共查询到20条相似文献,搜索用时 15 毫秒
1.
Assessment of decalcifying protocols for detection of specific RNA by non-radioactive in situ hybridization in calcified tissues 总被引:6,自引:0,他引:6
Shibata Y Fujita S Takahashi H Yamaguchi A Koji T 《Histochemistry and cell biology》2000,113(3):153-159
For the best performance of in situ analysis of specific RNA expression in calcified tissues, it is necessary to choose an
appropriate protocol to decalcify the tissues. We evaluated the usefulness of various acid-based decalcifying reagents with
reference to 28 S rRNA staining by in situ hybridization using a thymine-thymine dimerized oligonucleotide probe. The reagents
evaluated were 10% nitric acid, 10% HCl, 5% formic acid, 5% trichloroacetic acid, Morse’s solution, Plank-Rychlo’s solution,
and K-CX solution, all of which are commonly used to decalcify tissues, and their effects on retention of morphology and RNA
were compared with EDTA-based solutions. When normal mouse mandible was used as a model tissue, well-preserved morphology
of ameloblasts was obtained from sections decalcified with Morse’s solution, 10% HCl, Plank-Rychlo’s solution, and K-CX solution,
and best retention of 28 S rRNA was obtained with 5% formic acid and Morse’s solution. We recommend Morse’s solution to decalcify
tissues to be processed for the rapid analysis of specific RNA expression. Indeed, we detected specific mRNAs strongly in
sections treated with Morse’s solution, and quantitative analysis showed that the ratio of signal intensities of 28 S rRNA
and the specific mRNAs correlated with each other depending on decalcifying solutions.
Accepted: 3 January 2000 相似文献
2.
The influence of dietary copper, iron, and ascorbic acid on iron utilization was examined in a 2×2×2 factorial experiment.
Male Sprague-Dawley weanling rats were fed copper-deficient (Cu-, 0.42 μg Cu/g) or copper-adequate (Cu+, 5.74 μg Cu/g) diets
that contained one of two levels of iron (38 or 191μg Fe/g) and ascorbic acid (0 or 1% of the diet). These eight diets were
fed for 20 d, and rats received an oral dose of 4 μCi iron-59 on d 15. Compared to Cu+ rats, the Cu− rats had 27% lower hemoglobin
levels with 45, 59, and 65% lower cytochrome c oxidase (CCO) activities in the liver, heart, and bone marrow, respectively
(p<0.0001). High dietary iron or ascorbic acid did not alter hemoglobin in Cu+ rats. However, hemoglobin was 23% lower in Cu−
rats fed the highest, rather than the lowest levels of iron and ascorbic acid. Liver CCO was decreased (p<0.02) in Cu− rats fed high iron. Among Cu− rats, ascorbic acid did not influence CCO but decreased hemoglobin by 17% (p<0.001), reduced the percentage of absorbed iron-59 in the erythrocytes by 91% (p<0.05) and depressed the percentage apparent absorption of iron (p<0.05). These results suggest that the effects of elevated dietary iron and ascorbic acid on iron utilization are influenced
by copper status. 相似文献
3.
Effects of various decalcification protocols on detection of DNA strand breaks by terminal dUTP nick end labelling 总被引:1,自引:0,他引:1
Yamamoto-Fukud T Shibata Y Hishikawa Y Shin M Yamaguchi A Kobayashi T Koji T 《The Histochemical journal》2000,32(11):697-702
To analyse DNA strand breaks by terminal deoxy(d)-UTP nick-end labelling (TUNEL) in calcified tissues including bones and teeth, it is important to decalcify the tissues first. However, the effects of decalcifying reagents on the integrity of DNA are largely unknown. In the present study, we evaluated the usefulness of various decalcifying reagents including 10% EDTA (pH 7.4), 5% trichloroacetic acid (TCA), 5% formic acid, 5% HCl, 10% nitric acid, Plank–Rychlo's solution, Morse's solution and K-CX solution in TUNEL staining. Mouse maxilla was selected as the experimental system. Apoptotic cells naturally occurring in the epithelium were analysed. Tissues were assessed by soft X-ray imaging to confirm complete decalcification. The time required for decalcification of the tissue was 7 days with 10% EDTA and 2 days with other decalcifiers. Decalcified tissues were stained with Methyl/Green–Pyronine Y or 4, 6-diamidino-2-phenylindole for assessment of DNA integrity. Nuclei of epithelial cells were strongly positive for both dyes after decalcification with 10% EDTA, 5% TCA, Morse's solution and 5% formic acid. The other reagents failed to retain DNA. Our results demonstrated good TUNEL staining of the maxilla treated with 10% EDTA or 5% TCA . Based on the required time for processing and the signal-noise ratio, we recommend 5% TCA as the decalcifying reagent to analyse for DNA strand breaks. 相似文献
4.
