutrient requirements for sows, including minerals. The objective of this study was to determine if the recommended levels of dietary Ca and P are adequate for sows housed in groups and that, therefore, have the potential for increased mobility. A total of 180 multiparous sows and gilts were assigned to 1 of 6 treatments. Treatments, arranged as a 3 × 2 factorial, included the main effects of dietary Ca:P-0.70:0.55% Ca:P (as-fed basis; control), 0.60:0.47% Ca:P (as-fed basis; Low CaP), and 0.81:0.63% Ca:P (as-fed basis; High CaP)-and housing-stalls or groups. The trial was initiated when sows were moved from the breeding stalls to the gestation room at wk 4 or 5 after breeding. Sows were initially fed 2.3 kg/d. This allotment was increased to 3.0 kg/d 2 wk prior to farrowing. Group-housed sows, fed in individual stalls, were allowed access to a loafing area after feeding. Serum samples were collected at the start of the trial and on d 100 of gestation, and both serum and milk samples were collected at mid lactation and prior to weaning. Neither diet nor housing had an effect on the total number of piglets born, ADG from birth to weaning, or weaning weight ( > 0.10). The number of live-born piglets and birth weight were unaffected by diet ( > 0.10) but were improved by group housing relative to stalls ( < 0.05). In late gestation, group-housed sows fed the Low CaP diet had reduced serum Ca (diet × housing interaction, = 0.02), and the greatest reduction (between d 28 and 100 of gestation) in serum P level was observed in group-housed sows fed the Low CaP diet (diet × housing interaction, = 0.04). Osteocalcin and pyridinoline, markers of bone formation and resorption, respectively, were unaffected by diet or housing ( > 0.10). Results from these studies imply that the level of dietary Ca and P recommended by the NRC is adequate for sows of modern genetics, whether housed in stalls or groups.

Granulocyte-macrophage colony-stimulating factor modulates tapasin expression in human neutrophils.

Differential display-polymerase chain reaction (DD-PCR) was used to evaluate changes in mRNA expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) treated human neutrophils to better understand how this cytokine affects the functions of neutrophils at the molecular level. Although a variety of cDNA fragments were identified as modulated by GM-CSF with the use of DD-PCR, one fragment in particular, NGS-17 (neutrophil GM-CSF-stimulated fragment #17), was characterized. The NGS-17 fragment hybridized to a 3.8-kh mRNA that encodes for a protein of a predicted molecular mass of 47.6 kDa. After cloning and sequencing, this gene was found to code for the recently sequenced tapasin or TAP-A protein. Immunoprecipitation and immunoblotting studies using anti-tapasin antibodies showed that tapasin is expressed in neutrophils and is associated with the MHC class I-TAP complex. Moreover, tapasin expression was found to be induced by dimethyl sulfoxide and by retinoic acid in HL-60 cells. This is the first report on the expression of tapasin in human neutrophils. It provides novel information, at the molecular level, on how GM-CSF enhances the functions of these cells.

Effects of interleukin-13 on human neutrophil functions.

It was recently shown that interleukin-13 (IL-13) induces the expression and release of the IL-1 decoy receptor (type II) in human neutrophils along with the production of the IL-1 receptor antagonist. In the present study we focused on further studying the modulatory effects of IL-13 on these cells. We found that recombinant human IL-13 (rhIL-13) induces cellular morphological changes in neutrophils that are typical of activated cells. Furthermore, rhIL-13 was shown to increase tyrosine phosphorylation of several neutrophil proteins. We also demonstrate that this cytokine stimulates de novo RNA synthesis in a concentration-dependent fashion as measured by [5-3H]uridine incorporation and that rhIL-13 induces the synthesis of several neutrophil proteins according to high-resolution two-dimensional gel electrophoresis of metabolically [35S]-labeled cells. We observed that the IL-8 levels in the external milieu of IL-13-stimulated cells was almost fivefold increased when compared with control cells. Finally, we observed that rhIL-13 has no significant effect on phagocytosis and apoptosis. Taken together, our results demonstrate that IL-13 is a modulator of several human neutrophil functions. This leads us to conclude that the modulatory role of IL-13 on human neutrophils, a potentially important anti-inflammatory cytokine, is more complex than previously believed. Furthermore, because we show that the synthesis of several as yet unidentified proteins was up-regulated by IL-13, our findings open new avenues of research on the effects of this cytokine on human neutrophils.

Carboxypeptidase N (kininase I) activity in blood and synovial fluid from patients with arthritis.

