The content of phospholipids and their fatty acid composition were followed in the hearts of two inbred strains of rats: IR, resistant against the development of isoprenaline-induced myocardial lesions and IS, sensitive to their development. In the hearts of rats of the resistant strain, a lower content of phosphatidylcholine and its plasmalogen fraction was found compared to IS rats. The total amount of phospholipids was only insignificantly lower in IR rats. Greater differences were found in individual fatty acids. The most important finding concerned lower arachidonic acid and higher linoleic acid content in heart phospholipids of IR rats. These differences were exactly opposite to changes reported in the literature in animals known to have a higher resistance against myocardial damage due to various interventions. Our results do not support the hypothesis claiming the importance of changes in phospholipids and their FA composition for the resistance of the heart against the development of necrotic lesions.
The effects of drought on thylakoid acyl lipid composition, photosynthetic capacity (P max), and electrolyte lekage were evaluated in two-months-old peanut cultivars (57-422, 73-30, GC 8-35) growing in a glasshouse. For lipid studies, plants were submitted to three treatments by withholding irrigation: control (C), mild water stress (S1), and severe water stress (S2). Concerning membrane and photosynthetic capacity stability, drought was imposed by polyethylene glycol (PEG 600). In the cv. 73-30 a sharp decrease in the content of thylakoid acyl lipids was observed, already under S1 conditions, whereas cv. 57-422 was strongly affected only under S2. Cv. GC 8-35 had the lowest content of acyl lipids under control conditions, a significant increase under S1 conditions, and only under S2 a decrease occurred. Thus concerning lipid stability, cv. 73-30 was the most sensitive. Among lipid classes, phospholipids and galactolipids were similarly affected, as was MGDG relatively to DGDG. Water deficit imposed by PEG induced a higher increase in electrolyte leakage in cv. 73-30 than in the other cvs. A positive relationship between acyl lipid concentration and membrane integrity was found in all studied cvs. A positive association between acyl lipid concentration, membrane integrity, and P max was found in the cvs. 57-422 and 73-30. and J. A. Lauriano ... [et al.].
The heart phospholipid content and fatty acid composition were examined in adult rats after four weeks of feeding lipid-supplemented diets (20 g % w/w) containing sunflower oil-lard (1:1) mixture (SL group) or margarine (M group). Our results showed a decreased cardiolipin content and distribution in both experimental groups and an increased lysophosphatidylcholine and phosphatidylcholine content and distribution in the SL group with a tendency to lower phosphatidylcholine/phospatidylethanolamine ratio in both experimental groups. In the SL group, the content of saturated fatty acids was higher and that of monounsaturated fatty acids was lower than in the control group. The M group showed inverse results. The content of saturated fatty acids was lower and that of monounsaturated was higher than in the control group. Polyunsaturated n-6 fatty acids were decreased in both experimental groups and n-3 fatty acids were increased in the M group. Feeding lipid-supplemented diets reduced n-6/n-3 and 20:4/22:6 ratios in the M group. The polyunsaturated/saturated fatty acid ratio was lower in the SL and higher in indicating the M group than in the control group. Our results are in agreement with the other reports indicating that the heart is sensitive to diet-induced lipid alterations.
