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1.
Yoshiji Ohta Koji Yashiro Shingo Kaida Yoichiro Imai Koji Ohashi Akira Kitagawa 《Cell biochemistry and function》2013,31(3):254-262
We examined whether water‐immersion restraint stress (WIRS) disrupts nonenzymatic antioxidant defense systems through ascorbic acid depletion in the adrenal gland of rats. Rats were exposed to WIRS for 0.5, 1.5, 3 or 6 h. WIRS increased serum adrenocorticotropic hormone, corticosterone and glucose concentrations and adrenal corticosterone content at each time point. WIRS increased adrenal lipid peroxide content at 3 and 6 h, and the increase was twofold higher than the unstressed level at 6 h. WIRS decreased adrenal ascorbic acid content at each time point, and the decrease reached one‐third of the unstressed level at 6 h. WIRS increased adrenal reduced glutathione content at 0.5 and 6 h but reduced that content to half of the unstressed level at 6 h. WIRS increased adrenal α‐tocopherol content at 1.5 h but returned that content to the unstressed level thereafter. When rats with 6 h of WIRS was orally preadministered with l ‐ascorbic acid (250 mg/kg), WIRS‐induced changes in adrenal lipid peroxide, ascorbic acid and reduced glutathione contents were attenuated without any change in stress response. These results indicate that WIRS disrupts nonenzymatic antioxidant defense systems through rapid and continuous ascorbic acid depletion in the adrenal gland of rats. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
2.
Ohta Y Chiba S Tada M Imai Y Kitagawa A 《Redox report : communications in free radical research》2007,12(3):139-147
We examined how oxidative stress and cell damage develop in the liver of rats subjected to water-immersion stress (WIRS). In rats subjected to WIRS for 1.5, 3 or 6 h, serum alanine aminotransferase and aspartate aminotransferase activities increased time-dependently. In the liver tissue, vacuolization and apoptosis occurred at 1.5 h of WIRS and vacuolization further developed without further appearance of apoptosis at 3 h or 6 h. Serum lipid peroxide (LPO) and NOx (nitrite/nitrate) concentrations increased at 3 h of WIRS and these increases were enhanced at 6 h. In liver tissue, increases in LPO and NOx concentrations and myeloperoxidase activity and decreases in ascorbic acid and reduced glutathione concentrations and superoxide dismutase activity occurred at 3 h of WIRS and these changes were enhanced at 6 h, although vitamin E concentration and xanthine oxidase activity were unchanged. These results indicate that oxidative stress in the liver of rats with WIRS develops after the appearance of cell damage in the tissue, and suggests that oxidative stress is caused through disruption of the antioxidant defense system and increases in NO generation and neutrophil infiltration in the liver, which may contribute to the progression of cell damage in the tissue. 相似文献
3.
Protective effects of ascorbic acid, Dl-α-tocopherol acetate, and sodium selenate on ethanol-induced gastric mucosal injury of rats 总被引:2,自引:0,他引:2
Ozdil S Yanardag R Koyuturk M Bolkent S Arbak S 《Biological trace element research》2004,99(1-3):173-189
In this study, the effect of ascorbic acid (vitamin C), Dl-α-tocopherol acetate (vitamin E), and sodium selenate (selenium) on ethanol-induced gastric mucosal injury in rats was investigated
morphologically and biochemically. The gastric mucosal injury was produced by administration of 1 mL of absolute ethanol to
each rat. Animals received vitamin C (250 mg/kg), vitamin E (250 mg/kg), and selenium (0.5 mg/kg) for 3 d 1 h prior to the
administration of absolute ethanol. In gastric mucosa of rats given ethanol according to control groups, neuronal nitric oxide
expression decreased. This immunoreactivity was much lower in the group given ethanol+vitamin C+vitamin E+selenium than the
control group and the ethanol-induced group. Scanning electron microscopic evaluation of the ethanol-induced group, when compared
to control groups, revealed degenerative changes in gastric mucosa, whereas a good arrangement in surface topography of gastric
mucosa in the group given ethanol + vitamin C+vitamin E + selenium was observed. In the group administered ethanol, a reduction
of the stomach glutathione (GSH) and serum total protein levels and increases in serum sialic acid, triglycerides, and stomach
lipid peroxidation (LPO) levels were observed. Vitamin C+vitamin E+Se administration to alcohol-treated rats significantly
increased the serum total protein, triglyceride levels, and stomach GSH levels and significantly lowered the levels of serum
sialic acid and stomach LPO compared to untreated alcohol-supplemented rats. As a result of these findings, we can say that
the combination of vitamin C, vitamin E, and selenium has a protective effect on ethanol-induced gastric mucosal injury of
rats. 相似文献
4.
