1
|
Affiliation(s)
- D E Vance
- Lipid and Lipoprotein Research Group, University of Alberta, Edmonton, Canada
| | | |
Collapse
|
2
|
Gonmori K, Morita T, Mehendale HM. Effect of chlorphentermine on incorporation of [14C]choline in the rat lung phospholipids. Lipids 1986; 21:230-4. [PMID: 3702614 DOI: 10.1007/bf02534827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of chlorphentermine (CP) treatment (50 mg/kg/day, per os [po]) on the incorporation of [14C]choline into rat lung phospholipid was studied. Total phospholipid content was increased 2.0-fold and 1.7-fold after seven and 14 days, respectively, compared with the pair-fed rats. The incorporation of [14C]choline into phosphatidylcholine (PC) was significantly inhibited by either seven or 14 days of CP treatment. Nevertheless, the PC content was significantly increased by day 7 and stayed elevated at day 14 of CP treatment. Choline and phosphorylcholine contents were significantly decreased by the CP treatment. These results suggest that the higher accumulation of PC is due to inhibition of enzymes involved in the hydrolysis of phospholipids rather than to a stimulation of the phospholipid synthesis.
Collapse
|
3
|
|
4
|
Smith JD. Effect of modification of membrane phospholipid composition on the activity of phosphatidylethanolamine N-methyltransferase of Tetrahymena. Arch Biochem Biophys 1983; 223:193-201. [PMID: 6859857 DOI: 10.1016/0003-9861(83)90585-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The activity of phosphatidylethanolamine N-methyltransferase is less than 10% of control levels in microsomes prepared from the ciliate protozoan Tetrahymena thermophila whose phospholipid composition had been altered by being cultured on media containing phosphonic acids. The primary modification obtained is decreased levels of phosphatidylethanolamine (J.D. Smith and D.A. Giegel, Arch. Biochem. Biophys., 206, 420-423 (1981) and 213, 595-601 (1982)). The enzyme protein is present in these cells at normal levels since addition of the substrate phosphatidylethanolamine to the assay system restores enzyme activity of the lipid-modified microsomes to control levels, while the enzyme from control microsomes is not affected by added phosphatidylethanolamine. The microsomal enzyme is inhibited by the anionic phospholipids cardiolipin, phosphatidylglycerol, and phosphatidylinositol and by lysophosphatidylethanolamine while it is activated only by phosphatidylserine in addition to the substrates phosphatidylethanolamine and phosphatidyldimethylethanolamine. The added phosphatidylethanolamine acts directly as a substrate for the methyltransferase rather than acting by merely stimulating utilization of endogenous lipid since added phosphatidyl[14C]ethanolamine is directly converted to phosphatidylcholine. The results suggest that the technique of phosphonic acid-induced modification of lipid composition will be useful for the study of other membrane-bound enzymes.
Collapse
|
5
|
Mori K, Taniguchi S, Kumada K, Nakazawa K, Fujiwara M, Fujiwara M. Enzymatic properties of phospholipid methylation in rabbit platelets. Thromb Res 1983; 29:215-24. [PMID: 6845277 DOI: 10.1016/0049-3848(83)90143-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The enzymatic properties of phospholipid methylation in rabbit platelets were examined using S-adenosyl-L-[methyl-3H]methionine as a substrate. pH optimum for the methylation was around 10.5 under Tris-HCl and glycine-NaOH buffer systems. When Tris-HCl buffer was replaced by phosphate buffer, pH optimum shifted to around 8.0 and the methylation was increased approximately threefold, compared with that in the case of Tris-HCl buffer at pH 8.0. The formation of the 3H-methylated phospholipids was increased by addition of exogenous phosphatidyl-N-monomethylethanolamine or phosphatidyl-N,N-dimethylethanolamine, intermediates of the biosynthesis of phosphatidylcholine from phosphatidylethanolamine. However, the increase in product formations by addition of exogenous intermediates was all but equal under Tris-HCl and phosphate buffer systems at pH 8.0. These results suggest that phosphate ion stimulates the first step of the successive methylation to form phosphatidyl-N-monomethylethanolamine from phosphatidylethanolamine. The methylation in platelets was inhibited to 30% of the basal value with Ca2+ (0.2 mM). However, Ca2+ showed different effects on the methylation in various tissues (activation to 150% of the basal value in the adrenal gland and slight inhibition to 82-88% of corresponding basal values in the liver, lung, kidney and brain).
