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101.
Cholinesterase activities in rat forebrain, erythrocytes, and plasma were assessed after a single oral administration of metrifonate
or dichlorvos. In 3-month-old rats, the dichlorvos (10 mg/kg p.o.)-induced inhibition of cholinesterase reached its peak in
brain after 15–45 min and after 10–30 min in erythrocytes and plasma. Cholinesterase activity recovered rapidly after the
peak of inhibition, but did not reach control values in brain and erythrocytes within 24 h after drug administration. The
recovery of plasma cholinesterase activity, in contrast, was already complete 12 h after dichlorvos treatment. Metrifonate
(100 mg/kg p.o.) had qualitatively similar inhibition kinetics as dichlorvos, albeit with a slightly delayed onset. Peak values
were attained 45–60 min (brain) and 20–45 min (blood), after drug administration. Apparently complete recovery of cholinesterase
activity was noted in both tissues 24 h after treatment. The dose-dependence of drug-induced inhibition of cholinesterase
in rat blood and brain was determined at the time of maximal inhibition, i.e., 30 min after dichlorvos treatment and 45 min
after metrifonate treatment. The oral ED50 values obtained for dichlorvos were 8 mg/kg for brain and 6 mg/kg for both erythrocyte and plasma cholinesterase. The corresponding
oral ED50 values for metrifonate were 10 to 15 times higher, i.e., 90 mg/kg in brain and 80 mg/kg in erythrocytes and plasma. In rats
deprived of food for 18 h before drug treatment, the corresponding ED50 values for metrifonate were 60 and 45 mg/kg, respectively, indicating an about two-fold higher sensitivity of fasted rats
to metrifonate-induced cholinesterase inhibition compared to non-fasted rats. Compared to 3-month-old rats, 19-month-old rats
showed a higher sensitivity towards metrifonate and dichlorvos. At the time of maximal inhibition, there was a strong correlation
between the degree of cholinesterase inhibition in brain and blood. These results demonstrate that single oral administration
of metrifonate and dichlorvos induces an inhibition of blood and brain cholinesterase in the conscious rat in a dose-dependent
and apparently fully reversible manner. While the efficiency of a given dose of inhibitor may vary with the satiety status
or age of the animal, the extent of brain ChE inhibition can be estimated from the level of blood ChE activity. 相似文献
102.
Pelouch Václav Kolář František Khuchua Zaza A. Elizarova Galina V. Milerová Marie Ošt'ádall Bohuslav Saks Valdur A. 《Molecular and cellular biochemistry》1996,163(1):67-76
The effect of chronic administration of -guanidinopropionic acid (GPA) on the protein profiling, energy metabolism and right ventricular (RV) function was studied in the rat heart during the weaning and adolescence period. GPA was given in tap water (1–1.5%) using pair drink controls. The feeding of animals with GPA solution for a six week period resulted in elevation of heart to body weight ratio due to body growth retardation. GPA accumulated in the myocardium up to 67.37 ± 5.3 moles.g dry weight and the tissue content of total creatine, phosphocreatine and ATP was significantly decreased to 15%, 9% and 65% of control values respectively. Total activity of creatine kinase (CK) was not changed, but the proportion of mitochondrial (Mi) CK isoenzyme was decreased; the percentage of MB isoenzyme of CK was significantly higher. GPA treatment resulted in an elevation of the content of cardiac collagenous proteins and decrease of non-collagenous proteins in the heart; in parallel, a decrease of the collagen I to collagen III ratio was detected. The function of the RV was assessed using an isolated perfused heart with RV performing pressure-volume work. As compared to pair-drink controls, RV function was significantly impaired the GPA group: at any given right atrial filling pressure, the RV systolic pressure and the rate of pressure development were decreased by almost a factor of two. Elevation of the RV diastolic pressure with increasing pulmonary artery diastolic pressure was also significantly steeper in the GPA group which also showed decrease of cardiac output, especially at high outflow resistance. It may be assumed that chronic administration of GPA deeply influenced metabolic parameters, protein profiles and contractile function of the developing heart. On the other hand, concentrations of glucose, total lipids and triglycerides in blood plasma were not affected. All these data confirm the concept that the CK system is of central importance both for heart function and for the regulation of normal growth of cardiac myocytes. 相似文献
103.
