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Drake RR, Louey S, Thornburg KL. Maturation of lipid metabolism in the fetal and newborn sheep heart. Am J Physiol Regul Integr Comp Physiol 2023; 325:R809-R819. [PMID: 37867472 PMCID: PMC11178298 DOI: 10.1152/ajpregu.00122.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/26/2023] [Accepted: 09/29/2023] [Indexed: 10/24/2023]
Abstract
At birth, the fetus experiences a dramatic change in environment that is accompanied by a shift in myocardial fuel preference from lactate and glucose in fetal life to fatty acid oxidation after birth. We hypothesized that fatty acid metabolic machinery would mature during fetal life in preparation for this extreme metabolic transformation at birth. We quantified the pre- (94-day and 135-day gestation, term ∼147 days) and postnatal (5 ± 4 days postnatal) gene expression and protein levels for fatty acid transporters and enzymes in hearts from a precocial species, the sheep. Gene expression of fatty acid translocase (CD36), acyl-CoA synthetase long-chain 1 (ACSL1), carnitine palmitoyltransferase 1 (CPT1), hydroxy-acyl dehydrogenase (HADH), acetyl-CoA acetyltransferase (ACAT1), isocitrate dehydrogenase (IDH), and glycerol phosphate acyltransferase (GPAT) progressively increased through the perinatal period, whereas several genes [fatty acid transport protein 6 (FATP6), acyl-CoA synthetase long chain 3 (ACSL3), long-chain acyl-CoA dehydrogenase (LCAD), very long-chain acyl-CoA dehydrogenase (VLCAD), pyruvate dehydrogenase kinase (PDK4), phosphatidic acid phosphatase (PAP), and diacylglycerol acyltransferase (DGAT)] were stable in fetal hearts and had high expression after birth. Protein expression of CD36 and ACSL1 progressively increased throughout the perinatal period, whereas protein expression of carnitine palmitoyltransferase 1a (fetal isoform) (CPT1a) decreased and carnitine palmitoyltransferase 1b (adult isoform) (CPT1b) remained constitutively expressed. Using fluorescent-tagged long-chain fatty acids (BODIPY-C12), we demonstrated that fetal (125 ± 1 days gestation) cardiomyocytes produce 59% larger lipid droplets (P < 0.05) compared with newborn (8 ± 1 day) cardiomyocytes. These results provide novel insights into the perinatal maturation of cardiac fatty acid metabolism in a precocial species.NEW & NOTEWORTHY This study characterized the previously unknown expression patterns of genes that regulate the metabolism of free fatty acids in the perinatal sheep myocardium. This study shows that the prenatal myocardium prepares for the dramatic switch from carbohydrate metabolism to near complete reliance on free fatty acids postnatally. Fetal and neonatal cardiomyocytes also demonstrate differing lipid storage mechanisms where fetal cardiomyocytes form larger lipid droplets compared with newborn cardiomyocytes.
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Affiliation(s)
- Rachel R Drake
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon, United States
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
| | - Samantha Louey
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Kent L Thornburg
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon, United States
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States
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Uken KL, Schäff CT, Vogel L, Gnott M, Dannenberger D, Görs S, Tuchscherer A, Tröscher A, Liermann W, Hammon HM. Modulation of colostrum composition and fatty acid status in neonatal calves by maternal supplementation with essential fatty acids and conjugated linoleic acid starting in late lactation. J Dairy Sci 2021; 104:4950-4969. [PMID: 33589265 DOI: 10.3168/jds.2020-19627] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/11/2020] [Indexed: 01/11/2023]
Abstract
Sufficient maternal supply of essential fatty acids (EFA) to neonatal calves is critical for calf development. In the modern dairy cow, EFA supply has shifted from α-linolenic acid (ALA) to linoleic acid (LA) due to the replacement of pasture feeding by corn silage-based diets. As a consequence of reduced pasture feeding, conjugated linoleic acid (CLA) provision by rumen biohydrogenation was also reduced. The present study investigated the fatty acid (FA) status and performance of neonatal calves descended from dams receiving corn silage-based diets and random supplementation of either 76 g/d coconut oil (CTRL; n = 9), 78 g/d linseed oil and 4 g/d safflower oil (EFA; n-6/n-3 FA ratio = 1:3; n = 9), 38 g/d Lutalin (BASF SE, Ludwigshafen, Germany) providing 27% cis-9,trans-11 and trans-10,cis-12 CLA, respectively (CLA; n = 9), or a combination of EFA and CLA (EFA+CLA; n = 11) in the last 9 wk before parturition and following lactation. The experimental period comprised the first 5 d of life, during which calves received colostrum and transition milk from their own dam. The nutrient