Intrathymic and intrasplenic oxidative stress mediates thymocyte and splenocyte damage in acutely exercised mice. 总被引:5,自引:0,他引:5
Reactive oxygen species may contribute to apoptosis in lymphoid tissues observed after exercise. Thymic and splenic tissues excised from control mice (C) or mice immediately after (t0) or 24 h after (t24) a run to exhaustion (RTE) were assayed for biochemical indexes of oxidative stress [thymic and splenic membrane lipid peroxides, superoxide dismutase, catalase, plasma uric acid (UA), and ascorbic acid (AA)]. There were significant increases in membrane lipid peroxides in thymus (P < 0.001) and spleen (P < 0.001) in acutely exercised mice relative to controls (thymus: C = 2.74 +/- 0.80 microM; t0 = 7.45 +/- 0.48 microM; t24 = 9.44 +/-1.41 microM; spleen: C = 0.48 +/- 0.22 microM; t0 = 1.78 +/- 0.28 microM; t24 = 2. 81 +/- 0.34 microM). The thymic and splenic tissue antioxidant enzymes concentrations of superoxide dismutase and catalase were significantly lower in samples collected at t0 relative to C and t24 mice (P < 0.001). Plasma UA and AA levels were used to assess the impact of the RTE on the peripheral antioxidant pool. There was no significant change in UA levels and a significant reduction in plasma AA concentrations (P < 0.001); the reduction in plasma AA occurred at t24 (6.53 +/- 1.64 microM) relative to t0 (13.11 +/- 0. 71 microM) and C (13.26 +/- 1.2 microM). These results suggest that oxidative damage occurs in lymphoid tissues after RTE exercise and that such damage may contribute to lymphocyte damage observed after acute exercise. 相似文献
5.
Onyema OO Farombi EO Emerole GO Ukoha AI Onyeze GO 《Indian journal of biochemistry & biophysics》2006,43(1):20-24
Monosodium glutamate (MSG), administered to rats (by gavage) at a dose of 0.6 mg/g body weight for 10 days, significantly (P<0.05) induced lipid peroxidation (LPO), decreased reduced glutathione (GSH) level and increased the activities of glutathione-s-transferase (GST), catalase and superoxide dismutase (SOD) in the liver of the animals; these were observed 24 hr after 10 days of administration. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma glutamyl transferase (GGT) were also significantly increased in the serum, on MSG administration. Vitamin E (0.2 mg/g body wt) co-administered with MSG, significantly reduced the LPO, increased the GSH level and decreased the hepatic activities of GST, catalase and SOD. The activities of ALT, AST and GGT in the serum were also significantly reduced. The results showed that MSG at a dose of 0.6 mg/g body wt induced the oxidative stress and hepatotoxicity in rats and vitamin E ameliorated MSG-induced oxidative stress and hepatotoxicity. 相似文献
6.
《Free radical research》2013,47(6):485-493
Forty-five mutant male ODs rats, unable to synthesize ascorbic acid, were fed nine diets containing 5, 50 or 250 mg of vitamin E/kg diet and 150,300 or 900 mg of vitamin C/kg diet for 21 days. The concentrations of vitamins C and E increased in liver and plasma in relation to the level of these vitamins in the diet. Vitamin C dietary supplementation increased the plasma vitamin E content at low levels of vitamin E intake, supporting the concept of an in vivo synergism between both antioxidant vitamins. Vitamin C, at the dietary levels studied, did not affect the lipid peroxidation. Vitamin E decreased liver and plasma endogenous levels of thiobarbituric acid-reactive substances and liver sensitivity to non-enzymatic lipid peroxidation. This was confirmed by a highly specific assay of lipid hydroperoxides using high performance liquid chromatography with chemiluminescence detection. The hepatic concentration of both phosphatidylcholine and phosphatidylethanolamine hydroperoxides decreased as the vitamin E content of the diet increased. The results show for the first time the capacity of vitamin E to protect against peroxidation of major phospho-lipids in vivo under basal unstressed conditions. 相似文献
7.
