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1.
Three 1-yr-old swine and two 2.5-wk-old swine were fed a fat-free diet for 1 month and 5 months, respectively. The hepatic phosphatidylcholine and phosphatidylethanolamine were fractionated by silver ion thin-layer chromatography. A distinctive feature of the chromatographic procedure was the development of the chromatograms at low temperatures: -10 degrees C for phosphatidylcholine and 4 degrees C for phosphatidylethanolamine. The chromatographic fractions were hydrolyzed with phospholipase A(2), and the fatty acids were characterized. Significant concentrations of odd-chain saturated and unsaturated fatty acids were found in the swine deprived of fat for 5 months. The major molecular species of phosphatidylcholine in both groups contained monoenoic fatty acids: 16:0/18:1(n - 9), 18:0/18:1(n - 9), and 18:1(n - 9)/18:1(n - 9). Their concentrations changed only slightly with the diet. The molecular species of phosphatidylethanolamine were more sensitive to dietary changes. In the swine deprived of fat for 1 month, about 50% of the molecular species of phosphatidylethanolamine contained tetraenoic fatty acids: 16:0/20:4(n - 6), 18:0/20:4(n - 6), and 18:1(n - 9)/20:4(n - 6). The phosphatidylethanolamine of animals deprived of fat for 5 months contained only 3% molecular species with tetraenoic acids, 18:0/20:4(n - 6), but 36% molecular species with trienoic acids: 18:0/20:3(n - 9), 18:1(n - 9)/20:3(n - 9), 18:0/19:3(n - 8), 16:0/20:3(n - 9), and 17:0/20:3(n - 9). Doubly unsaturated species, such as 18:1(n - 9)/18:1(n - 9), 18:1(n - 9)/20:3(n - 9), and 18:1(n - 9)/20:4(n - 6), were found in both groups of swine, although their total concentrations were higher in the group deprived of fat for a longer period. 相似文献
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3.
Padilla Jaime; Garcia-Villalon Angel Luis; Fernandez Nuria; Monge Luis; Gomez Bernardino; Dieguez Godofredo 《Journal of applied physiology》1998,85(6):2205-2212
To analyze the effect of hyperthermia on thevascular response, the isometric response of isolated rabbit femoralartery segments was recorded at 37°C and hyperthermia (41 and44°C). Contraction to potassium (5 × 103-5 × 102 M) was significantlygreater at 41 and 44 than at 37°C and increased by inhibition ofnitric oxide (NO) synthesis withN-nitro-L-arginine(L-NNA;104 M) or endotheliumremoval at 37°C but not at 41 or 44°C. Norepinephrine (109-104M) produced a concentration-dependent contraction greater at 41 or 44 than at 37°C and not modified by endothelium removal orL-NNA at either temperature.Phenylephrine(109-104M) produced a contraction increased by warming to 44°C but not to41°C. The specific2-adrenoceptor agonist BHT-920produced a weak contraction, reduced by the1-adrenoceptor antagonist prazosin (106 M) andincreased at 44°C but not at 41°C. The concentration-dependent contraction to endothelin-1 (ET-1;1011-107M) was increased by warming to 41 and 44°C and by endothelium removal or L-NNA at 37°C butnot at 41 or 44°C. Response to ET-1 was reduced by endothelinETA-receptor antagonist BQ-123(105 M) andETB-receptor antagonist BQ-788(105 M). In arteriesprecontracted with ET-1(108-3 × 108 M), relaxation tosodium nitroprusside(108-104M) was increased at 41 and 44°C vs. at 37°C, but that of ACh (108-104M) or adenosine(108-104M) was not different at all temperatures studied. Relaxation to ACh,but not adenosine, was reduced similarly byL-NNA at all temperaturesstudied. These results suggest hyperthermia in muscular arteries mayinhibit production of, and increase dilatation to, NO, resulting inunchanged relaxation to ACh and increased constriction to KCl and ET-1,and may increase constriction to stimulation of1-adrenoceptors byNO-independent mechanisms. 相似文献
4.