compositions of colostrum and transition milk were analyzed. Plasma samples were taken after birth and before first colostrum intake and on d 5 of life for FA analyses of the total plasma fat and lipid fractions. Maternal EFA and CLA supplementation partly affected colostrum and transition milk composition but did not change the body weights of calves. Most EFA in calves were found in the phospholipid (PL) and cholesterol ester (CE) fractions of the plasma fat. Maternal EFA supplementation increased the percentage of ALA in all lipid fractions of EFA and EFA+CLA compared with CTRL and CLA calves on d 1 and 5, and the increase was much greater on d 5 than on d 1. The LA concentration increased from d 1 to 5 in the plasma fat and lipid fractions of all groups. The concentrations of docosapentaenoic acid, docosahexaenoic acid, and arachidonic acid in plasma fat were higher on d 1 than on d 5, and the percentage of n-3 metabolites was mainly increased in PL if dams received EFA. The percentage of cis-9,trans-11 CLA was higher in the plasma fat of EFA+CLA than CTRL calves after birth. By d 5, the percentages of both CLA isomers increased, leading to higher proportions in plasma fat of CLA and EFA+CLA than in CTRL and EFA calves. Elevated cis-9,trans-11 CLA enrichment was observed on d 5 in PL, CE, and triglycerides of CLA-treated calves, whereas trans-10,cis-12 CLA could not be detected in individual plasma fractions. These results suggest that an altered maternal EFA and CLA supply can reach the calf via the placenta and particularly via the intake of colostrum and transition milk, whereas the n-3 and n-6 FA metabolites partly indicated a greater transfer via the placenta. Furthermore, the nutrient supply via colostrum and transition milk might be partly modulated by an altered maternal EFA and CLA supply but without consequences on calf performance during the first 5 d of life.
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Affiliation(s)
- K L Uken
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - C T Schäff
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - L Vogel
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - M Gnott
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - D Dannenberger
- Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - S Görs
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - A Tuchscherer
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | | | - W Liermann
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - H M Hammon
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
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Gnott M, Vogel L, Kröger-Koch C, Dannenberger D, Tuchscherer A, Tröscher A, Trevisi E, Stefaniak T, Bajzert J, Starke A, Mielenz M, Bachmann L, Hammon HM. Changes in fatty acids in plasma and association with the inflammatory response in dairy cows abomasally infused with essential fatty acids and conjugated linoleic acid during late and early lactation. J Dairy Sci 2020; 103:11889-11910. [PMID: 32981719 DOI: 10.3168/jds.2020-18735] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022]
Abstract
Dairy cows are exposed to increased inflammatory processes in the transition period from late pregnancy to early lactation. Essential fatty acids (EFA) and conjugated linoleic acid (CLA) are thought to modulate the inflammatory response in dairy cows. The present study investigated the effects of a combined EFA and CLA infusion on the fatty acid (FA) status in plasma lipids, and whether changes in the FA pattern were associated with the acute phase and inflammatory response during late pregnancy and early lactation. Rumen-cannulated Holstein cows (n = 40) were assigned from wk 9 antepartum to wk 9 postpartum to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 g/d of linseed oil and 4 g/d of safflower oil; ratio of oils = 19.5:1; n-6:n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; isomers cis-9,trans-11 and trans-10,cis-12; each 10 g/d), or both (EFA+CLA). Blood samples were taken to measure changes in FA in blood plasma on d -63, -42, 1, 28, and 56, and in plasma lipid fractions (cholesterol esters, free fatty acids, phospholipids, and triglycerides) on d -42, 1, and 56 relative to calving, and in erythrocyte membrane (EM) on d 56 after calving. Traits related to the acute phase response and inflammation were measured in blood throughout the study. Liver samples were obtained for biopsy on d -63, -21, 1, 28, and 63 relative to calving to measure the mRNA abundance of genes related to the inflammatory response. The concentrations of α-linolenic acid and n-3 FA metabolites increased in lipid fractions (especially phospholipids) and EM due to EFA supplementation with higher α-linolenic acid but lower n-3 metabolite concentrations in EFA+CLA than in EFA treatment only. Concentration of linoleic acid decreased in plasma fat toward calving and increased