Oxidative stress, associated with a high production of reactive oxygen species (ROS) by immune cells, is involved in the endotoxic shock caused by endotoxin. This oxidative stress is linked to the inability of the immune cells to maintain adequate levels of antioxidants with free radical-scavenging action. Glutathione (GSH) and ascorbic acid (AA) are intracellular and extracellular antioxidants (ROS scavengers) that improve the leukocyte functions. Therefore, in the present work we have determined the reduced GSH and AA content in axillary nodes, spleen, thymus and peritoneal mononuclear leukocytes from BALB/c mice subjected to lethal endotoxic shock produced by intraperitoneal injection of E. coli lipopolysaccharide (LPS, 100 mg/kg), at several times (0, 2, 4, 12 and 24 h) after LPS injection. Endotoxic shock decreased the levels of AA in the leukocytes from the three organs as well as the levels of GSH in axillary nodes and spleen cells while it increased the GSH levels in thymus and peritoneum. These results are in agreement with the oxidative stress and the altered function previously observed in those leukocytes, and they suggest that antioxidant administration may be useful for the treatment of endotoxic shock and other oxidative stress situations with altered immunological responses. 相似文献
8.
Lipid peroxidation in blood of vitamin B6 deficient rats was significantly increased when compared to pair-fed controls. The observed increased lipid peroxidation in vitamin B6 deficiency was correlated with high levels of lipids, metal ions and low levels of antioxidants, alpha-tocopherol, ascorbic acid and reduced GSH. Supplementation of methionine or vitamin E along with the vitamin B6 deficient diet restored the levels of antioxidants to near normal and also protected against oxidative stress. However plasma TBARS level as well as total lipids were still elevated in M-B6 diet fed rats and normalized in E-B6-d rats. 相似文献
9.
胸腺对雌性大鼠肝脏抗氧化功能的影响及其与细胞免疫、性激素水平的关系 总被引:2,自引:0,他引:2
雌性成年大鼠切除胸腺后,其肝脏脂质过氧化产物丙二醛增多,还原型谷胱甘肽(GSH)含量减少,微粒体和线粒体膜流动性降低。隔日1次皮下注射自猪胸腺提取的胸腺因子D(TFD)2mg/kg共3月,可逆转去胸腺大鼠上述指标的变化。为了探讨胸腺影响肝脏抗氧化功能的中间途径,还测定了脾T淋巴细胞增殖反应及血浆性激素水平。结果表明,去胸腺大鼠脾脏T淋巴细胞增殖反应减弱、血浆雌二醇/睾酮比值下降;给予TFD可逆转其变化。实验结果提示,胸腺对大鼠肝脏抗氧化功能的影响可能与胸腺-内分泌-免疫网络有关。 相似文献
10.
The aim of this work was to determine the protective effects of intraperitoneally administered vitamin E and selenium (as
Na2SeO3, Se) on the lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and vitamin E levels, glutathione peroxidase
(GSH-Px), reduced glutathione (GSH) activities in the plasma, red blood cell (RBC), liver, and muscle of rats with streptozotocin-induced
diabetes. Fifty adult male Wistar rats were used and all rats were randomly divided into five groups. The first group was
used as a control and the second group as a diabetic control. A placebo was given to first and second groups by injection.
The third group was intraperitoneally administered with vitamin E (20 mg over 24 h), the fourth group with Se (0.3 mg over
24 h), and the fifth group with vitamin E and Se combination (COM) (20 mg vitamin E + 0.3 mg Se over 24 h). This administration
was done for 25 days and the TBARS, vitamin E, GSH-Px, GSH levels in the plasma, RBC, liver, and muscle samples were determined.
The vitamin E level in the plasma and liver was significantly (p < 0.05) higher in the control than in the diabetic control group. Also, the TBARS levels in the RBC, liver, and muscle were
significantly (p < 0.05) lower in the control than in the diabetic control group. However, GSH-Px and GSH activities in RBC, liver, and muscle
were not statistically different between the control and the diabetic control groups. The vitamin E levels in plasma and liver
(p < 0.01 and p < 0.001) and GSH-Px activities (p < 0.01, p < 0.001) in RBC were significantly higher in vitamin E, Se, and COM groups than in both control and diabetic control groups.