A Baruffaldi A C Puviani 《Bollettino della Società italiana di biologia sperimentale》1983,59(2):176-181
The effects of epinephrine injected intraperitoneally (5 mg/kg body weight) on the catfish carbohydrate metabolism were studied. Epinephrine caused a very high and persisting hyperglycemia, the highest value of which was 340 +/- 21 mg/100 ml of blood (control value: 75 +/- 6 mg/100 ml) at 24th hour after the administration. Moreover, epinephrine caused glycogenolysis in liver: from 127 +/- 10 to 95 +/- 8 mg/g of tissue. In white muscle the lowering of glycogen happened just after the epinephrine injection and reached the lowest value (1,6 +/- 0,3 mg/g) at 2,5 hours after the administration (control value: 2,9 +/- 0,4 mg/g). A glycogen decrease took place in red muscle with a great delay, but was still present 48 hours after administration (control value: 17,5 +/- 1,8 mg/g; sample value: 11,2 +/- 3,2 mg/g). The increase of glucose level in blood could be referred to glycogenolytic processes in liver. As far as musculature is concerned, red muscle probably plays a role in recovering the glycogen level in white muscle. 相似文献
5.
目的:研究染料木黄酮对体外培养乳鼠颅盖骨成骨细胞增殖分化的影响。方法:取乳鼠颅盖骨,采用胶原-胰蛋白酶消化法,进行颅骨成骨细胞培养,取第二代成骨细胞,添加10^-5~10^-7mol/L染料木黄酮,在CO2孵箱中培养48h和72h后MTT比色法测定细胞增殖,培养72h采用^3H-TdR和^H-Pro掺入实验测定DNA和胶原合成。用试剂盒检测细胞裂解液碱性磷酸酶(ALP)活性。结果:染料木黄酮明显增加成骨细胞MTT的吸光度值、^3H-TdR和^3H-Pro的掺入,增加成骨细胞碱性磷酸酶活性。结论:染料木黄酮促进体外培养的乳鼠颅盖骨成骨细胞DNA和胶原的合成,促进增殖和分化。 相似文献
6.
Laron Z Silbergeld A Kauli R 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2012,69(3):255-259
The differential growth effects of hGH and IGF-I on the upper/lower (U/L) body segment in relation to height (Ht) were analyzed in 15 patients with isolated Growth hormone deficiency (IGHD,:7M, 8F) mean age 5.0 +/- 3.2 (SD) years treated with hGH; 21 patients with multiple pituitary hormone deficiency including growth hormone (MPHD: 14M, 7F) aged 10.0 +/- 3.8, treated with hGH; 9 patients with Laron Syndrome (LS) (4M,5F) aged 6.9 +/- 5.6 years treated with IGF-I; 9 boys with intrauterine growth retardation (IUGR) aged 6.3 +/- 1.25 years treated by hGH; and 22 boys with idiopathic short stature (ISS) aged 8.0 +/- 1.55 years treated by hGH. The dose of hGH was 33 microg/kg/day, that of IGF-I 180-200 microg/kg/day. RESULTS: the U/L body segment ratio in IGHD patients decreased from 2.3 +/- 0.7 to 1.1 +/- 0.7 (p <0.001), and the Ht SDS increased from -4.9 +/- 1.3 to 2.3 +/- 1 (p < 0.001) following treatment. In MPHD patients the U/L body segment decreased from 1.1 +/- 1.1 to -0.6 +/- 1.0 (p < 0.001), and the Ht SDS increased from -3.3 +/- 1.4 to -2.5 +/- 1.0 (p < 0.009). In the LS group the U/L body segment ratio did not change with IGF-I treatment but Ht improved from -6.1 +/- 1.3 to -4.6 +/- 1.2 (p < 0.001), The differential growth response of the children with IUGR and with ISS resembled that of the children with LS. CONCLUSIONS: hGH and IGF-I act differentially on the spine and limbs. 相似文献
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To increase tissue glycogen content many athletes use anabolic androgenic steroids (AAS). However, the literature concerning the effects of androgens on glycogen metabolism is conflicting. This study aimed to determine the influence of training and AAS on body weight (bw), triglycerides, glucose, tissue glycogen and transaminases levels. Male Wistar rats, randomized into four groups (sedentary vehicle (SV), sedentary AAS (SA), trained vehicle (TV) and trained AAS (TA)), were treated with nadrolone (5 mg/Kg, 2x/week, i.m.) or