Carboxypeptidase N (CPN, kininase I) and kininase II (angiotensin converting enzyme) activities were measured simultaneously in blood plasma and synovial fluid in patients suffering from rheumatoid arthritis (RA), psoriatic arthritis (PA) and osteoarthritis (OA) and in the plasma of normal volunteers. CPN levels (defined as the rate of hydrolysis of furylacryloyl-Ala-Lys) in blood were modestly increased and correlated with erythrocyte sedimentation rate in RA and PA. Based on the hydrolysis of synthetic substrates, CPN activity was much higher than kininase II activity in synovial fluid (SF). SF kininase activities were always inferior to the blood levels in all patients and were correlated with the logarithm of SF leukocyte counts, an indicator of the intensity of inflammation. In addition, CPN and albumin levels in SF were highly correlated when expressed as a percent of the plasma concentrations. Biochemical properties of CPN in crude SF confirmed its similarity to blood CPN. Polymorphonuclear leukocytes derived from inflammatory SF did not release CPN. It is concluded that kininases diffuse from the blood into SF through increased vascular permeability and that CPN could be a major metabolic pathway for kinins in this form of exudate. CPN leads to the formation of des-Arg kinins, selective agonists of the B1 receptors for kinins.

Concentrations of conjugated linoleic acid (cis-9, trans-11-octadecadienoic acid) are not increased in tissue lipids of cattle fed a high-concentrate diet supplemented with soybean oil.

Conjugated linoleic acid (CLA), a mixture of isomers of linoleic acid, has many beneficial effects, including decreased tumor growth in animal cancer models. The cis-9, trans-11 isomer of CLA (CLA9,11) can be formed in the rumen as an intermediate in biohydrogenation of linoleic acid. Recent data, however, indicate that tissue desaturation of trans-fatty acids is an important source of CLA9,11 in milk. Our objective was to determine whether supplementing a high-corn diet with soybean oil (SBO; a source of linoleic acid) would increase concentrations of CLA in ruminal contents and tissue lipids. Four ruminally cannulated steers were utilized in a Latin square design with 28-d periods. A control diet (80% cracked corn, 2.0% corn steep liquor, 8.0% ground corn cobs, and 10% supplement [soybean meal, ground shelled corn, minerals, and vitamins]) was supplemented with 2.5, 5.0, or 7.5% (DM basis) SBO. Supplemental SBO did not affect ruminal pH or concentrations of the major VFA. The proportion and amount (mg FA/g DM ruminal contents) of CLA9,11 were not increased by increasing dietary SBO. However, the proportion and amount of the trans-10, cis-12 CLA isomer (CLA10,12) in ruminal contents increased linearly (P < 0.006) as dietary SBO increased. Trans-18:1 isomers in ruminal contents increased linearly (P < 0.02) as dietary SBO increased. The proportion of CLA10,12 was correlated positively (P < 0.001) with proportions of trans-C 18:1 isomers in ruminal contents. Conversely, CLA9,11 was correlated negatively (P < 0.05) with the proportions of trans-18:1 in ruminal contents. The same high-corn diet, supplemented with 0 or 5% SBO, was fed to 20 Angus-Wagyu heifers for 102 d in a randomized complete block design to determine the effect of added SBO on tissue deposition of CLA. Supplemental SBO did not affect feed intake, gain:feed, or carcass quality. Tissue samples were obtained from the hindquarter, loin, forequarter, liver, large and small intestine, and subcutaneous, mesenteric, and perirenal adipose depots. The concentration of CLA9,11 was greatest in subcutaneous adipose tissue but was not affected in any tissue by SBO. Supplementing high-corn diets with SBO does not increase CLA9,11 concentrations in tissues of fattening heifers. Research is needed to identify regulatory factors for pathways of biohydrogenation that lead to increased concentrations of CLA10,12 in ruminal contents when high-oil, high-concentrate diets are fed.

Effects of saturation and esterification of fat sources on site and extent of digestion in steers: digestion of fatty acids, triglycerides, and energy.