However, the TBARS levels of RBC, muscle, and liver in vitamin E and Se administered groups were significantly (p < 0.05-p < 0.001, respectively) decreased. These results indicate that intraperitoneally administered vitamin E and Se have significant
protective effects on the blood, liver, and muscle against oxidative damage of diabetes.
The abstract of this study was presented in Physiological Research
48(Suppl. 1), S99 (1999). 相似文献
11.
The present study investigates the antioxidative effects of vitamin E and curcumin against l-thyroxine (T4)-induced oxidative stress in renal cortex of adult male rats. Rats were made hyperthyroid by administration of l-thyroxine (0.0012%) in their drinking water for 30 days. Vitamin E (200 mg/kg body weight/day) and curcumin (30 mg/kg body
weight/day) were supplemented singly or in combination orally for 30 days along with l-thyroxine treatment. The elevated level of oxidative stress parameters (lipid peroxidation and protein carbonylation) and
decline level of small antioxidant molecules (reduced glutathione and ascorbic acid) in renal cortex of T4-treated rats were restored back by supplementation of vitamin E or/and curcumin. Increased superoxide dismutase and catalase
activities in kidney cortex of T4-treated rats were ameliorated in response to vitamin E or/and curcumin treatment. The elevated translated product of Cu/Zn-SOD,
Mn-SOD and catalase in T4-treated rats were differentially reduced by the administration of vitamin E and curcumin independently or in combination.
Cu/Zn-SOD expression was ameliorated by both vitamin E and curcumin independently or in combination, whereas Mn-SOD expression
was ameliorated by the supplementation of vitamin E or curcumin independently. However, the expression of catalase was alleviated
by only supplementation of vitamin E to T4-treated rats. The results suggest that both vitamin E and curcumin may play an important role in protecting T4-induced oxidative stress in rat renal cortex by differentially modulating the activities of antioxidant enzymes and oxidative
stress parameters. 相似文献
12.
Sinan Ince Ismail Kucukkurt Ibrahim Hakki Cigerci A. Fatih Fidan Abdullah Eryavuz 《Journal of trace elements in medicine and biology》2010,24(3):161-164
The aims of this study were to clarify the effects of high dietary supplementation with boric acid and borax, called boron (B) compounds, on lipid peroxidation (LPO), antioxidant activity, some vitamin levels, and DNA damage in rats. Thirty Sprague Dawley male rats were divided into three equal groups: the animals in the first group (control) were fed with a standard rodent diet containing 6.4 mg B/kg, and the animals in the experimental group were fed with a standard rodent diet added with a supra-nutritional amount of boric acid and borax (100 mg B/kg) throughout the experimental period of 28 days. The B compounds decreased malondialdehyde (MDA), DNA damage, the protein carbonyl content (PCO) level in blood, and glutathione (GSH) concentration in the liver, Cu–Zn superoxide dismutase (SOD), and catalase (CAT) activity in the kidney. The B compounds increased GSH concentration in blood and the vitamin C level in plasma. Consequently, our results demonstrate that B supplementation (100 mg/kg) in diet decreases LPO, and enhances the antioxidant defense mechanism and vitamin status. There are no differences in oxidant/antioxidant balance and biochemical parameters except for serum vitamin A and liver GSH concentration, between the boron compounds used in this study. 相似文献
13.
Oxidative stress is considered to be the main cause of diabetic complications. In the current study, we investigated the effect
of selenium–vitamin E combination and melatonin on lipid peroxidation (LPO) and scavenging enzyme activity in the blood of
streptozocin (STZ)-induced diabetic pregnant rats. Forty female Wistar rats were randomly divided into five groups. The first
and second groups were used as the non-pregnant control and pregnant control groups, respectively. The third group was the
pregnant diabetic group. Vitamin E plus selenium and melatonin were administered to the diabetic pregnant rats consisting
fourth and fifth groups, respectively. Diabetes was induced on day 0 of the study by STZ. Blood samples were taken from all
animals on the 20th day of pregnancy. LPO level was higher in diabetic pregnant rats than in control, although superoxide
dismutase, catalase, and glutathione peroxidase activities were lower in diabetic pregnant animals than in control. LPO levels
were lower both in the two treatment groups than in the diabetic pregnant rats, whereas selenium–vitamin E combination and
melatonin caused a significant increase in the activities of these antioxidant enzymes (p < 0.01). In conclusion, vitamin E plus selenium seems to be a more potent antioxidant compared to melatonin in diabetic pregnant
rats. Melatonin did not significantly affect the elevated glucose concentration of diabetic pregnant treated with melatonin
group. Vitamin E plus selenium may play a role in preventing diabetes-related diseases of pregnant subjects. 相似文献
14.