vehicle. Trained rats performed jumps into water (4 sets, 10 repetitions, 30 sec rest) carrying a 50-70% body wt-load strapped to the chest (5 days/week,6 weeks). Two days after the last session, the animals were killed (bifatorial ANOVA+Tukey test; P < 0.05). Trained animals presented lower bw (TV:345+/-7 vs. SV:380+/-7 and TA:328+/-4 vs SA:370+/-11 g) and triglycerides levels (TV:77+/-3 vs. SV:98+/-4 and TA:79+/-3 vs. SA:98+/-8 mg/dL) and higher glycogen content in liver (TV:5.3+/-0.2 vs. SV:3.9+/-0.1 and TA:5.3+/-0.3 vs. SA:4.6+/-0,2 mg/100 mg) and in gastrocnemious (TV:0.70+/-0.02 vs. SV:0.49+/-0.01 and TA:0.73+/-0.03 vs. SA:0.57+/-0.02 mg/100 mg) than sedentary ones. In the cardiac muscle, the association between training and AAS increased glycogen content (TA:0.19+/-0.01 > SV:0.13+/-0.01=TV:0.13+/-0.01=SA:0.14+/-0.01 mg/100 mg). In the soleus AAS increased glycogen (SA:0.53+/-0.03 vs. SV:0.43+/-0.01 and TA:0.58+/-0.02 vs. TV:0.48+/-0.01 mg/100 mg). Exercise training and AAS had no effect on blood glucose and transaminases levels. Training and AAS effects on glycogen supercompensation are tissue-dependent and the effects of association between them were only observed in the cardiac muscle. These data emphasize the necessity of more studies to confirm greater effects of AAS than those promoted by physical exercise. 相似文献
8.
Heckman K. A. Nave L. E. Bowman M. Gallo A. Hatten J. A. Matosziuk L. M. Possinger A. R. SanClements M. Strahm B. D. Weiglein T. L. Rasmussen C. Swanston C. W. 《Biogeochemistry》2021,156(1):57-58
Biogeochemistry - A correction to this paper has been published: https://doi.org/10.1007/s10533-021-00785-9 相似文献
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Ponzo OJ Cresta MA Rondina D Szwarcfarb B Basabe JC Scacchi P 《Neuro endocrinology letters》2000,21(6):441-446
OBJECTIVE AND DESIGN: the objective of this study performed in adult male rats was to determine the alteration in glycemic, insulin and gonadotrophin luteinizing hormone secretion, and noradrenaline pancreatic concentration caused by fasting (F) and aproteic diet (Ap) during 7 and 21 days respectively, as well as the recovery after 24-hour refeeding with control diet (Co). RESULTS: a significant decrease in glycemic levels was only achieved through fasting (F: 86 +/- 5.1 mg %), when compared with controls (Co: 107 +/- 5 mg %). In spite of the high levels of carbohydrates (89%) present in the aproteic diet, the animals fed with this diet showed no differences in glycemic levels (Ap: 120.3 +/- 12.2 mg %), compared with controls. As a result of fasting and aproteic diet, there was a significant decrease in insulin (F: 8.67 +/- 1.36; Ap: 5.7 +/- 0.67; Co: 31 +/- 3.4 uU/ml) and LH levels (F: 10.175 +/- 1.74; Ap: 13.7 +/- 4; Co: 29.83 +/- 4.91 ng/ml). The refed recovered insulin (FR: 50.57 +/- 6.63; ApR: 43.5 +/- 6.85 uU/ml), but not LH levels (FR: 14.25 +/- 3.54; ApR: 13.03 +/- 4.25 ng/ml). A significant increase was observed in the pancreatic noradrenaline concentration (P<0.001) of rats receiving aproteic diet (889.9 +/- 34.65 ng/mg tissue) and fasting during 7 days (827.5 +/- 55.7 ng/mg tissue), compared with controls (531.1 +/- 48.6 ng/mg tissue). CONCLUSIONS: fasting and aproteic diets altered gonadal and metabolic control. When returning to a normal nutritional condition, only the metabolic control, not the reproductive function, could be recovered in the first 24 hours of refeeding. Malnutrition-induced hypoinsulinemia would be caused by an increase in a specific noradrenergic tone. 相似文献
10.