The mycelia of Aspergillus niger, cultivated in a medium containing 45 g l−1 maltose, 66 g l−1 yeast extract, and 5 g l−1 K2HPO4 at 30°C and 200 rpm, were used as a biocatalyst in the glucosylation of ascorbic acid. Free mycelia from 3-day-old culture,
when used in a 6-h reaction with maltose as the acyl donor, gave 16.07 g l−1 ascorbic acid glucoside corresponding to a volumetric productivity of 2.68 g l−1 h−1 and a conversion of 67%. Mycelia from 3-day-old cultures were entrapped in calcium alginate beads and used as a catalyst
in the glucosylation of ascorbic acid. An ascorbic acid-to-maltose molar ratio of 1:9 was found to be optimum, and the conversion
reached 75% after 12 h. The concentration of ascorbic acid glucoside produced at this molar ratio was 17.95 g l−1, and the productivity was 1.5 g l−1 h−1. The biocatalyst was repeatedly used in a fixed bed bioreactor for the synthesis of ascorbic acid glucoside and approximately
17 g l−1 of ascorbic acid glucoside corresponding to a volumetric productivity of 1.42 g l−1 h−1 was produced in each use. The conversion was retained at 70% in each use. The entrapped mycelia also exhibited exceptionally
high reusability and storage stability. The product was purified to 85% by anion exchange and gel permeation chromatography
with a final yield of 75%. 相似文献
5.
Malcolm R. Brown 《Journal of applied phycology》1995,7(5):495-500
Microalgae concentrates, prepared by centrifuging axenic (bacteria-free) cultures of Chaetoceros calcitrans (Paulsen) Takano, were processed and stored under different experimental conditions. The content of ascorbic acid was examined
in the concentrates, to assess potential changes in their nutritional properties. In algae pastes stored at 4 °C, it reduced
by 29% after 4 weeks storage. As most of the ascorbic acid was retained intracellularly (92%) after resuspension, most of
the cells had remained intact. In frozen and dried paste preparations, the losses of ascorbic acid ranged from minor (11%
after liquid nitrogen storage for 4 weeks) to major (≥94% after drying at 100 °C for 2 h or at 60 °C overnight). However,
most of the remaining ascorbic acid (>85%) in these preparations was rapidly leached from cells upon resuspension. Therefore,
pastes stored at 4 °C may have the best potential as an ‘off-the-shelf’ microalgal food product for mariculture. Pastes should
now be assessed in animal feeding trials, before being recommended for widespread use in the industry. 相似文献
6.
Summary A method for histochemical demonstration of hydrolytic and oxidative enzymes following decalcification was described in mature bone and tooth by neutral EDTA decalcifying solution.The decalcifying solution, 0.5 M EDTA tetrasodium salt was adjusted to neutral pH with 5 M citric acid, obtained the most sufficient results for demonstration of enzymes in decalcified tissue. The hard tissue decalcified in 30 to 40 days at 4° C exhibited a good preservation of hydrolytic and oxidative enzymes histochemically, but a few structural destruction in a long term decalcification was found in soft tissues and certain organs. 相似文献
7.
G. J. Van den Berg J. P. Van Wouwe A. C. Beynen 《Biological trace element research》1989,23(1):165-172
The effect of a high concentration (1%, w/w) of ascorbic acid in a Cu-adequate (150 μmol/kg) purified diet was studied in
rats. After 6 wk, ascorbic acid had significantly reduced Cu concentrations in muscle and bone. The estimated whole body content
of Cu in rats fed ascorbic acid was reduced by 20%. Within 1 d after oral administration of64Cu, the recovery of the dose in feces was increased in rats fed ascorbic acid, suggesting that the vitamin depresses intestinal
absorption of Cu.
