首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
  • 1.1. Metabolic rate (MR) and water budget (WB) components of cave and camel crickets are directly related to size and temperature.
  • 2.2. MR increases most rapidly with size for insects in general followed by cave crickets (females > males), and lastly, camel crickets (no sex differences).
  • 3.3. Metabolic thermal sensitivity of cave crickets (males > females) is much greater than camel crickets.
  • 4.4. WB components parallel MR relations.
  相似文献   

2.
  • 1.1. Analysis of camel bile revealed that it is highly concentrated.
  • 2.2. The molar fraction of phospholipids in camel bile was low and cholesterol was very high relative to rat bile.
  • 3.3. Cholate is the main primary bile acid secreted. Moderate quantities of the secondary bile acid deoxycholate were found but no lithocholate was detectable possibly secondary to rapid recycling of the bile acid pool in the enterohepatic circulation.
  • 4.4. Glycoconjugated bile acids predominated over tauroconjugates.
  • 5.5. The hepatic bile from the camel may be concentrated as part of the general mechanism of water conservation exhibited by that species. The increased concentration of bile acids helps maintain cholesterol in solution, thus reducing lithogenicity.
  相似文献   

3.
  • 1.1. Species differences exist in ferrihemoglobin reduction rates in bird and mammalian red cells, bird erythrocytes being very active reducers.
  • 2.2. Glucose and lactate enhance ferrihemoglobin reduction. In horse and quail red cells β-hydroxybutyrate has this effect as well.
  • 3.3. Malate and pyruvate do not enhance ferrihemoglobin reduction.
  • 4.4. Plasma addition to red cell suspensions enhances ferrihemoglobin reduction; addition of lactate mimics this effect in all species except the dog.
  • 5.5. Incubation conditions are very important for measuring ferrihemoglobin reduction. Especially the presence of bicarbonate ions is essential. In our experiments no inhibition of reduction rates by chloride ions is found.
  • 6.6. Mitochondrial NADH production does not play a role in ferrihemoglobin reduction in bird red cells.
  相似文献   

4.
  • 1.1. Cat plasma prothrombin and partial thromboplastin times are faster than human. Thromboplastin generation tests are very similar.
  • 2.2. Factors VIII and V assay 24 and 13 times the human standard. Cat factors VII, X. IX, XI and XII assayed at 2.5 to 4 times human. Factors I, II and XIII fell within the human range and Fletcher was extremely low.
  • 3.3. One cat lacked factor XII and showed a prolonged APTT and clotting time.
  • 4.4. Cat profibrinolysin was activated by streptokinase but not by urokinase.
  • 5.5. Cat platelets aggregated with the usual human aggregation agents with the exception of thrombin and ristocetin.
  • 6.6. Cat erythrocytes were smaller and more numerous than human.
  • 7.7. Leukocyte counts were quite variable.
  • 8.8. Serum protein electrophoretic patterns differed from human in the greater migration of albumin and the presence of numerous unidentified bands.
  • 9.9. Biochemical tests showed high sodium and chloride values.
  相似文献   

5.
  • 1.1. The taurine content of erythrocytes from 15 avian species contained levels of taurine in the range of 20–70 mmol/kg of hemoglobin, about 100-fold that of mammalian red blood cells.
  • 2.2. This high taurine content did not appear to be related to the nucleation of these cells as nucleated amphibian erythrocytes and human reticulocytes contained low levels.
  • 3.3. The erythrocytes lacked cysteine sulfinic acid decarboxylase, a key enzyme in the synthesis of taurine from cysteine, indicating a probable lack of synthetic capabilities.
  • 4.4. The cells were able to accumulate labeled taurine against a concentration gradient. This uptake was inhibited by β-alanine and was Na+-dependent.
  • 5.5. When incubated in hypotonic medium, the cell volume of pigeon erythrocytes rapidly increased and was followed by a much slower return to normal size. The cell volume reduction was accompanied by a slow efflux of taurine into the medium.
  • 6.6. These data suggest that taurine plays a role in cell volume maintenance and osmotic regulation in avian erythrocytes.
  相似文献   

6.
  • 1.1. Preparation, purification and characterization of a phosphoglycolate phosphatase (PGP)3 isoenzyme from human erythrocytes was achieved by DEAE-Sepharose CL.-6B chromatography and isoelectric focusing using carrier ampholytes. pH 4–6.
  • 2.2. The isoenzyme has an isoelectric point of 5.00 ± 0.05 and could be purified 33.000 fold to a specific activity of 32.7 U/mg of protein. It represents the PGP phenotype 1 consisting of a single isoenzyme.
  • 3.3. The enzyme is composed of two subunits (mol. wt 35,000) which are identical and not connected by SS-bridges.
  • 4.4. At 4°C the isoenzyme is more stable in the pH range of 7–9 than at acid pH values.
  • 5.5. Incubation at 30 and 40°C for 4 hr does not affect the activity of the isoenzyme.
  • 6.6. It has a Km-value of 0.28 mM for phosphoglycolate (PG) as substrate.
  相似文献   