during early lactation in all groups. Concentration of plasma arachidonic acid was lower in EFA- than in non-EFA-treated groups in lipid fractions and EM. The cis-9,trans-11 CLA increased in all lipid fractions and EM after both CLA treatments. Plasma haptoglobin was lowered by EFA treatment before calving. Plasma bilirubin was lower in EFA and CLA than in CTRL at calving. Plasma concentration of IL-1β was higher in EFA than in CTRL and EFA+CLA at certain time points before and after calving. Plasma fibrinogen dropped faster in CLA than in EFA and EFA+CLA on d 14 postpartum. Plasma paraoxonase tended to be elevated by EFA treatment, and was higher in EFA+CLA than in CTRL on d 49. Hepatic mRNA abundance revealed time changes but no treatment effects with respect to the inflammatory response. Our data confirmed the enrichment of n-3 FA in EM by EFA treatment and the inhibition of n-3 FA desaturation by CLA treatment. The elevated n-3 FA status and reduced n-6:n-3 ratio by EFA treatment indicated a more distinct effect on the inflammatory response during the transition period than the single CLA treatment, and the combined EFA+CLA treatment caused minor additional changes on the anti-inflammatory response.
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Affiliation(s)
- M Gnott
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - L Vogel
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - C Kröger-Koch
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - D Dannenberger
- Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - A Tuchscherer
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | | | - E Trevisi
- Department of Animal Sciences, Food and Nutrition (DIANA), Università Cattolica del Sacro Cuore, 29122 Piacenza, Italy
| | - T Stefaniak
- Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Science, 50-375 Wroclaw, Poland
| | - J Bajzert
- Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Science, 50-375 Wroclaw, Poland
| | - A Starke
- Clinic for Ruminants and Swine, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - M Mielenz
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - L Bachmann
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany
| | - H M Hammon
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
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Effect of a supplement rich in linolenic acid added to the diet of mares on fatty acid composition of mammary secretions and the acquisition of passive immunity in the foal. ACTA ACUST UNITED AC 2016. [DOI: 10.1017/s135772980005880x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AbstractDue to the structure of the placenta in the horse (epitheliochorial) and the as yet un-activated immune system of the foal at birth, the transfer of maternal immunoglobulin G (IgG) is essential in the protection of the young foal until its own immune system develops. The fluidity of intestinal cell membranes may affect the transfer of IgG by receptor mediated endocytosis. In the present experiment we studied the effect of the addition of supplements rich in either alpha-linolenic acid or oleic acid to the diet of the mares starting 1·5 months before foaling and for 1 month after foaling on the passive transfer of IgG and the fatty acid composition of mammary secretions and plasma of foals. Twenty-six mares were allocated to one of two treatment groups (L: linseed supplement, no. = 13 and R: rapeseed supplement, no. = 13) according to date of foaling and live weight to produce two homogeneous groups. Mammary secretions were collected to measure IgG and fatty acid composition. Jugular blood samples were taken from the foals at time 0, 12 h, 24 h, 48 h, 1 week, 2 weeks, 3 weeks and 4 weeks after foaling to measure the concentration of IgG. A subsample of foals was used to measure the IgG absorption coefficient and the plasma fatty acid compositon. There was no effect of dietary treatment on the length of gestation, the production and transfer of IgG. Group L mares produced mammary secretions which were richer in C18: 3 and poorer in C18: 1 than group R mares (P < 0·001). Contrary to expectations the C18: 3 content of blood from foals at birth from both dietary treatments was very low and there was no difference between dietary groups. The percentage of C18: 3 and C18: 2 in fatty acids increased in foal blood only after sucking had occurred, with a difference between dietary groups (L > R). In addition, the percentages of C20: 3 and C20: 4 were higher in the foals at birth than 48 h later (P < 0·001) and at birth they were highest in the R group compared with the L group foals (P < 0·05 and P 0·10, respectively). In conclusion, the attempt to increase the supply of C18: 3 during gestation to foals and to improve the transfer of IgG post partum did not appear to succeed, perhaps because the foal uses C22: 6 (produced from C18: 3) for brain growth.