El-Sokkary GH 《Cell proliferation》2008,41(1):168-176
Abstract. Objective : Oxidative stress is a likely molecular mechanism in long-term diazepam administration. The benefits of antioxidants (melatonin and vitamin C) against diazepam-induced cell proliferation, DNA synthesis and oxidative damage were investigated in this study. Materials & methods : Four equal-sized groups of male rats [control, diazepam (3 mg/kg), diazepam plus melatonin (5 mg/kg) and diazepam plus vitamin C (50 mg/kg)] were used. Levels of lipid peroxides (LPO), superoxide dismutase (SOD) activity and glutathione (GSH) concentration were measured in tissue homogenates. Cell proliferation and rate of DNA synthesis were detected by autoradiography. Results : Results documented increased labelling index, 3 H-thymidine incorporation (DNA synthesis), LPO plus decrease in GSH levels and SOD activity in livers of diazepam-administered rats versus those of controls. When melatonin and vitamin C were given to diazepam-administered rats, they almost attenuated the increase of labelling index, DNA synthesis and LPO, and restored the levels of GSH and SOD activity. Conclusion : These results suggest long-term hazard in use of drugs such as diazepam; they may be toxic and damage terminates in complex liver damage. Furthermore, melatonin and vitamin C may be useful in combating free radical-induced liver injury resulting from hazard and/or repeated diazepam administration. 相似文献
15.
Protective effect of alpha-tocopherol on oxidative stress in experimental pulmonary fibrosis in rats
The study was undertaken to investigate the influence of alpha-tocopherol (vitamin E) on malondialdehyde (MDA) and glutathione (GSH) levels and catalase (CAT) activity in lung of rats with bleomycin-induced pulmonary fibrosis (PF). Fourteen Wistar-albino rats were randomly divided into two groups of seven animals each. The first group was treated intra-tracheally with bleomycin hydrochloride (BM group); the second group was also instilled with BM but received injections of alpha-tocopherol twice a week (BM + E group). The third group was treated in the same manner with saline solution only, acting as controls (C). There were decreases in GSH level and CAT activity while an increase in MDA level in BM group was found compared to the control group (p < 0.05). Vitamin E had a regulator effect on these parameters. After administration of alpha-tocopherol, the increase in GSH level and CAT activity and the decrease in MDA level were seen in BM + E group compared to BM group (p < 0.05). Distinct histopathological changes were found in the BM group compared to the untreated rats. Less severe fibrotic lesions were also observed in the BM + E group. The results show that vitamin E is effective on the prevention of BM-induced PF, as indicated by differences in the lung levels of oxidants and antioxidants. 相似文献
16.
Present study examines effects of curcumin and vitamin E on oxidative stress parameters, antioxidant defence enzymes and oxidized (GSSG) and reduced glutathione (GSH) levels in testis of L-thyroxine (T4)-induced hyperthyroid rats. The oxidative stress in T4-treated rat testis was evident from elevation in oxidative stress parameters such as lipid peroxide and protein carbonyl contents, decrease in superoxide dismutase (SOD) and catalase (CAT) activities and increase in glutathione peroxidase (GPx) activity. This is accompanied with decrease in number and mortality of epididymal sperms. When the T4-treated rats were fed with vitamin E and/or curcumin, the lipid peroxide and protein carbonyl contents in crude homogenates of testes decreased to normal level. Treatment of curcumin and/or vitamin E to T4-treated rats resulted in elevation of SOD level in postmitochondrial fraction (PMF) and mitochondrial fraction (MF) and CAT in PMF, with decreased GPx activity in MF. However, curcumin or vitamin E was unable to change GPx activity alone but in together they elevated the GPx in PMF of T4-treated rat testis. Both the antioxidants are incapable of producing significant changes in GSH:GSSG ratio of PMF of T4-treated rats. In MF, GSH:GSSG ratio elevated and decreased respectively by curcumin and vitamin E treatments to T4-treated rats, however, in together these antioxidants caused an elevated GSH:GSSG ratio with a value less than when vitamin E given alone to T4-treated rats. Vitamin E not the curcumin elevates total sperm count and percentage of live sperm impaired by hyperthyroid state. In summary, both vitamin E and curcumin are efficient in protecting testis from oxidative stress generated by T4 mainly in restoring antioxidant enzymes to the level of euthyroid animals up to some extent but vitamin E is more efficient than curcumin. 相似文献
17.