On strips of the isolated myocardium of right hearts auriculum of the 43 patients with ischemic illness of heart and 9 patients with heart diseases of various ethyology at statement venous canule during aorto-coronary shunting, estimated influence of adrenaline (10(-9)-10(-4) g/ml) on amplitude caused by electrostimulus (1H, 5ms, 25-30 V) contractions, and also inotropic and adrenomodulation activity of serum blood (in dilution 1 : 10000, 1: 1000, 1 : 500, 1: 100, 1 : 50, 1: 10 and 1 : 5) nonpregnant women. Direct dependence of amplitude of contraction on size of fraction of of blood emission on Teyholts is revealed. It means, that strips of right auriculum myocardium reflect contractility of a left ventriculum myocardium. Adrenaline in concentration 10(-7)-10(-6) g/ml dependent of dose raised amplitude of the caused contraction not influencing it in concentration of 10(-9) and 10(-8) g/ml (the constant of dissotiation has 2 x 10(-7) g/ml), that as a whole, speaks about decrease in efficiency of activation beta-AP. Blood Serum in dissolutions 1 : 10000-1 : 50 did not influence on amplitude of contraction, and in dissolutions 1 : 10 and 1 : 5 strengthened it, that speaks presence in blood the endogenous activator of myocyte contractility (EAMC). Serum showed beta-adrenomodulation activity that speaks presence in it endogenous sensitizer of beta-adrenoreceptors (ESBAR) and endogenous blocker of beta-adrenoreceptors (EBBAR). In particular, in experiences with adrenaline in subthreshold concentration (10(-8) g/ml) serum showed ESBAR-activity (in dissolutions 1 : 1000, 1 : 500, 1 : 100 and 1 : 50), and in experiences with adrenaline in as much as possible effective concentration (10(-6) g/ml) serum showed ESBAR-activity (in dissolutions 1 : 50 and 1 : 10) and EBBAR-activity (in dissolutions 1:500) Hence, containing in blood serum endogenous modulators of beta-adrenoreactivity - ESBAR and EBBAR can modulate efficiency of beta-adrenoreceptors activation of human cardiomyocytes. It speaks about perspectivity of application of ES BAR analogues in cardiology. 相似文献
11.
Gralak MA Piastowska AW Leontowicz H Leontowicz M Antczak A Kulasek GW Szara T Narojek T 《BioFactors (Oxford, England)》2004,22(1-4):25-28
Bone mineralization was studied in rats. Animals were divided into three feeding groups: LCP - diet with 13.5% crude protein in DM (5% of gluten, 10% of casein), HCP - diet with 21.2% CP in DM (8% of gluten, 10% of casein), and LSM - diet based on grain meals and meat-bone meal (21% CP in DM). After 28 days feeding, animals were euthanased by cervical dislocation and femur bones were collected, weighed and kept frozen until analyses. Diets with 21% protein (HCP, LSM) significantly increased weight of femur bones. Despite of the substantially higher ash level (7.1%) in the LSM diet than in the LCP diet (3.4%), rats of both groups had the similar bone concentration of Ca (15.7 +/- 1.1 vs. 17.4 +/- 1.1 g/kg) and Zn (178.7 +/- 7.9 vs. 173.0 +/- 8.5 mg/kg). However bone density in LSM rats was significantly higher than in LCP ones. Although rats fed HCP diet had intermediate bone density, the bone concentration of Ca (11.4 +/- 0.5 g/kg) and Zn (145.1 +/- 2.9 mg/kg) was significantly lower, than in animals fed LCP and LSM diets. This was related to the very wide protein/calcium (37:1 g/g) and protein/zinc (5.3:1 g/mg) ratios in HCP diet. Those ratios were narrowest in the LSM diet: 16.2:1 (CP/Ca) and 2.6:1 (CP/Zn). It can be conluded that protein/mineral ratio in a diet is a very important factor in bone development, besides dietary protein and ash contents itselves. 相似文献
12.