Normal increase in hemodynamic load during early postnatal life is associated with heart growth and maturation of membrane structures that is accompanied by remodeling of membrane protein and lipid components. This review describes remodeling of phospholipids (PL) in rat myocardium during normal postnatal development and during accelerated cardiac growth induced by additional workload (aorta constriction, chronic hypoxia and hyperthyroidism) imposed on the heart early after birth. Normal physiological load after birth stimulates the development of membrane structures and synthesis of PL. While hyperthyroidism accelerates these processes, pressure overload has an inhibitory effect. These changes primarily influence the maturation of mitochondrial membranes as cardiolipin is one of the most affected PL species. The most sensitive part of PL structure in their remodeling process are PL acyl chains, particularly polyunsaturated fatty acids that are the key components determining the basic physicochemical properties of the membrane bilayer and thus the function of membrane-bound proteins and membrane-derived signaling lipid molecules. It is evident that PL remodeling may significantly influence both normal and pathological postnatal development of myocardium., F. Novák ... [et al.]., and Obsahuje seznam literatury
A pressure overload was induced in 2-day-old male rats by abdominal aortic constriction, and the phospholipid composition of the left ventricle (LV) and the right ventricle (RV) were determined. Sixty days after the surgery, body weights was lower and LV weight were higher in aorta-constricted (AC) rats in comparison with sham- operated animals. Increased ventricular/body weight ratios indicated a significant degree of hypertrophy of LV and smaller hypertrophy of RV. The concentrations of total phospholipids (PL), choline phosphoglycerides (PC), ethanolamine phosphoglycerides (PE), diphosphatidylglycerol (DPG) and phosphatidylinositol (PI) were decreased in both ventricles of AC rats. The concentrations of sphingomyelin (SM) and plasmalogen PE (PLPE) increased in LV only. The changes in phospholipid composition in the developing pressure-overloaded myocardium may contribute to altered membrane functions connected with heart hypertrophy.
Alterations in phospholipid metabolism in blood elements have been proposed as the possible biochemical marker of schizophrenia. In the present study, we investigated the composition and membrane distribution of phospholipids in platelets of drug-free schizophrenic patients and controls. We have demonstrated that platelets of drug-free schizophrenics have significantly higher cytosolic Ca2+ levels in comparison with healthy controls. Platelets of drug-free schizophrenic patients have a lower content of phosphatidylinositol (PI). After thrombin activation, PI is the target of phospholipase C instead of phosphatidylinositol 4,5-bisphosphate (PIP2), which is hydrolyzed in platelets of controls. Alterations in the distribution of phospholipids were found in the plasma membrane of platelets of schizophrenic patients. We suggest that alterations in phospholipid metabolism might be evoked by a disturbance of calcium homeostasis in schizophrenic patients.
Chill tolerance (time of survival at -5°C) increased in non-diapausing (reproducing) adults of Pyrrhocoris apterus after a gradual, 4-week-long decrease in ambient temperature from 25° to 0°C. The level of chill tolerance attained after cold-acclimation was considerably lower than that in similarly cold-acclimated diapausing adults. Some physiological changes accompanied the cold-acclimation, irrespective of developmental state (diapause vs. reproduction). They were: A decreased oxygen consumption, loss of body water, an increased haemolymph osmolality, an increased proportion of phosphatidylethanolamines vs. a decreased proportion of phosphatidylcholines in membrane phospholipids, and an increased proportion of linoleic vs. a decreased proportion of oleic acid in phosphatidylethanolamines. Such changes could contribute to the limited potential for cold-acclimation found in non-diapausing insects. Other physiological changes appeared to require the induction of diapause prior to cold-acclimation. They were: Down regulation of ice nucleators resulting in a lowering of the individual supercooling point, synthesis and accumulation of specific "winter" polyols, an increased proportion of palmitic acid in membrane phospholipids; and regulation of the concentrations of Na+ and K+ in the haemolymph. The potential contributions of these changes to the cold hardiness of P. apterus are discussed.
