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Shima Sadat Beheshti Rooy Ghasem Hosseini Salekdeh Mehdi Ghabooli Mansour Gholami Rouhollah Karimi 《Acta Physiologiae Plantarum》2017,39(12):264
In this study the cold tolerance potential of three Vitis vinifera cultivars including ‘Red Sultana’, ‘White Sultana,’ and ‘Flame Seedless’ was evaluated under greenhouse condition. After 15 leaves stage in average, the grapevine plants were subjected to cold stress regimes (4, 0 and ? 4 °C) and compared with control plants (24 °C). A clear increase in leaf electrolyte leakage (EL), thiobarbituric acid reactive substances (TBARS), and H2O2 concentrations was observed with decreasing temperature from 4 to ? 4 °C in all grapevine cultivars. Chilled plants showed marked increases in their abscisic acid (ABA), soluble sugars, and proline contents in compared to control vines. Upon exposure to cold stress, the EL, TBARS, H2O2, and relative water content of ‘Red Sultana’ were found to be lower compared to ‘White Sultana’ and ‘Flame Seedless’. Under 0 °C condition, ‘Red Sultana’ had the highest superoxide dismutase, guaiacol peroxidase and catalase activities, which was approximately twofold higher than those of all other cultivars. Soluble sugars such as glucose, fructose, and sucrose increased from 4 to ? 4 °C. These increments were higher in ‘Red Sultana’ compared to other cultivars which was concomitant with higher accumulation of endogenous ABA concentration in this cultivar. Higher accumulation of ABA and soluble sugars in ‘Red Sultana’ confirmed the key roles of these compounds in cold tolerance which could be applied as a cold tolerance marker for early selection of grapevine cultivars with the aim to establish vineyards in cold winter regions. 相似文献
58.
Samuel Dagogo‐Jack Indira Umamaheswaran Hasan Askari Gunjan Tykodi 《Obesity (Silver Spring, Md.)》2003,11(2):232-237
Objective: To examine the effects of graded doses of hydrocortisone (HC) on leptin secretion, and determine the effect of fasting. Research Methods and Procedures: This was a randomized, placebo‐controlled, crossover study, with a 1‐week “washout” period between interventions. Eight healthy subjects [age = 36 ± 2.3 years (±SE), body mass index = 31.5 ± 1.6 kg/m2] completed the dose‐response study in which an intravenous infusion of saline (placebo) or HC (30 or 100 mg) was administered for 24 hours. Four healthy subjects (age = 35.2 ± 3.0 years, body mass index = 27.1 ± 2.1 kg/m2) completed the fasting study, which entailed continuous infusion of saline, HC (300 mg/24 hours) in the fed state, or HC (300 mg/24 hours) with total caloric deprivation for 24 hours. Blood sampling was performed every 1 to 2 hours for measurement of leptin, cortisol, insulin, and glucose levels. Results: Peak hyperleptinemia occurred after 16 hours of HC infusion; peak/baseline leptin levels were 129% (placebo), 140% (30 mg of HC for 24 hours, p = 0.05), and 185% (100 mg of HC for 24 hours, p < 0.01). During infusion of HC (300 mg/24 hours or placebo), the peak/baseline plasma leptin levels were 16.1 ± 5.8/12.8 ± 5.9 ng/mL (placebo with food, 126%), 14.6 ± 6.0/12.5 ± 6.5 ng/mL (HC fasting, 117%), and 32.5 ± 12.5/12.0 ± 8.4 ng/mL (HC with food, 271%, p < 0.001). Discussion: Leptin secretory responses occur at physiological doses of HC, are obliterated by fasting, and thus may be of metabolic significance. 相似文献
59.
Radovan Murín Ghasem Mohammadi Dieter Leibfritz Bernd Hamprecht 《Neurochemical research》2009,34(7):1195-1203
The three essential amino acids, valine, leucine and isoleucine, constitute the group of branched-chain amino acids (BCAAs).
BCAAs are rapidly taken up into the brain parenchyma, where they serve several distinct functions including that as fuel material
in brain energy metabolism. As one function of astrocytes is considered the production of fuel molecules that support the
energy metabolism of adjacent neural cells in brain. Astroglia-rich primary cultures (APC) were shown to rapidly dispose of
the BCAAs, including valine, contained in the culture medium. While the metabolisms of leucine and isoleucine by APC have
already been studied in detail, some aspects of valine metabolism remained to be determined. Therefore, in the present study
an NMR analysis was performed to identify the 13C-labelled metabolites that are generated by APC during catabolism of [U-13C]valine and that are subsequently released into the incubation medium. The results presented show that APC (1) are potently
disposing of the valine contained in the incubation medium; (2) are capable of degrading valine to the tricarboxylic acid
(TCA) cycle member succinyl-CoA; and (3) release into the extracellular milieu valine catabolites and compounds generated
from them such as [U-13C]2-oxoisovalerate, [U-13C]3-hydroxyisobutyrate, [U-13C]2-methylmalonate, [U-13C]isobutyrate, and [U-13C]propionate as well as several TCA cycle-dependent metabolites including lactate.
This article is dedicated to Dr. George DeVries. 相似文献
60.
Golej DL Askari B Kramer F Barnhart S Vivekanandan-Giri A Pennathur S Bornfeldt KE 《Journal of lipid research》2011,52(4):782-793
Long-chain acyl-CoA synthetases (ACSLs) catalyze the thioesterification of long-chain FAs into their acyl-CoA derivatives. Purified ACSL4 is an arachidonic acid (20:4)-preferring ACSL isoform, and ACSL4 is therefore a probable regulator of lipid mediator production in intact cells. Eicosanoids play important roles in vascular homeostasis and disease, yet the role of ACSL4 in vascular cells is largely unknown. In the present study, the ACSL4 splice variant expressed in human arterial smooth muscle cells (SMCs) was identified as variant 1. To investigate the function of ACSL4 in SMCs, ACSL4 variant 1 was overexpressed, knocked-down by small interfering RNA, or its enzymatic activity acutely inhibited in these cells. Overexpression of ACSL4 resulted in a markedly increased synthesis of arachidonoyl-CoA, increased 20:4 incorporation into phosphatidylethanolamine, phosphatidylinositol, and triacylglycerol, and reduced cellular levels of unesterified 20:4. Accordingly, secretion of prostaglandin E2 (PGE2) was blunted in ACSL4-overexpressing SMCs compared with controls. Conversely, acute pharmacological inhibition of ACSL4 activity resulted in increased release of PGE2. However, long-term downregulation of ACSL4 resulted in markedly reduced PGE2 secretion. Thus, ACSL4 modulates PGE2 release from human SMCs. ACSL4 may regulate a number of processes dependent on the release of arachidonic acid-derived lipid mediators in the arterial wall. 相似文献