After intraperitoneal (ip) administration of64Cu, the rate of loss of the dose from the body was decreased in rats fed ascorbic acid. This study suggests that the ascorbic
acid induces a decreased efficiency of intestinal Cu absorption, which in turn triggers mechanisms to preserve Cu in the body
stores. This is supported by the observation that the feeding of a Cu-deficient diet (5 μmol/kg) had similar effects, although
more pronounced. 相似文献
8.
Chrysovalantou Antonopoulou Kortessa Dimassi Ioannis Therios Christos Chatzissavvidis Ioannis Papadakis 《Acta Physiologiae Plantarum》2007,29(6):559-561
The objective of this research was to study the effect of the chelated form of the iron salt of ethylenediamine di-o-hydroxyphenylacetic acid (Fe-EDDHA) (6% Fe) on in vitro rooting of the rootstock GF-677. The iron salt of ethylenediamine
tetraacetic acid (Fe-EDTA) (12% Fe) of the MS basic medium was replaced by Fe-EDDHA, which was applied in three concentrations:
93.5, 187.0 and 280 mg l−1 (5.6, 11.2 and 16.8 mg l−1 Fe, respectively). For each treatment of Fe-EDDHA, the effect of ascorbic acid added in four concentrations (0, 0.1, 1.0
and 10 mg l−1) was studied. After 4 weeks of culture, the explants growing on the medium with 280 mg l−1 Fe-EDDHA gave the best rooting results. Regarding ascorbic acid, no clear stimulating effect on rooting was found. 相似文献
9.
Azza A. Tawfik Mohamed F. Mohamed 《In vitro cellular & developmental biology. Plant》2007,43(1):21-27
Nodular meristematic callus was induced on the basal cut surface of apical shoot explants of salvia cultured on Murashige
and Skoog (MS) medium supplemented with 4.5, 13.5, or 22.5 μM thidiazuron (TDZ). Cultures were incubated in the dark for 1 wk
and then transferred to light conditions for 4 wk. A higher percentage of explants developing callus was observed on medium
containing either 4.5 or 13.5 μM TDZ, although explants on 4.5 μM developed larger calluses. The callus was maintained on
medium containing 4.5 μM TDZ and 0.45 mM ascorbic acid. Shoot differentiation, after each of three successive maintenance
passages, was induced from callus grown on medium containing either 4.4 or 8.8 μM benzyladenine (BA). A greater number of
shoots were harvested from callus differentiated on BA (4.4 or 8.8 μM) medium with 0.45 mM ascorbic acid added. Shoots developed
roots on MS medium supplemented with 4.9 μM of indole-3-butyric acid. The addition of ascorbic acid to the shoot differentiation
medium enhanced rooting, number of roots per shoot, and survival rate. Approximately 75% in vitro plantlets were acclimatized to ex vitro conditions. Histological investigations confirmed both adventitious meristem initiation during the callus induction phase,
and subsequent organogenic shoot development on the differentiation medium. The novel protocol for the meristematic callus
induction and plant regeneration in this study may be useful for biotechnological applications for salvia improvement via
genetic transformation or mutagenesis and in vitro propagation approaches. 相似文献
10.
Anin vitro procedure for large scale multiplication ofBoswellia serrata Roxb. has been developed using cotyledonary node segments. In average 4 shoots per node were obtained on Murashige and Skoog's
(MS) medium containing 0.5 mg dm−3 6-benzylaminopurine (BAP) and 0.05 mg dm−3 napthaleneacetic acid (NAA) within 22 d. By repeated subculture technique 90–100 shoots per node could be obtained after
88 d of initial culture. Shoots could be rooted on MS medium containing 1/4 salts, 1% saccharose, and a combination of 0.5
mg dm−3 indole-3-butyric acid (IBA) and 0.25 mg dm−3 indole-3-acetic acid (IAA). Addition of antioxidants like polyvinylpyrrolidone (PVP-50 mg dm−3) and ascorbic acid (100 mg dm−3) in both multiplication and rooting media prevented browning of cultures. Approximately 80% of shoots rooted within 8–10
d. Rooted plantlets were kept for 15 d in culture bottles containing SoilriteTM irrigated with a nutrient solution containing 1/4 MS salts and finally transferred to pots containing soil: SoilriteTM (1∶1), mixture with 70% transplantation success. 相似文献
11.