7.
  • 1.1. Glutathione S-transferases have been purified (18-fold) in 65–70% yield from the liver of one humped camel using affinity chromatography on glutathione-linked agarose.
  • 2.2. Chromatofocusing technique resolves the glutathione S-transferases into seven distinct isoenzymes with apparent pI of 8.7, 8.4, 8.0, 7.8, 7.3 and 6.5.
  • 3.3. The major isoenzyme (pI 8.7) which accounted for over 95% of the total activity was composed of two identical subunits of molecular mass 24,000 and was immunologically similar to the other six isoenzymes.
  • 4.4. The substrate specificities and the effect of various inhibitors on the activity of the abundant camel liver isoenzyme were also examined.
  相似文献   

8.
  • 1.1. Superoxide dismutase, reduced glutathione and lipid peroxides levels were determined in the erythrocytes of multiple sclerosis patients.
  • 2.2. Superoxide dismutase activity and the malonyldialdehyde production rate were found to be significantly enhanced.
  • 3.3. The isoelectric focusing pattern of Superoxide dismutase from multiple sclerosis and normal subjects erythrocytes was substantially overlapping.
  • 4.4. Our results indicate the occurrence of a higher susceptibility of multiple sclerosis erythrocytes to lipid peroxidation.
  相似文献   

9.
  • 1. The equilibria and kinetics of oxygen binding by blood and hemoglobin from adult and fetal caecilians,Typhlonectes compressicauda, have been measured.
  • 2. The oxygen affinity of fetal blood is higher than that of adult blood.
  • 3. Electrophoresis of adult and fetal hemoglobins suggests that they may be identical: a major and minor component occurs in each.
  • 4. Adult and fetal hemoglobins have identical oxygen equilibria. Stripped hemoglobins have a high oxygen affinity and no Bohr effect between pH 6.5 and 10.0. An “acid”, reversed Bohr effect is present below pH 6.5. The addition of 1 mM ATP reduces the oxygen affinity markedly and produces a moderate, normal Bohr effect.
  • 5. The major nucleoside triphosphate in fetal and adult erythrocytes is adenosine triphosphate: about 10% of the nucleoside triphosphates is guanosine triphosphate. Adult erythrocytes contain 3 times as much ATP as do the fetal erythrocytes.
  • 6. The fetal to maternal shift in the oxygen equilibrium is mediated entirely by the difference in ATP content of the maternal and fetal red blood cells.
  相似文献   

10.
  • 1.1. On the basis of its immunoreactivity with a polyclonal antiserum to dog prostate kallikrein in Western blot experiments, a 30 kDa protein was purified from the pancreas of the dog using ion-exchange and gel filtration chromatography.
  • 2.2. That protein was identified as the anionic trypsin by its NH2-terminal amino acid sequence.
  • 3.3. The immunoreaction occurred despite an overall amino acid homology which was limited to 39% between the prostate kallikrein and anionic trypsin.
  • 4.4. Otherwise, the anti-prostatic kallikrein antiserum was rather specific since it did not react with dog cationic trypsin, dog renal kallikrein and human prostate specific antigen.
f  相似文献   

11.
  • 1.1. Nicotine at 10 mM, but not caffeine or theophylline, reduced by 20% the overshoot of the Na+-dependent d-glucose transport in ratjejunal brush border membrane vesicles.
  • 2.2. Since nicotine did not affect the transport of Na+, its inhibition on Na+-dependent d-glucose transport must be due to a direct effect upon the d-glucose transport system.
  • 3.3. Folate transport in these membrane vesicles was found to a be a free diffusion process at pH 7.4.
  • 4.4. Neither caffeine, theophylline nor nicotine has any effect on folate transport.
  相似文献   

12.
  • 1.1. Oxygen carrying capacity and parameters of erythrocyte-oxygen binding are similar for a range of elasmobranchs with markedly different swimming behaviour.
  • 2.2. Erythrocyte nucleotide components in sharks include the allosteric hemoglobin modifiers GTP and ATP in similar ratios, and the total pool appears independent of locomotory activity. A rhinobatoid ray had no detectable erythrocyte trinucleotides, but had an appreciable pool of AMP together with IMP.
  • 3.3. There was no evidence for either urea or NaCl modulation of hemoglobin function in erythrocytes from a carcharhinid shark.
  • 4.4. These observations lead to the conclusion that parameters of the oxygen transport system in elasmobranchs are highly conserved.
  相似文献   

13.
  • 1.1. The specific activity of GMP synthetase was measured in several human tissues and found to be highest in cultured skin fibroblasts, followed by bone marrow, leukocytes, erythrocytes. placenta, and liver.
  • 2.2. The enzyme from fibroblasts was purified approximately 50-fold by ammonium sulfate fractionation and gel filtration.
  • 3.3. The Km values were determined to be 4.9μM for XMP, 270μM for ATP. and 340 μM for glutamine.
  • 4.4. Ammonium sulfate could replace glutamine as the amino donor but was much less efficient.
  • 5.5. The enzyme was specific for ATP as the energy source.
  • 6.6. Unlike the calf thymus enzyme, the human enzyme has no requirement for a reduced sulfhydryl compound.
  • 7.7. Human GMP synthetase is inhibited by ATP, dATP, azaserine, and hydroxylamine.
  相似文献   