Collapse
|
6
|
Chapter 1 Phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0167-7306(08)60005-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
|
7
|
Abstract
The highly pulmonary concentration of 1,2-dipalmitoyl-sn-glycerol-3-phosphorylcholine (dipalmitoyllecithin) and its implication as an important component of lung surfactant have promoted investigation of phospholipid metabolism in the lung. This review will set the contents including recent informations for better understanding of phospholipid metabolism of the lung in normal state (physiological significances of lung phospholipids, characteristics of phospholipids in lung tissue and alveolar washing, biosynthetic pathways of dipalmitoyllecithin, etc.) as well as in toxic states (pulmonary oxygen toxicity, etc.) and in diseased states (idiopathic respiratory distress syndrome, pulmonary alveolar proteinosis, etc.) Since our main concern has been to clarify the most important route for supplying dipalmitoyllecithin, this review will be focused upon the various biosynthetic pathways leading to the formation of different molecular species of lecithin and their potential significance in the normal, toxic, and diseased lungs.
Collapse
|
8
|
Schneider WJ, Vance DE. Conversion of phosphatidylethanolamine to phosphatidylcholine in rat liver. Partial purification and characterization of the enzymatic activities. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)50670-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
9
|
Eriksson LC, DePierre JW, Dallner G. Preparation and properties of microsomal fractions. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0362-5478(78)90019-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
10
|
Johannesen K, Depierre JW, Bergstrand A, Dallner G, Ernster L. Preparation and characterization of total, rough and smooth microsomes from the lung of control and methylcholanthrene-treated rats. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 496:115-35. [PMID: 402160 DOI: 10.1016/0304-4165(77)90120-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Optimal conditions for the preparation of relatively pure microsomes and microsomal subfractions from rat lung have been determined. The most importnat of these conditions is homogenization of a 20% (w/v) suspension of lung tissue in 0.44 M sucrose/1% (w/v) bovine serum albumin with four up-and-down strokes at 440 rev./min in a Potter-Elvehjem homogenizer. The 10000 X g supernatant prepared from this homogenate can be centrifuged at 105000 X g to obtain total microsomes or subfractionated into rough and smooth microsomes on a Cs+-containing discontinuous sucrose gradient. The total, rough and smooth microsomes have been characterized in terms of their chemical composition, enzymatic activity, and morphology. These preparations should prove useful in studies of various enzymes in lung (e.g. benzpyrene monooxygenase, epoxide hydrase, enzymes of phospholipid and ascorbic acid synthesis) and in subfractionations designed to reveal heterogeneites in the lateral plane of the lung endoplasmic reticulum.
Collapse
|
11
|
Abstract
An isolated lung ventilated with pulses of negative pressure and perfused through the pulmonary vasculature was utilized for the study of 3-sn-phosphatidylcholine synthesis. The perfusion fluid consisted of a Krebs-Ringer phosphate buffer with 6% bovine serum albumin, pH 7.4, and the appropriate substrate. The simultaneous incorporation of (1-14C) palmitate and (2-3H) glycerol and the simultaneous incorporation of (CH3-14C) choline and (CH3-3H) methionine were examined. From these experiments it is concluded: 1) lung tissue incorporates (2-3H) glycerol into 3-sn-phosphatidylcholine to a greater extent than any other lipid examined; 2) both choline and methionine contribute to the synthesis of 3-sn-phosphatidylcholine, and 50-70% of the label in its nitrogen base is derived from choline and 30-50% from methionine; and 3) a high PO2 appears to reduce the synthesis of 3-sn-phosphatidylcholine.
Collapse
|
12
|
Rooney SA, Motoyama EK. Studies on the biosynthesis of pulmonary surfactant. The role of the methylation pathway of phosphatidylcholine biosynthesis in primate and non-primate lung. Clin Chim Acta 1976; 69:525-31. [PMID: 820492 DOI: 10.1016/0009-8981(76)90127-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The relative importance of the choline incorporation and methylation pathways of phosphatidylcholine biosynthesis was studied in the rat, rabbit, rhesus monkey and human lung. In vitro studies showed that phosphatidylethanolamine methyltransferase activity in the lungs of all species was only a fraction of that in rat liver. In vivo experiments were carried out to study the incorporation of an intravenously administered equimolar mixture of L-[methyl-14C]-methionine and [methyl-3H] choline into lipid inthe lung and liver of the rabbit and monkey. Over 90% of the total radioactivity incorporated into lipid was found in phosphatidylcholine. In the liver, methionine incorporation was 40--71% of that of choline in the rabbit and 99--120% in the monkey while in the lungs of both species it was less than 3%. On a weight basis, choline incorporation in the lung was 2--4 times that in the liver. These findings suggest that the methylation pathway is of little quantitative significance in the biosynthesis of phosphatidylcholine in primate and non-primate lung.