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Clayton EH, Wilkins JF, Refshauge G, Friend MA. Lower Concentration of n-3 in the Red Blood Cells and Plasma of Lambs when their Dams were Fed a Diet High Compared with Low in n-6 Fatty Acids at Joining. Lipids 2015; 50:883-93. [DOI: 10.1007/s11745-015-4047-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 07/01/2015] [Indexed: 11/28/2022]
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Duvaux-Ponter C, Rigalma K, Roussel-Huchette S, Schawlb Y, Ponter AA. Effect of a supplement rich in linolenic acid, added to the diet of gestating and lactating goats, on the sensitivity to stress and learning ability of their offspring. Appl Anim Behav Sci 2008. [DOI: 10.1016/j.applanim.2008.01.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Renfurm LN, Bandsma RHJ, Verkade HJ, Hulzebos CV, van Dijk T, Boer T, Stellaard F, Kuipers F, Sauer PJJ. Cholesterol synthesis and de novo lipogenesis in premature infants determined by mass isotopomer distribution analysis. Pediatr Res 2004; 56:602-7. [PMID: 15295085 DOI: 10.1203/01.pdr.0000139482.88468.46] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Premature infants change from placental supply of mainly carbohydrates to an enteral supply of mainly lipids earlier in their development than term infants. The metabolic consequences hereof are not known but might have long-lasting health effects. In fact, knowledge of lipid metabolism in premature infants is very limited. We have quantified de novo lipogenesis and cholesterogenesis on d 3 of life in seven premature infants (birth weight, 1319 +/- 417 g; gestational age, 30 +/- 2 wk). For comparison, five healthy adult subjects were also studied. All subjects received a 12-h [1-(13)C] acetate infusion, followed by mass isotopomer distribution analysis (MIDA) on lipoprotein-palmitate and plasma unesterified cholesterol. The fraction of lipoprotein-palmitate synthesized at the end of the infusion period was 5.4 +/- 3.9% in infants, which was in the same range as found in adult subjects on a normal diet, suggesting that hepatic de novo lipogenesis is not a major contributor to fat accumulation in these premature neonates. The fractional contribution of newly synthesized cholesterol to plasma unesterified cholesterol was 7.4 +/- 1.3% after a 12-h infusion. The calculated rate of endogenous cholesterol synthesis was 31 +/- 7 mg/kg/d, a value approximately three times higher than that found in adult subjects (10 +/- 6 mg/kg/d). These results indicate that the cholesterol-synthesizing machinery is well developed in premature infants.
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Affiliation(s)
- Lorraine N Renfurm
- Groningen University Institute for Drug Exploration, Center for Liver, Digestive and Metabolic Diseases, Department of Pediatrics, University Hospital Groningen, 9700 RB Groningen, The Netherlands
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Campbell FM, Gordon MJ, Dutta-Roy AK. Plasma membrane fatty acid-binding protein (FABPpm) of the sheep placenta. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1214:187-92. [PMID: 7918599 DOI: 10.1016/0005-2760(94)90043-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fatty acid-binding protein (FABPpm) has been identified and characterised from sheep placental membranes. Binding of [14C]oleate to placental membranes was found to be time- and temperature-dependent. Addition of a 20-fold excess unlabelled oleic, palmitic, or linoleic acid reduced the binding of [14C]oleate to the membranes to around 50% of total binding, whereas D-alpha-tocopherol at similar concentrations did not affect [14C]oleate binding. This indicates that the binding sites are specific to fatty acids. Specific binding of [14C]oleate was reduced by heat denaturation or trypsin digestion of the membranes, suggesting that the fatty acid-binding sites are protein in nature. FABPpm was then solubilised from sheep placental membranes, and subsequently purified to electrophoretic homogeneity using an oleate-agarose affinity column. The purified FABPpm had an apparent molecular mass of 40 kDa, as determined by SDS-PAGE and by gel permeation chromatography. The [14C]oleate-binding activity of the purified protein was also confirmed by PAGE followed by autoradioblotting. The specific binding for oleate was around 1.5 nmol per mg of membrane protein. Our data indicate the presence of FABPpm in sheep placental membranes.