Maria Claudia Gonzalez Deniselle Susana L. Gonzalez Gerardo G. Piroli Analia E. Lima Alejandro F. De Nicola 《Cellular and molecular neurobiology》1996,16(1):61-72
Summary 1. Wobbler mice suffer an autosomal recessive mutation producing severe motoneuron degeneration and dense astrogliosis, with
increased levels of glial fibrillary acidic protein (GFAP) in the spinal cord and brain stem. They have been considered animal
models of amyotrophic lateral sclerosis and infantile spinal muscular atrophy.
2. Using Wobbler mice and normal littermates, we investigated the effects of the membrane-active steroid Lazaroid U-74389F
on the number of GFAP-expressing astrocytes and glucocorticoid receptors (GR). Lazaroids are inhibitors of oxygen radical-induced
lipid peroxidation, and proved beneficial in cases of CNS injury and ischemia.
3. Four days after pellet implantation of U-74389F into Wobbler mice, hyperplasia and hypertophy of GFAP-expressing astrocytes
were apparent in the spinal cord ventral and dorsal horn, areas showing already intense astrogliosis in untreated Wobbler
mice. In control mice, U-74389F also produced astrocyte hyperplasia and hypertophy in the dorsal horn and hyperplasia in the
ventral-lateral funiculi of the cord.
4. Givenin vivo U-74389F did not change GR in spinal cord of Wobbler or control mice, in line with the concept that it is active in membranes
but does not bind to GR. Besides, U-74390F did not compete for [3H]dexamethasone binding when addedin vitro.
5. The results suggest that stimulation of proliferation and size of GFAP-expressing astrocytes by U-74389F may be a novel
mechanism of action of this compound. The Wobbler mouse may be a valuable animal model for further pharmacological testing
of glucocorticoid and nonglucocorticoid steroids in neurodegenerative diseases. 相似文献
104.
T. Kupila-Rantala J. T. Dabek M. Hyvönen-Dabek 《Biological trace element research》1996,55(1-2):173-179
A new technique for investigation of elemental concentrations in subfractions of blood plasma is presented. The method is
composed of the ultrafiltration of plasma in the presence of ethylenediaminetetraacetic acid (EDTA) and the measurement of
the elemental composition by proton-induced X-ray emission (PIXE). The blood samples were collected from both healthy persons
and patients suffering from breast cancer. The main emphasis in this study was on the determination of loosely bound copper
(Cu) in plasma subfractions containing substances with molecular mass under 10,000, but zinc (Zn) and iron (Fe) contents of
these fractions were also determined. The detection limits obtained with this method for Cu, Zn and Fe were ≈10 ppb (wet wt). 相似文献
105.
A simple and reliable method is described which combines ultrafiltration technique with atomic absorption spectrophotometry
to determine the Zn fractions in human blood plasma and seminal plasma. Ultrafiltrable, loosely bound, and firmly bound Zn
can be measured using this method in the presence or absence of ethylene-diaminetetraacetic acid (EDTA). The YMT membranes
for the ultrafiltration must be rinsed thoroughly before use. In contrast to Zn in blood plasma, a large part of Zn in the
seminal plasma was found to be ultrafiltrabe. This method can be applied to study the physiologically active part of Zn in
body fluids related to various disease states. 相似文献
106.
Satoshi Muraki Masahiro Yamasaki Yoshito Ehara Kunio Kikuchi Kunihiro Seki 《European journal of applied physiology and occupational physiology》1996,74(5):481-483
The purpose of the present study was to examine the effect of maximal arm exercise on the skin blood circulation of the paralyzed
lower limbs in persons with spinal cord injury (PSCI). Eight male PSCI with complete lesions located between T3 and L1 performed
graded maximal arm-cranking exercise (MACE) to exhaustion. The skin blood flux at the thigh (SBFT) and that at the calf (SBFC)
were monitored using laser-Doppler flowmeter at rest and for 15 s immediately after the MACE. The subject's mean peak oxygen
uptake and peak heart rate was 1.41 ± 0.22 1·min−1 and 171.6 ± 19.2 beats·min−1, respectively. No PSCI showed any increase in either SBFT or SBFC after the MACE, when compared with the values at rest.