《Redox report : communications in free radical research》2013,18(5):229-235
AbstractThe antioxidant effect of the ethanolic extract of Hemidesmus indicus R.Br. root (EHI), an indigenous Ayurvedic medicinal plant in India, was studied in rats with ethanol-induced nephrotoxicity. Administering 5 g/kg body weight/day of ethanol for 60 days to male Wistar rats resulted in significantly elevated levels of serum urea, creatinine and uric acid as well as kidney thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH) and conjugated dienes (CD) as compared to those of the experimental control rats. Decreased levels of kidney superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), vitamin C and vitamin E were also observed on alcohol administration as compared with those of the experimental control rats. EHI was administered at a dose of 500 mg/kg body weight/day for the last 30 days of the experiment to rats with ethanol-induced kidney injury, which significantly decreased the levels of serum urea, uric acid and creatinine as well as kidney TBARS, LOOH and CD and significantly elevated the activities of SOD, CAT, GPx, GSH, vitamin C and vitamin E in kidney as compared to that of untreated ethanol-administered rats. Histopathological observations also correlated with the biochemical parameters. Thus, the data indicate that treatment with EHI offers protection against free radical-mediated oxidative stress in kidney of animals with ethanol-induced nephtrotoxicity. 相似文献
18.
Control of wild carrot somatic embryo development by antioxidants : a probable mode of action of 2,4-dichlorophenoxyacetic Acid 总被引:1,自引:0,他引:1
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As we previously reported for glutathione (GSH), both ascorbic acid (AA) and vitamin E were observed to suppress wild carrot (Daucus carota L.) somatic embryogenesis with little concomitant effect on biomass. Endogenous concentrations of AA were lower during embryo development than during cell proliferation, exhibiting a temporal pattern nearly identical to that of GSH. GSSG (oxidized GSH) reductase was found to be considerably more active in proliferating than in developing cultures, whereas no difference was evident in the case of dehydroascorbate (DHA) reductase. Both GSH and AA concentrations in these cells are governed by 2,4-D. These results show that redox status is a strong determinant of proliferative versus developmental growth and indicate that the mode of action of 2,4-D in this system may be explained at least in part by its influence on endogenous antioxidant levels. 相似文献
19.
Erythrocyte osmotic fragility (O.F.), acetylcholinesterase (AChE) activity,and the level of malonyl dialdehyde (MDA) of control, mefenamic acid treated, and mefenamic acid with vitamin E treated rats were investigated. Administration of mefenamic acid to albino rats brought about a significant increase in the osmotic fragility of red cells and a significant (p<0.01) decrease in the activity of AChE. We have also observed increased red cell level of MDA and decreased cholesterol (Chl), hemoglobin (Hb), and reduced glutathione (GSH) content. Supplementation of vitamin E to the mefenamic acid treated rats restored the O.F., AChE activity, level of MDA, and Chl, Hb, and GSH content almost to normal. These observations suggest that mefenamic acid causes functional impairment of red cell membrane, while vitamin E shows its protective role in maintaining normal red cell functions. 相似文献
20.
W C Wise 《Journal of cellular physiology》1978,97(2):161-167
We have examined the transport of amino acids by the sodium-dependent "A" and "ASC" system in thymic- and splenic-derived lymphocytes from the Long-Evans rat. Lymphocytes derived from the thymus transport amino acids by both the "A" and "ASC" systems, whereas lymphocytes from the spleen transport amino acids by the "ASC" system only. Thymic lymphocytes are capable of establishing a steady state distribution ratio of 7.9 for 2-aminoisobutyric acid, but splenic lymphocytes can attain only 3.5. The steady state distribution ratio of alanine was the same in both cell types. Sodium-independent transport is also different in splenic and thymic lymphocytes. But both cells move amino acids by a Na+-independent system for mediated exchange-diffusion. The studies show that lymphocytes derived from the spleen and thymus transport amino acids differently, and that the "T" lymphocytes from the spleen have membrane transport systems different from "T" lymphocytes from the thymus. 相似文献