Increasing hemodynamic load during early postnatal development leads to rapid growth of the left ventricular (LV) myocardium, which is associated with membrane phospholipid (PL) remodeling characterized by n-3 polyunsaturated fatty acids (PUFA) accumulation. The aim of this study was to examine the influence of additional workload imposed early after birth when ventricular myocytes are still able to proliferate. Male Wistar rats were subjected to abdominal aortic constriction (AC) at postnatal day 2. Concentrations of PL and their fatty acid (FA) profiles in the LV were analyzed in AC, sham-operated (SO) and intact animals on postnatal days 2 (intact only), 5 and 10. AC resulted in LV enlargement by 22 % and 67 % at days 5 and 10, respectively, compared with age-matched SO littermates. Concentrations of phosphatidylcholine, cardiolipin, phosphatidylinositol, phosphatidylethanolamine, phosphatidylserine and sphingomyelin decreased in AC myocardium, albeit with different time course and extent. The main effect of AC on FA remodeling consisted in the accumulation of n-3 PUFA in PL. The most striking effect of AC on FA composition was observed in phosphatidylinositol and cardiolipin. We conclude that excess workload imposed by AC inhibited the normal postnatal increase of PL concentration while further potentiating the accumulation of n-3 PUFA as an adaptive response of the developing myocardium to accelerated growth., F. Novák, ... [et al.]., and Obsahuje seznam literatury
a1_Antiphospholipid antibodies (APAs) are characterized as a heterogeneous population of autoantibodies directed against different target antigens, predominantly anionic phospholipids or phospholipid-containing structures. The presence of APAs has been strongly associated with a variety of clinical disorders including adverse pregnancy complications such as spontaneous abortions, pregnancy-induced hypertension, preeclampsia and intrauterine growth retardation. The purpose of this study was to compare the prevalence of anticardiolipin antibodies (ACAs), which are routinely examined, with APAs directed against phosphatidylserine (APS), phosphatidylinositol (API), phosphatidylethanolamine (APE) and phosphatidylcholine (APC) in the sera of pregnant women. We examined 410 serum samples of pregnant women hospitalized in the department for pathological pregnancies. They underwent prenatal biochemical screening of fetal congenital abnormalities in the first and the second trimester of gravidity. Anticardiolipin IgG and IgM were measured using commercial ELISA kits (ImmuLisaTM Anti-Cardiolipin Antibody), whereas APS, APE, API and APC were determined by our modified ELISA kit. Among 410 pregnant women we found 21 patients (5.1 %) positive for ACA IgG (>20 GPL) and 30 patients (7.3 %) positive for ACA IgM (>10 MPL). It was found that 7.8 % of pregnant women had at least one high-titer APA IgG and 9.8 % high-titer APA IgM. One third of ACA IgG or IgM positive sera contained polyspecific autoantibodies reactive to at least two various phospholipids. In the group of IgG ACA positive women, 28.6 % patients were positive for APS, 28.6 % were positive or moderately positive for API, 23.8 % for APC and 19 % for APE. In the group of IgM ACA positive women, 33.3 % were also positive for APS, 26.7 % for APE, 26.7 % for API and 23.3 % for APC were present., a2_IgG and IgM ACA negative patients exhibited a significantly lower incidence of other APA than the group of ACA positive pregnant women. It still remains to clarify if the routine examination of APA reacting with other anionic and zwitterionic antigens other than cardiolipin would improve the probability of identifying women liable to adverse pregnancy complications., L. Fialová, L. Mikulíková, I. Matouš-Malbohan, O. Benešová, A. Zwinger., and Obsahuje bibliografii
We investigated the effect of isoprénaline (IPRO), a /J-mimetic catecholamine, on incorporation of (32P)Pi into phospholipids of the mouse left ventricle in uiuo. All experimental groups of male mice received an injection of (32p)pi ^250 MBq x kg“1 b.w.) intraperitoneally two hours prior to sacrifice. A single dose of IPRO (5 mg x kg-1 b.w.) was injected one hour before killing. IPRO increased the specific radioactivity of phosphatidylcholine (PC) by a factor of 1.8, diphosphatidylglycerol (DPG) 2.1, sphingomyelin (SM) 3.5, phosphatidylinositol (PI) 1.7, phosphatidylserine (PS) 1.7, phosphatidylglycerol (PG) 1.7, phosphatidic acid (PA) 2.0 compared to control values. On the other hand, IPRO is also known to stimulate phospholipid degradation by activation of phospholipase A2. That is why we used mepacrine (50 mg x kg“1 b.w.), a phospholipase inhibitor, to find a possible link between biosynthesis and degradation of phospholipids. Pretreatment with mepacrine two hours prior to sacrifice suppressed IPRO stimulated incorporation of (32P)Pi into phospholipids nearly to control levels. Mepacrine itself did not significantly influence the specific radioactivity of phospholipids. We conclude that phospholipase A2 inhibitor, mepacrine, is able to prevent IPRO-stimulated ¡corporation into phospholipids, suggesting a feedback relation between their biosynthesis and degradation in the myocardium.