目的:研究海南汉族人群MICB等位基因的多态性与乳腺癌易感性之间的关联性。方法:采用PCRSSP(PCR sequence-specific primers)和PCR-SBT(PCR sequence-based typing)方法对样本MICB等位基因的多态性进行检测。结果:乳腺癌患者中检出14种MICB等位基因;和对照组相比较,MICB*002和MICB*014等位基因在乳腺癌患者组分布频率较少,MICB*002和MICB*014等位基因可能对乳腺癌不易感(MICB*002:OR=0.31,95%CI:0.19-0.51,Pc0.05;MICB*014:OR=0.32,95%CI:0.17-0.60,Pc0.05)。MICB*016和MICB*003等位基因在乳腺癌患者组分布较多;MICB*016和MICB*003等位基因可能对乳腺癌易感(MICB*016:OR=10.68,95%CI:2.52-45.28,Pc0.05;MICB*003:OR=3.57,95%CI:1.34-9.49,Pc0.05);MICB*002/002和MICB*014/014基因型可能对乳腺癌不易感(MICB*002/002:OR=0.12,95%CI:0.04-0.36,Pc0.05;MICB*014/014:OR=0.30,95%CI:0.10-0.89,Pc0.05)。结论:MICB等位基因的多态性与乳腺癌的易感性之间存在关联性。 相似文献
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The effects of abdominal vagotomy (AVGT) on ovarian function were studied in cyclic hamsters. AVGT significantly decreased the number of ova shed (AVGT: 10.5 +/- 1.5 ova/hamster, sham: 15.8 +/- 0.7 ova/hamster; P less than 0.05) and serum progesterone levels (AVGT: 2.1 +/- 0.3 ng/ml, sham: 3.9 +/- 0.7 ng/ml; P less than 0.05) on the morning of estrus. However, progesterone concentrations in the corpora lutea and non-luteal ovary on estrus in the AVGT and sham groups were similar. The serum estradiol levels in both groups on proestrus increased from 0900 h (AVGT: 75 +/- 10 pg/ml, sham: 72 +/- 6 pg/ml) to 1500 h (AVGT: 204 +/- 27 pg/ml, sham: 196 +/- 35 pg/ml) but there was no significant difference between the two groups. Partial degranulation of ovarian mast cells was not increased in the AVGT group. Also, vasoactive intestinal peptide (VIP) content in the ovary was not increased by AVGT at 0900 h on proestrus (AVGT: 60.1 +/- 16.8 pg/ovary, sham: 37.2 +/- 14.3 pg/ovary). These results indicated that AVGT interferes with normal ovulation and results in an increase in the number of atretic follicles, but that these effects by AVGT seemed not to be mediated through ovarian mast cells and VIP. 相似文献
14.
To determine if acute exposure to ozone can cause changes in the production of cyclooxygenase metabolites of arachidonic acid (AA) in the lung which are associated with changes in lung mechanics, we exposed mongrel dogs to 0.5 ppm ozone for two hours. We measured pulmonary resistance (RL) and dynamic compliance (Cdyn) and obtained methacholine dose response curves and bronchoalveolar lavagate (BAL) before and after the exposures. We calculated the provocative dose of methacholine necessary to increase RL 50% (PD50) and analyzed the BAL for four cyclooxygenase metabolites of AA: a stable hydrolysis product of prostacyclin, 6-keto-prostaglandin F1 alpha (6-keto-PgF1 alpha); prostaglandin E2 (PgE2); a stable hydrolysis product of thromboxane A2, thromboxane B2 (TxB2); and prostaglandin F2 alpha (PgF2 alpha). Following ozone exposure, RL increased from 4.75 +/- 1.06 to 6.08 +/- 1.3 cm H2O/L/sec (SEM) (p less than 0.05), Cdyn decreased from 0.0348 +/- 0.0109 TO .0217 +/- .0101 L/cm H2O (p less than 0.05), and PD50 decreased from 4.32 +/- 2.41 to 0.81 +/- 0.49 mg/cc (p less than 0.05). The baseline metabolite levels were as follows: 6-keto PgF1 alpha: 96.1 +/- 28.8 pg/ml; PgE2: 395.8 +/- 67.1 pg/ml; TxB2: 48.5 +/- 11.1 pg/ml; PgF2 alpha: 101.5 +/- 22.6 pg/ml. Ozone had no effect on any of these prostanoids. These studies quantify the magnitude of cyclooxygenase products of AA metabolism in BAL from dog lungs and demonstrate that changes in their levels are not prerequisites for ozone-induced changes in lung mechanics or airway reactivity. 相似文献
15.