An in vitro propagation protocol has been developed from mature lianas of Bauhinia valii. Browning was the major obstacle in the establishment of cultures. Explants collected during the growing season (April–June)
showed maximum browning; however, browning was minimal during the dormant phase. This problem was circumvented by soaking
the sterilized explants in a solution of antioxidant (50 mg l–1 ascorbic acid+75 mg l–1 citric acid). The explants were thereafter transferred to culture room conditions after an initial incubation in the dark
at 4 °C for 48 h. Shoot proliferation (58%), shoot number (4.5) and shoot length (35 mm) was best in Murashige and Skoog (MS)
medium supplemented with 2.5 μM kinetin + 100 mg l–1 adenine sulfate. Seasonal fluctuations significantly affected the proliferation potential of the explants. March– April was
found to be the best season for shoot initiation. Microshoots were rooted on a half-strength, growth regulator-free, agar-gelled
Murashige and Skoog medium after a dip in half-strength MS liquid medium containing 1-naph-thaleneacetic acid + indole-3-butyric
acid (10 μM). Rooted plantlets were potted and acclimatized under culture room conditions for 4 weeks before transfer to a polyhouse.
Received: 9 March 1998 / Revision received: 14 August 1998 / Accepted: 23 September 1998 相似文献
12.
Koszela-Piotrowska I Choma K Bednarczyk P Dołowy K Szewczyk A Kunz WS Malekova L Kominkova V Ondrias K 《Cellular & molecular biology letters》2007,12(4):493-508
Ion channels selective for chloride ions are present in all biological membranes, where they regulate the cell volume or membrane
potential. Various chloride channels from mitochondrial membranes have been described in recent years. The aim of our study
was to characterize the effect of stilbene derivatives on single-chloride channel activity in the inner mitochondrial membrane.
The measurements were performed after the reconstitution into a planar lipid bilayer of the inner mitochondrial membranes
from rat skeletal muscle (SMM), rat brain (BM) and heart (HM) mitochondria. After incorporation in a symmetric 450/450 mM
KCl solution (cis/trans), the chloride channels were recorded with a mean conductance of 155 ± 5 pS (rat skeletal muscle) and 120 ± 16 pS (rat brain).
The conductances of the chloride channels from the rat heart mitochondria in 250/50 mM KCl (cis/trans) gradient solutions were within the 70–130 pS range. The chloride channels were inhibited by these two stilbene derivatives:
4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) and 4-acetamido-4′-isothiocyanostilbene-2,2′-disulfonic acid (SITS).
The skeletal muscle mitochondrial chloride channel was blocked after the addition of 1 mM DIDS or SITS, whereas the brain
mitochondrial channel was blocked by 300 μM DIDS or SITS. The chloride channel from the rat heart mitochondria was inhibited
by 50–100 μM DIDS. The inhibitory effect of DIDS was irreversible. Our results confirm the presence of chloride channels sensitive
to stilbene derivatives in the inner mitochondrial membrane from rat skeletal muscle, brain and heart cells. 相似文献
13.
Summary A pot-culture experiment was undertaken to assess the physiological significance of ascorbic acid in relation to drought resistance
in two high-yielding varieties of rice — Taichung Native — 1 and I.R. 8. The soil-moisture stresses were maintained at 7–10
and 15–20 per cent moisture at field capacity. The wilting treatments were given only at tillering and shooting stages. Observations
pertaining to survivality of rice plants and determinations of ascorbic acid, acorbigen and ascorbic acid utilization in fresh
leaves were made.
The two varieties of rice,i.e. Taichung Native-1 and I.R. 8 were not identical in their drought tolerance. Taichung Native-1 was more drought resistant
which may be presumed in view of their differences in morphological make-up and demand for water at different stages of growth.
The leaves of Taichung Native-1 showed greater contents of ascorbic acid and ascorbigen following increased rate of ascorbic
acid utilization as compared to I.R. 8. These values were significantly reduced during shooting stage, a critical period to
drought. This confirms the significance of ascorbic acid towards drought resistance in plants with special reference to rice. 相似文献
14.
R. G. Mac Bride 《In vitro cellular & developmental biology. Plant》1989,25(7):617-620
Summary Addition of low concentrations of ascorbic acid (5 μg/ml to 10 μg/ml) to myogenic chick embryo cultures resulted in an early
fusion. At 30 h cultures receiving small amounts of ascorbic acid presented fusion rates 3 times that of the control. However,
control rates of fusion were not different from those of experimentals at 50 h. No such effect was seen with ascorbic acid
added at 24 h of culture, or with ascorbic acid addition to a calcium-deprived system. These findings demonstrate that the
calcium binding properties of ascorbic acid can induce precocious myogenic fusion. 相似文献
15.