These results suggest that the blood circulation of the skin in the paralyzed lower limbs in PSCI is unaffected by the MACE. 相似文献
107.
采用地高辛标记生长抑素反意RNA探针经原位杂交和显色后,光学显微镜下观察生长抑素mRNA在大鼠脊髓内的定位。结果显示:脊髓内含有大量呈紫蓝色的生长抑素mRNA阳性神经细胞,岍性磷酸酶反应产生 相似文献
108.
M. C. Léglise P. Darodes de Tailly J. L. Vignot M. A. Le Bot A.-M. Le Roux C. Riché 《Cell biology and toxicology》1996,12(1):39-53
A cellular model of hematopoiesis which would be more convenient than bone marrow (BM) progenitors and directly relevant to human pathology is needed in order to investigate xenobiotic toxicity. Human umbilical cord blood (HCB), previously shown to be able to repopulate BM, provides a powerful in vitro model of normal human hematopoiesis. In order to validate the use of normal HCB progenitors as targets for dose-related myelosuppression, we used clonogenic assays and expansion in a liquid culture of progenitor-enriched cell suspensions from HCB. A series of 8 reference molecules, doxorubicin, cytosine-arabinoside, 5-fluorouracil, 3-azido-3-deoxythymidine, acetylsalicyclic acid, sodium valproate and two cephalosporin antibiotics, were tested. In vitro 50% inhibition concentrations (IC50) were compared to those observed or reported with BM progenitors, and to the values of plasma concentrations from treated patients. HCB progenitors as in vitro targets for cytotoxic molecules were easy to access and handle, and their use was sensitive, specific and reproducible. They gave results similar to BM progenitors and allowed a qualitative approach to cellular metabolism and toxicity using morphological, flow cytometric and chromatographic methods.Abbreviations ARA-CC
cytosine arabinoside
- AS
acetylsalicylic acid
- AZTT
3-azido-3-deoxythymidine
- BFUU
burst-forming units
- BM
bone marrow
- CFU
colony-forming units
- DOXX
doxorubicin
- FU
5-fluorouracil
- glyAA
glyAcophorin A
- HCB
human umbilical cord blood
- IU
international units
- PCMEM
human placenta-conditioned medium
- VA
sodium valproate 相似文献
109.
本文对103例锰作业工人测定了血液流变学中的七项指标,结果表明:全血粘度(高切、低切)、血浆粘度、红细胞压积、纤维蛋白原、红细胞电泳、血小板粘附、血沉等项指标,均明显高于正常对照组(P<0.01),证实锰作业工人普遍存在高粘滞血症,为临床治疗锰中毒开辟新的途径提供了依据。对其中的52例锰中毒(包括症状较重的观察对象),用清栓酶治疗后,复查其七项指标与治疗前比较,均有明显下降(P<0.01),其症状与体征得以改善,进一步说明清栓酶是治疗锰中毒的理想药物之一。 相似文献
110.
脐血浆治疗大鼠实验性肝衰竭及其机制的研究 总被引:2,自引:0,他引:2
本文采用脐血浆治疗实验性肝衰竭大鼠模型,并与成人血浆的疗效进行了比较。结果表明,脐血浆降低大鼠死亡率、血谷丙转氨酶水平,总胆红素浓度及使甲胎蛋白水平升高均明显高于成人血浆的作用(P<0.05).肝脏病理组织学也显示脐血浆具有减轻病理损害和较快修复坏死组织的作用。提示脐血浆中含有促进肝细胞再生的因子,具有显著提高实验性大鼠肝衰竭的存活率。 相似文献