Manuele MG Ferraro G Barreiro Arcos ML López P Cremaschi G Anesini C 《Life sciences》2006,79(21):2043-2048
Some coumarins possess enhancing effects on lymphocyte mitogen responsiveness. In this investigation, the activity of scopoletin, a coumarin that has been isolated from different plants and in this case specifically from T. cordata Mill., was evaluated. For this purpose, normal T lymphocytes and a hyperproliferative T lymphoma cell line were used. Scopoletin was found to exert a dual action on tumoral lymphocytes exhibiting both a cytostatic and a cytotoxic effect. These effects varied with the concentrations analysed and the time of cell incubation (EC(50): 251+/-15 microg/ml) and were associated to the induction of apoptosis. Scopoletin induced cell proliferation on normal T lymphocytes (Proliferation stimulation index: 1 microg/ml scopoletin: 1.26+/-0.1; 10 microg/ml scopoletin: 3+/-0.25; 100 microg/ml scopoletin: 1.86+/-0.08); this stimulatory action was found to be due to the interaction with kinase C (PKC) protein. These results indicate that scopoletin could be a potential antitumoral compound to be used for cancer treatment. 相似文献
16.
The effect of iron chlorosis on mineral, thylakoid lipids and fatty acids composition of field grown peach tree leaves was studied. Significant differences were found in iron extracted by using , -dipyridyl (active iron), total iron, P, K, Cu and the P/Fe and Fe/Mn ratios. The levels of total chlorophyll, total glycolipids and phospholipids were reduced under iron chlorosis. A slight iron deficiency does not modify the fatty acid composition of thylakoid membranes, while a strong deficiency changes the proportion of some fatty acids.Abbreviations Chl
chlorophyll
- DGDG
digalactosyldiglycerol
- MGDG
mono-galactosyldiglycerol
- PC
phosphatidycholine
- PE
phophatidylethanolamine
- PG
phophatidylglycerol
- TLC
thin layer chromatography
- 16:0
palmitic acid
- 16:1
palmitoleic acid
- 16:lt
trans-hexadecenoic
- 18:0
steric acid
- 18:1
oleic acid
- 18:2
linoleic acid
- 18:3
linolenic acid 相似文献
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Micropipette pressurization of giant bilayer vesicles was used to measure both elastic bending k(c) and area stretch K(A) moduli of fluid-phase phosphatidylcholine (PC) membranes. Twelve diacyl PCs were chosen: eight with two 18 carbon chains and degrees of unsaturation from one double bond (C18:1/0, C18:0/1) to six double bonds per lipid (diC18:3), two with short saturated carbon chains (diC13:0, diC14:0), and two with long unsaturated carbon chains (diC20:4, diC22:1). Bending moduli were derived from measurements of apparent expansion in vesicle surface area under very low tensions (0.001-0.5 mN/m), which is dominated by smoothing of thermal bending undulations. Area stretch moduli were obtained from measurements of vesicle surface expansion under high tensions (>0.5 mN/m), which involve an increase in area per molecule and a small-but important-contribution from smoothing of residual thermal undulations. The direct stretch moduli varied little (< +/-10%) with either chain unsaturation or length about a mean of 243 mN/m. On the other hand, the bending moduli of saturated/monounsaturated chain PCs increased progressively with chain length from 0.56 x 10(-19) J for diC13:0 to 1.2 x 10(-19) J for diC22:1. However, quite unexpectedly for longer chains, the bending moduli dropped precipitously to approximately 0.4 x 10(-19) J when two or more cis double bonds were present in a chain (C18:0/2, diC18:2, diC18:3, diC20:4). Given nearly constant area stretch moduli, the variations in bending rigidity with chain length and polyunsaturation implied significant variations in thickness. To test this hypothesis, peak-to-peak headgroup thicknesses h(pp) of bilayers were obtained from x-ray diffraction of multibilayer arrays at controlled relative humidities. For saturated/monounsaturated chain bilayers, the distances h(pp) increased smoothly from diC13:0 to diC22:1 as expected. Moreover, the distances and elastic properties correlated well with a polymer brush model of the bilayer that specifies that the elastic ratio (k(c)/K(A))(1/2) = (h(pp) - h(o))/24, where h(o) approximately 1 nm accounts for separation of the headgroup peaks from the deformable hydrocarbon region. However, the elastic ratios and thicknesses for diC18:2, diC18:3, and diC20:4 fell into a distinct group below the correlation, which showed that poly-cis unsaturated chain bilayers are thinner and more flexible than saturated/monounsaturated chain bilayers. 相似文献
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19.