Role of ascorbic acid in metabolism of rat testis and epididymis in relation to the onset of puberty
The metabolism of ascorbic acid, cholesterol, serum testosterone level and activities of 3Β and 17Β hydroxysteroid dehydrogenases
were studied in testis and Cauda epididymis of prepubertal, pubertal and postpubertal (5, 15, 30, 45, 55 and 60 day old) rats.
The data showed that serum testosterone levels and 3Β and 17Β hydroxysteroid dehydrogenases were increased with the age. The
ascorbic acid metabolism was found to be stabilized in testis at day 30 being comparable with the adult, whereas a spurt in
its metabolism occurred by day 45 and a significant depletion in ascorbic acid content in relation to the passage of the first
wave of spermatozoa through cauda epididymis. The results of this study clearly elucidate that ascorbic acid is involved in
metabolism of testis and epididymis in developing postnatal rats, in relation to the increasing demands for attaining a stable
hormonal milieu, and the onset of puberty and the passage of the first wave of spermatozoa,via the formation of its free radical monodehydroascorbic acid and charge transfer complex mechanism 相似文献
16.
Differences in growth response to hydrocortisone and ascorbic acid by human diploid fibroblasts 总被引:2,自引:0,他引:2
David W. Rowe Barbra J. Starman Wilfred Y. Fujimoto Robert H. Williams 《In vitro cellular & developmental biology. Plant》1977,13(12):824-830
Summary The effects of hydrocortisone and ascorbic acid on growth parameters were measured in human diploid skin fibroblasts from
fetal and adult donors. In the presence of culture medium containing 10% fetal bovine serum, 0.3 μM hydrocortisone produced
a 20% increase in the population growth rate and a 50 to 70% increase in the confluent density of fibroblasts from adult donors.
Daily addition of 28 μM ascorbic acid also stimulated the population growth rate and cell density at confluency. The effects
of hydrocortisone and ascorbic acid on the final cell density were additive. The action of hydrocortisone was restricted to
cells in log-phase growth, whereas ascorbic acid affected cells in both the log and the postconfluent phases of the growth
cycle. In fibroblasts from fetal donors, ascorbic acid was stimulative but hydrocortisone was not. The data suggest that whereas
both compounds stimulate cell growth in an additive manner, they do so by different cellular mechanisms.
This investigation was supported in part by USPHS Grants AM 02456, AM 05020 and AM 15312, and by the Kroc Foundation, No.
UW 63-2986. Dr. Rowe is a fellow of the Helen Hay Whitney Foundation. Dr. Fujimoto is a recipient of a Research Career Development
Award, AM 47142, from NIAMDD. 相似文献
17.
Yingjun Liao Jun Zhang Yaping Jin Chunwei Lu Gexin Li Fei Yu Xuping Zhi Li An Jun Yang 《Biometals》2008,21(1):1-8
The aim of this study was to explore the therapeutic efficacies of combined use of meso-2,3-dimercaptosuccinic acid (DMSA)
with calcium and ascorbic acid in the treatment of mild to moderately lead-intoxicated mice. Female albino mice were exposed
to lead by drinking water contaminated with 0.1% (moderate lead exposure) or 0.05% (mild lead exposure) lead acetate. After
the cessation of lead exposure, mice were supplemented by gavage with saline solution, 50 mg/kg body weight (b.w) DMSA, 100 mg/kg
b.w DMSA, calcium and ascorbic acid, or 50 mg/kg b.w DMSA and calcium as well as ascorbic acid, respectively. Atomic absorption
spectrophotometric method was used to analyze lead levels in blood, bone, liver, kidney and brain. Activities of blood δ-aminolevulinic
acid dehydratase (ALAD) were determined by colorimetric method. DMSA supplemented alone could reduce lead levels in both soft
tissues and bone and reverse lead-inhibited activities of blood ALAD in mild to moderately lead-intoxicated mice. On the other
hand, combined use of DMSA with calcium and ascorbic acid achieved better therapeutic efficacies in mobilizing lead in blood,
liver and kidney, and reversing lead-inhibited activities of blood ALAD in moderately lead intoxicated mice than DMSA supplemented
alone. Moreover, the better therapeutic efficacies were also found in mildly lead intoxicated mice in mobilizing lead in blood
and bone achieved by combined use of DMSA with calcium and ascorbic acid. Combined use of DMSA with calcium and ascorbic acid
seems to be the better choice in the treatment of mild to moderate lead-intoxication. 相似文献
18.