Five steers (mean BW 526 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 5 x 6 Youden square design with 14-d periods. Diets contained chopped alfalfa hay, corn silage, and concentrate (25:35:40, DM basis). Treatments were 1) control (no added fat); 2) tallow (T), iodine value (IV) = 51.5; 3) partially hydrogenated tallow (PHT), IV = 30.7; 4) hydrogenated tallow (HT), IV = 6.9; 5) blend (1: 1) of HT and hydrogenated free fatty acids (HTHFA), IV = 9.0; and 6) hydrogenated free fatty acids (HFA), IV = 11.2. Fats replaced cornstarch in the control diet to supply 5% added fatty acids. Intake was restricted to 90% of ad libitum; DMI was similar among diets (mean 9 kg/d). Total fatty acid intake averaged 170, 500, 506, 525, 489, and 491 g/d for treatments 1 to 6, respectively. Flows of total C16, total C18, and total fatty acids to the duodenum were increased by supplemental fat; flows of total C18 and total fatty acids were greater than their intake for all treatments. Flow of total fatty acids associated with ruminal bacteria accounted for 50 and 17% of the total duodenal fatty acid flow for the control and fat-supplemented diets, respectively. Digestibility of total fatty acids entering the small intestine (74, 71, 62, 39, 53, and 63% for treatments 1 to 6, respectively) was greater for the control diet than for fat-supplemented diets and decreased as either saturation (T < PHT < HT) or esterification (HFA < HTHFA < HT) increased. Digestibilities of fatty acids in the total tract followed similar patterns. Ruminal lipolysis of dietary triglycerides decreased linearly as the degree of saturation of fat sources increased. Small intestinal disappearance of triglycerides (89, 75, 51, 44, 64, and 73% of duodenal flow for treatments 1 to 6, respectively) decreased linearly as either saturation or esterification increased. Flows and digestion of gross energy followed patterns similar to those for fatty acids and triglycerides. Resistance to ruminal and small intestinal lipolysis is a major factor contributing to the poor digestibility of highly saturated triglycerides.

Metabolic adaptation to experimentally increased glucose demand in ruminants.

Four Dorset wethers were studied in a Latin square design with 72-h periods to determine the metabolic adaptations that occur in support of increased glucose demand in ruminants. Wethers injected at 8-h intervals with excipient or a total of .5, 1.0, or 2.0 g/d of phlorizin excreted an average of 0, 72.7, 97.9, and 98.5 g/d of glucose into the urine, respectively. Both acute (2 to 24 h after the first injection) and chronic (8-h intervals from 8 to 72 h after the first injection) adaptations of plasma variables to phlorizin treatment were assessed. Concentrations of plasma glucose decreased linearly with increasing phlorizin dose during the 1st 24 h of treatment and tended to decrease linearly with phlorizin dose during 8 to 72 h of treatment. Urea N tended to increase linearly during 2 to 24 h and increased linearly during 8 to 72 h. Nonesterified fatty acids increased linearly with phlorizin injection during the entire treatment period. beta-Hydroxybutyrate increased quadratically with phlorizin injection during 2 to 24 h and tended to increase quadratically during 8 to 72 h. The ratio of insulin to glucagon tended to decrease linearly with phlorizin injection during the 1st 24 h but was unaffected from 8 to 72 h. Triiodothyronine, but not thyroxine, tended to decrease linearly with phlorizin injection during 8 to 72 h. Cortisol was not affected by treatment. Digestibilities of energy and N were not affected by treatment. Urinary energy excretion increased with phlorizin injection in proportion to the amounts of glucose excreted into the urine. These data indicate that phlorizin-treated wethers largely adapted to phlorizin treatment by 24 h after the first injection and are a suitable model for further investigations of hepatic adaptation to increased glucose demand in ruminants.

Isolated canine and murine intestinal cells exhibit a different pattern of fuel utilization for oxidative metabolism.

The amount and type of dietary fiber influences the end-products of fermentation and thus fuel availability to intestinal tissue. Metabolic fuel usage was studied in intestinal cells isolated from dogs consuming a commercial diet or from rats consuming either a commercial rat diet or dog diet to examine preferential fuel usage, the effect of diet, and species differences. Production of 14CO2 was measured by incubating cells in media containing either D-[U-14C]glucose, [1-14C]n-butyrate, L-[U-14C]glutamine, or [1-14C]propionate with or without competing substrates. The presence of a mixture of 5 mM each of glucose, butyrate, propionate, and acetate and 1 mM glutamine in the media decreased CO2 production from glucose, glutamine, and propionate by canine enterocytes (P < 0.05) and from glutamine and propionate by canine colonocytes (P < 0.05). The presence of glutamine in the media decreased glucose oxidation by murine enterocytes, regardless of the diet. Similarly, glutamine decreased glucose oxidation by murine colonocytes (P < 0.05), but only when the rats had consumed the rat diet. Regardless of diet, murine colonocytes oxidized more butyrate (P < 0.01) than did enterocytes, and murine enterocytes tended (P < 0.07) to oxidize more glucose than did colonocytes. The proportion of propionate in colonic contents was higher in dogs than in rats (P < 0.02), and the proportion of butyrate tended to be higher in contents from rats than in those from dogs (P < 0.08). Colonic and cecal wet weights were decreased (P < 0.05) when rats were fed the commercial dog diet. Preferred utilization of substrates by isolated canine enterocytes and colonocytes differed from that of murine intestinal cells. These differences were only partially overcome by feeding the same diet to each species.