Contrasting effects of NO and peroxynitrites on HSP70 expression and apoptosis in human monocytes 总被引:4,自引:0,他引:4
Adrie C Richter C Bachelet M Banzet N François D Dinh-Xuan AT Dhainaut JF Polla BS Richard MJ 《American journal of physiology. Cell physiology》2000,279(2):C452-C460
The free radicals nitric oxide(·NO) and superoxide (O2·) react to formperoxynitrite (ONOO), a highly toxic oxidant species. Inthis study we investigated the respective effects of NO andONOO in monocytes from healthy human donors. Purifiedmonocytes were incubated for 6 or 16 h with a pure NO donor(S-nitroso-N-acetyl-DL-penicillamine, 0-2 mM), an ·NO/ONOO donor(3-morpholinosydnonimine chlorhydrate, 0-2 mM) with and withoutsuperoxide dismutase (200 IU/ml), or pure ONOO. Weprovide evidence that 3-morpholinosydnonimine chlorhydrate alonerepresents a strong stress to human monocytes leading to adose-dependent increase in heat shock protein-70 (HSP70) expression, mitochondrial membrane depolarization, and cell death by apoptosis andnecrosis. These phenomena were abolished by superoxide dismutase, suggesting that ONOO, but not ·NO, was responsible forthe observed effects. This observation was further strengthened by theabsence of a stress response in cells exposed toS-nitroso-N-acetyl-DL-penicillamine. Conversely, exposure of cells to ONOO alone also inducedmitochondrial membrane depolarization and cell death by apoptosis andnecrosis. Thus ONOO formation may well explain the toxiceffect generally attributed to ·NO. 相似文献
20.
Anesthetics operate by different mechanisms and are often used to perform urodynamics in animals. The objective of this study was to compare the effects of ketamine/xylazine and urethane anesthetics on filling, voiding, and leak point pressure (LPP) in female rats. Nineteen rats underwent awake cystometry 2 days after suprapubic bladder catheter implantation. Bladders were filled with saline (5 ml/hr), while bladder pressure was measured. Half the rats were then anesthetized with urethane i.p. and half were anesthetized with ketamine and xylazine i.p. (K/X). All rats then underwent cystometry and LPP testing under anesthesia. Spontaneous nonvoiding contractions were analyzed and capacity was determined by voiding or leakage. Capacity was significantly higher in awake rats (0.55 +/- 0.06 ml) than with either K/X (0.21 +/- 0.06 ml) or urethane (0.30 +/- 0.05 ml). The pressure just prior to voiding in awake cystometry (15.6 +/- 1.7 cm H2O) was not significantly different from that with either anesthetic (K/X: 10.1 +/- 1.0 cm H2O; urethane: 13.3 +/- 2.0 cm H2O). Spontaneous nonvoiding contractions occurred in 4 rats with urethane and 3 rats with K/X. The volume at which the first contraction occurred was significantly lower with K/X (0.05 +/- 0.02 ml) than urethane (0.19 +/- 0.04 ml). There was no significant difference in the frequency of spontaneous nonvoiding contractions between K/X (4.58 +/- 0.30/min) and urethane (5.16 +/- 2.66/min), nor was there a difference in LPP between anesthetics (K/X: 40.4 +/- 2.4 cm H2O; urethane: 36.2 +/- 3.9 cm H2O). The results suggest that urethane is preferable to K/X for anesthetized cystometry studies since it more closely simulates normal physiological responses. 相似文献