14.
  • 1.1. Isoelectric points of human and bovine lactoferrins were evaluated by Rotofor and chromatofocusing analysis.
  • 2.2. By Rotofor, the isoelectric value of human lactoferrin fraction was determined at 8.7 and that of bovine lactoferrin at 8.8.
  • 3.3. By chromatofocusing analysis, human and bovine lactoferrins showed different elution patterns. Human lactoferrin was eluted at pH 6.8-8 and bovine lactoferrin eluted at pH 8.2–8.9.
  相似文献   

15.
  • 1.1. To date, only a few authors have assayed the agglutinic activity of marine algae against fish erythrocytes, and in these cases, mainly against freshwater fish.
  • 2.2. For the first time, the hemagglutinic activity of 70 seaweeds (29 brown, 37 red and four green algae) against erythrocytes of 16 seaflsh species is reported.
  • 3.3. The presence of agglutinins was demonstrated in 100% of algae assayed, against at least one of the different types of erythrocytes tested.
  • 4.4. The results obtained confirm the presence of receptors for algae agglutinins on the surface of the erythrocytes of the fish studied.
  • 5.5. This could be useful in establishing the origins of fish populations, as these serological differences could distinguish between populations of cultivated and wild fish.
  相似文献   

16.
  • 1.1. The time-course of cumene hydroperoxide-induced changes in lipid peroxidation, protein sulfhydryl groups and chemiluminescence intensity was determined in human erythrocytes.
  • 2.2. Increase in lipid peroxidation was maximal within 60 min of incubation and was paralleled by a decrease in protein sulfhydryl groups and an increase in chemiluminescence formation.
  • 3.3. A standard assay system was established to investigate the protective effects of antioxidants and scavenger compounds on cumene hydroperoxide-induced chemiluminescence formation.
  • 4.4. Chain-breaking antioxidants (i.e. butylated hydroxytoluene) and sulfhydryl compounds (i.e. dithiothreitol) were able to suppress chemiluminescence formation.
  • 5.5. Our results suggested that secondary free radicals, as well as sulfhydryl groups of proteins are involved in cumene hydroperoxide-induced chemiluminescence formation.
  相似文献   

17.
  • 1.1. About 40% of IgG is precipitated when heparin is added to human plasma at pH 5.4, while only a little IgM and no IgA are precipitated.
  • 2.2. The precipitation of purified IgG by heparin is pH-dependent and follows a sigmoid curve between pH 7.0 and 5.0.
  • 3.3. The precipitate has a constant molar ratio heparin: IgG, independent of pH or the amount of heparin that is added.
  • 4.4. The precipitate does not redissolve at high heparin concentrations.
  • 5.5. The heavy chains of IgG precipitate also at pH 5.4, but this precipitate redissolves in excess heparin.
  • 6.6. Light chains do not precipitate and the Fab and Fc fragments are only partly precipitated.
  相似文献   

18.
  • 1.1. A choriolytic enzyme was isolated from the hatching medium of the pike, Esox lucius.
  • 2.2. The enzyme is defined as hatching enzyme.
  • 3.3. The molecular weight of the enzyme is 24,000.
  • 4.4. The enzyme is a glycoprotein containing 2% carbohydrate.
  • 5.5. Its isoelectric point is 6.5.
  • 6.6. The pH optimum is around pH 8.
  • 7.7. The enzyme molecule contains two disulfide bonds but no free cysteine.
  • 8.8. Inhibitor studies and metal analysis show that the enzyme is a zinc-metalloprotease.
  相似文献   

19.
  • 1.1. The paper describes evolutionary differences in energetics between the raccoon dogs originated from islands (Japan) and mainlands (eastern Asia).
  • 2.2. The Japanese raccoon dog is specialized to live in a temperate marine climate; it has a stomach of small volume, thin fur coat with low insulation, specialized diet and a poor ability to alter its body energy reserves seasonally.
  • 3.3. The raccoon dog living in mainland is more generalized, and thus also well-adapted to survive extreme climate of northern latitudes.
  • 4.4. The results confirm the previous conclusions made from chromosomal analyses that the Japanese raccoon dog has evolved from the mainland form.
  相似文献   

20.
  • 1.1. Studies characterizing glucose transport in the frog sartorius were performed.
  • 2.2. For nonstimulated and stimulated muscles, intracellular 2-deoxyglucose exceeded 2-deoxyglucose-6-phosphate at 15 min, showed little further increase, and was maintained below the extracellular concentration for 2 hr.
  • 3.3. Accumulated 2-deoxyglucose-6-phosphate did not inhibit glucose transport.
  • 4.4. Unlike in adipocytes, basal and stimulated 2-deoxyglucose transport showed no difference in sensitivity to N-carbobenzoxy-glycyl-l-phenylalaninamide.
  • 5.5. Phenylarsine oxide blocked contraction-enhanced 2-deoxyglucose uptake.
  • 6.6. These results suggest that the glucose transporter of the sartorius exhibits auto-regulation, and that basal transport is not regulated by the same process as in adipocytes.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号