Substrate utilization for hepatic gluconeogenesis is altered by increased glucose demand in ruminants.

Hepatocytes isolated from 10 Dorset wethers that were treated with excipient or 1.0 g/d of phlorizin for 72 h were used to determine the effects of increased glucose demand on utilization of [1-(14)C]propionate and [1-(14)C] alanine for oxidative metabolism and gluconeogenesis. Control and phlorizin-treated wethers excreted 0 and 62.8 g/d of glucose into the urine, respectively. Phlorizin treatment tended to increase conversion of propionate and alanine to CO2. A phlorizin x substrate interaction for conversion to glucose indicated that conversion of alanine to glucose was increased more by phlorizin treatment than was conversion of propionate (285 vs 166% of controls). Phlorizin treatment did not affect estimated Ks for conversion of substrates to either CO2 or glucose; however, phlorizin increased estimated Vmax for conversion of substrates to CO2 and tended to increase estimated Vmax for conversion of substrates to glucose. Phlorizin treatment slightly increased the ratio of conversion of propionate to glucose compared with CO2 and slightly decreased the ratio of conversion of alanine to glucose compared with CO2. In vitro addition of 2.5 mM NH4Cl decreased conversion of propionate to CO2 and glucose but had little effect on conversion of alanine to CO2 and glucose. Estimated Ks and Vmax for conversion of substrates to CO2, Ks for conversion of substrates to glucose, and Vmax for conversion of alanine to glucose were not affected by NH4Cl; however, Vmax for conversion of propionate to glucose was decreased by NH4Cl. These data indicate that although utilization of propionate for gluconeogenesis is extensive, amino acids have the potential to increase in importance as gluconeogenic substrates when glucose demand is increased substantially. Furthermore, excess ammonia decreases the capacity of hepatocytes to utilize propionate for oxidation and gluconeogenesis.

Changing the omega-6 to omega-3 fatty acid ratio in sow diets alters serum, colostrum, and milk fatty acid profiles, but has minimal impact on reproductive performance.

This experiment tested the hypothesis that reducing the omega-6 (n-6) to omega-3 (n-3) fatty acid (FA) ratio in sow diets will improve performance, characterized by increased litter size, decreased preweaning mortality, and improved growth performance. Second, we determined if the FA profile in sow and piglet blood, colostrum, and milk are altered when sows are fed diets with varied n-6:n-3 ratios and if the dietary FA ratio impacts circulating concentrations of IgG, IgA, eicosapentaenoic (EPA), or docosahexaenoic (DHA) acid. Sows (n=150) were assigned to 1 of 5 treatments (each divided into gestation and lactation diets) on d 80 of gestation. Period 1 (P1) is defined as d 80 of gestation to weaning and Period 2 (P2) refers to the subsequent breeding to weaning. Diets were wheat and barley based (5% crude fat) and treatments consisted of a control (tallow), 3 diets with plant oil-based n-6:n-3 ratios (9:1P, 5:1P, and 1:1P), and a 5:1 fish oil diet (5:1F). Litter size was unaffected by treatment during P1 and P2 (P>0.10). In P1, birth weight was unaffected by diet (P>0.10); however, weaning weight (P=0.019) and ADG from birth to weaning (P=0.011) were greatest for piglets born to 9:1P and 5:1P sows. During P2, 5:1F sows consumed 10% less feed during lactation (P=0.036), tended to have reduced piglet birth weights (P=0.052), and piglet weaning weight was reduced by 0.8 kg (P=0.040) relative to the other diets. Colostrum and piglet serum IgA and IgG concentrations were unaffected by diet (P>0.10). Serum n-3 FA were greatest in sows (P<0.01) consuming 1:1P and 5:1F diets and in their offspring (P=0.014). Serum α-linolenic acid (ALA) was greatest in 1:1P sows and EPA and DHA were greatest in 5:1F sows (P<0.01). In pre-suckle piglet serum, ALA did not differ among treatment groups (P>0.10). Relative to piglets of sows consuming the control diet, EPA was 2.5-fold greater in the 1:1P group and 4-fold greater in 5:1F group (P<0.01) before suckling. In post-suckle samples, ALA was greatest in piglets from the 1:1P sows (P<0.01) and EPA and DHA were greatest in piglets from the 5:1F sows (P<0.01). Feeding diets with plant-based n-6:n-3 ratios of 5:1 or 1:1 did not impact performance relative to a control group but improved the conversion of ALA into EPA and increased the transfer of n-3 to piglets through milk. When a fish-based 5:1 ratio diet was fed, pre-weaning mortality was increased, and piglet birth and weaning weights decreased.