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Affiliation(s)
- F M Campbell
- Receptor Research Laboratory, Rowett Research Institute, Aberdeen, Scotland, UK
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Weems YS, Vincent DL, Nusser KD, Tanaka Y, Miller-Patrick K, Ledgerwood KS, Weems CW. Effect of prostaglandin F2 alpha on uterine or ovarian secretion of prostaglandins E and F2 alpha in vivo in 90-100 day hysterectomized, intact or ovariectomized pregnant ewes. PROSTAGLANDINS 1993; 46:277-96. [PMID: 8234835 DOI: 10.1016/0090-6980(93)90010-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Vehicle or 8 or 16 mg of PGF2 alpha per 58 kg body weight was given intramuscularly to intact, hysterectomized or ovariectomized 90-100 day pregnant ewes in three separate experiments. Both doses of PGF2 alpha increased PGF2 alpha in ovarian venous plasma compared with controls at 72 hr post treatment in intact (P < or = 0.05) but did not in hysterectomized (P > or = 0.05) 90-100 day pregnant ewes. Concentrations of PGE in ovarian venous blood of intact ewes did not differ (P > or = 0.05) between treatment groups and were equivalent to concentrations of PGE determined in uterine venous plasma. PGE was decreased in ovarian venous plasma by PGF2 alpha in hysterectomized ewes (P < or = 0.07). PGE in uterine venous plasma averaged 6 ng/ml over the 72-hr treatment period in intact and ovariectomized 90-100 day pregnant ewes and was 12 fold greater (P < or = 0.05) than PGF2 alpha which averaged 500 pg/ml in uterine venous plasma. Both PGF2 alpha and PGE increased (P < or = 0.05) by 64 hr in uterine venous plasma of the 8 mg PGF2 alpha-treated intact pregnant ewes. A significant quadratic increase (P < or = 0.05) was observed for PGF2 alpha and PGE in the vehicle and both PGF2 alpha treatment groups of intact ewes at the end of the 72-hr sampling period. It is concluded that the uterus and ovaries secrete significant quantities of PGF but little PGF2 alpha during midgestation. In addition, PGF2 alpha increased uterine secretion of PGE in vivo. PGE may be a placental stimulator of ovine placental secretion of progesterone or PGE may protect placental steroidogenesis from actions of PGF2 alpha.
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Affiliation(s)
- Y S Weems
- Department of Animal Sciences, University of Hawaii, Honolulu 96822
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Shand JH, Noble RC. The lipid composition of ovine placental tissue homogenate and its subcellular fractions. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1984; 79:291-5. [PMID: 6509920 DOI: 10.1016/0305-0491(84)90028-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Homogenates of the placental tissue of near term sheep were separated by differential centrifugation into mitochondrial, microsomal and cytosolic fractions. The relative proportions of the major neutral lipids and phospholipids, together with their fatty acid compositions, were determined in the homogenates and in each subcellular fraction. The cytosolic fraction contained the highest proportion of cholesteryl esters (CEs) and these possessed a fatty acid composition markedly different from the total CEs extracted from the homogenate. Both the mitochondrial and microsomal fractions contained significant proportions of solvent front phospholipid (SFP) and whereas the mitochondrial SFP displayed the relatively unsaturated fatty acid composition characteristic of diphosphatidylglycerol (cardiolipin), the fatty acids of the microsomal SFP were distinctly more saturated. These results are compared with those obtained from other mammalian tissues, both ruminant and non-ruminant, and discussed in terms of the function of the components of the subcellular fractions.
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Shand JH, Noble RC. The characterization of the linoleic acid desaturation and elongation system in ovine placental tissue. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1983; 15:1367-71. [PMID: 6642054 DOI: 10.1016/0020-711x(83)90028-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The desaturation and elongation of linoleic acid has been studied in homogenates and in subfractions of ovine placental tissue. The reaction was characterized in terms of pH and temperature optima, time course and protein concentration. Activity was found to be confined to the 11,000 g supernatant fraction of the tissue and the results suggest that the enzymes are membrane bound. The cytosolic fraction and ATP were required for full activity and the reaction was inhibited by cyanide. The properties of the reaction are compared with those of other desaturation systems and their implications with regard to possible reaction mechanisms are discussed.
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