Collapse
|
13
|
|
14
|
Rooney SA, Page-Roberts BA, Motoyama EK. Role of lamellar inclusions in surfactant production: studies on phospholipid composition and biosynthesis in rat and rabbit lung subcellular fractions. J Lipid Res 1975. [DOI: 10.1016/s0022-2275(20)34491-6] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
15
|
|
16
|
Godinez RI, Sanders RL, Longmore WJ. Phosphatidylglycerol in rat lung. I. Identification as a metabolically active phospholipid in isolated perfused rat lung. Biochemistry 1975; 14:830-4. [PMID: 1115773 DOI: 10.1021/bi00675a029] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Isolated rat lungs when perfused for 2 hr with [U-14]glucose, [2-14C]lactate, or [u-14]acetate, were found to contain a phos pholipid which represented a small percentage of the total phospholipid (3.9 per cent), and possessed the highest specific activity of any phospholipid. Using chromatographic, chemical, and mass spectral analysis, the phospholipid has been identified as phosphatidylglyercol. When [2-14C]lactate was present in the perfusion medium, 15.3 per cent of the lactate incorporated into phospholipids was incorporated into phosphatidylglyerol with a relative specific activity of 5.1 compared to phosphatidylcholine, 1.0, and phosphatidylethanolamine, 0.5. Phosphatidylglycerol also had the highest specific activity when lungs were perfused with [1-14C]acetate and [U-14]glucose. While the significance of the content and apparent metabolic activity of phosphatidylglycerol are unknown, its possible role in stabilizing the surfactant complex of lung is discussed.
Collapse
|
17
|
Exploitable Biochemical Approaches for the Evaluation of Toxic Lung Damage. ACTA ACUST UNITED AC 1975. [DOI: 10.1016/b978-0-12-107606-1.50011-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
18
|
|
19
|
Masao A, Toyoaki A, Kimiyoshi O. The formation of lecithin from lysolecithin in rat lung supernatant. ACTA ACUST UNITED AC 1972. [DOI: 10.1016/0005-2760(72)90094-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
Page-Roberts BA. Preparation and partial characterization of a lamellar body fraction from rat lung. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 260:334-8. [PMID: 4335144 DOI: 10.1016/0005-2760(72)90046-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
21
|
Vereyken JM, Montfoort A, van Golde LM. Some studies on the biosynthesis of the molecular species of phosphatidylcholine from rat lung and phosphatidylcholine and phosphatidylethanolamine from rat liver. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 260:70-81. [PMID: 5012455 DOI: 10.1016/0005-2760(72)90075-6] [Citation(s) in RCA: 114] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
22
|
van den Bosch H, van Golde LM, van Deenen LL. Dynamics of phosphoglycerides. ERGEBNISSE DER PHYSIOLOGIE, BIOLOGISCHEN CHEMIE UND EXPERIMENTELLEN PHARMAKOLOGIE 1972; 66:13-145. [PMID: 4566505 DOI: 10.1007/3-540-05882-6_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
23
|
Toyoaki A, Masao A, Tatsuo A. Studies on the biosynthetic pathways of molecular species of lecithin by rat lung slices. ACTA ACUST UNITED AC 1971. [DOI: 10.1016/0005-2760(71)90015-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
24
|
|
25
|
Abstract
1. Labelled precursors of choline, namely ethanolamine, dimethylaminoethanol and methionine and also labelled choline itself were injected intraperitoneally into the adult female rat and the incorporation into lipids and water-soluble fractions was traced in liver, blood and brain. 2. No significant free choline was detected and no labelling of the phosphorylcholine of blood. There was, however, considerable labelling of the phosphorylcholine of brain and liver. 3. After intracerebral injection, [1,2-(14)C]dimethylaminoethanol was rapidly phosphorylated and converted into phosphatidyldimethylaminoethanol, presumably by the cytidine pathway. 4. In view of the pattern of labelling and the amount of phosphatidylcholine in the tissues examined, it seems highly likely that choline is transported to the brain by the blood in a lipid-bound form.
Collapse
|
26
|
Smith JD, Law JH. Phosphatidylcholine biosynthesis in Tetrahymena pyriformis. BIOCHIMICA ET BIOPHYSICA ACTA 1970; 202:141-52. [PMID: 5417179 DOI: 10.1016/0005-2760(70)90225-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|