The goal of this research was to measure in vitro the inhibitory constants of the antioxidants ascorbic and uric acid in urine, with lucigenin enhanced chemiluminescence (CL)
in Fenton’s system. Maximum CL emission is registered in urine containing H2O2 (5·10−4 M), Fe2+ (5·10−5 M), EDTA (5·10−5 M), and chemical enhancer lucigenin (10−4 M) at pH 5.5 and 36°C. Ascorbic acid exhibits up to 4-fold stronger antioxidant effect than uric acid. The constants of antioxidant
inhibition in urine were measured at concentrations 10−3 and 10−4 M: for ascorbic acid, 5.92 ± 0.04 and 24.05 ± 1.82 μmol·sec−1; for uric acid, 1.60 ± 0.02 and 21.45 ± 0.97 μmol·sec−1, respectively. Three phases of CL kinetics of urine are well observed: spontaneous CL (0–10 sec), fast flash of CL (10–50
sec), and latent period (50–300 sec). The antioxidant efficiency of ascorbic and uric acids in the final stage of catabolic
processes in the body is discussed.
Published in Russian in Biokhimiya, 2006, Vol. 71, No. 8, pp. 1062–1065. 相似文献
19.
Anne Nègre-Salvayre Laurence Mabile Jean Delchambre Robert Salvayre 《Biological trace element research》1995,47(1-3):81-91
Low-density lipoproteins (LDL) mildly oxidized by copper ions or UV radiations exhibit a cytotoxic effect to cultured endothelial
cells. Rutin, a polyphenolic flavonoid, ascorbic acid, and α-tocopherol were able to inhibit the peroxidation of LDL and their
subsequent cytotoxicity. The mixture of the three compounds (rutin/ascorbic acid/α-tocopherol, 4/4/1) exhibited a supra-additive
antioxidant effect. The inhibition of the cytotoxic effect was well correlated with that of TBARS formation. Another important
conclusion is that these antioxidants were able to prevent directly at the cellular level the cytotoxic effect of oxidized
LDL, since cells preincubated with them were protected against the cytotoxic effect of previously oxidized LDL. The protective
effect of antioxidants was limited because of their own toxicity. The antioxidant mixture permitted a maximal cytoprotective
effect with relatively lower concentrations to be obtained and the cytotoxicity of high concentrations to be avoided. In conclusion,
rutin, ascorbic acid, and α-tocopherol constitute two lines of defense in protecting cells against injury owing to oxidation
of LDL (1) at the LDL level, by inhibiting the LDL oxidation and the subsequent cytotoxicity, and (2) at the cellular level,
by protecting the cells directly, i.e., by increasing their resistance against the cytotoxic effect of oxidized LDL. 相似文献
20.
Lipid peroxidation (LP) and antioxidant levels were studied in the chromatically distinct inner (zona reticularis) and outer (zona fasciculata + zona glomerulosa) zones of the guinea pig adrenal cortex. Ferrous ion (Fe2+) produced a concentration-dependent (10(-5) to 10(-3) M) stimulation of microsomal LP in both zones, but LP, as estimated by malonaldehyde production, was far greater in the inner zone. Although cytosolic ascorbic acid content was similar in the two zones, microsomal tocopherol levels were approx 4 times greater in the outer than inner zone. Subphysiological concentrations of ascorbic acid, like Fe2+, initiated LP to a greater extent in inner than outer zone microsomes; optimal stimulation of LP by ascorbic acid occurred at concentrations of 100-200 microM in both zones. Physiological concentrations of ascorbic acid (1-5 mM), by contrast, did not initiate LP and, in fact, markedly inhibited Fe2+-induced LP in both inner and outer zone microsomal preparations. Outer zone microsomes were more sensitive to the antioxidant effects of ascorbic acid than were inner zone preparations. Addition of alpha-tocopherol to inner zone microsomal suspensions inhibited Fe2+-induced LP. The results indicate that there are regional differences in adrenocortical LP which may be caused by differences in tocopherol content. alpha-Tocopherol may serve important antioxidant functions within the adrenal cortex, thereby contributing to the functional zonation of the gland. 相似文献