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.
The kinetics of pooling of platelets in the spleen may be used to measure spleen function. However, pooling of platelets in other organs, especially the liver, may affect these kinetic measurements. We have therefore compared, in man and baboon, the kinetics of 111In-labelled platelets and 111In-labelled red cells in the liver and spleen during the first 60 min after reinjection. This was determined in vivo with a scintillation camera and computer-assisted image analysis. Organ radioactivity was expressed as a percentage of that of the whole body. In both humans and baboons, the spleen accumulated many more platelets than red cells. Also, the red cells equilibrated more rapidly. The presence of a splenic platelet pool was thus confirmed. In contrast, the percentages of labelled platelets and labelled red cells in the liver were similar in both species. In both species, the sum total of labelled platelets in the circulation, i.e. recovery, and that quantified in the spleen at equilibrium, were equal to approximately 100%. These results confirm the presence of the exchangeable splenic platelet pool, and indicate that there are no significant exchangeable platelet pools in either the liver or any other organs.  相似文献   

2.
We have developed a new liver scanning agent (Ga-68 human serum albumin microspheres) in a convenient kit for use in positron emission computed tomography (PET). In this study, this scanning agent was evaluated for clinical usefulness as a function test for the reticuloendothelial system. A dose of 5 micrograms/kg (1-2 mCi) of Ga-68 microspheres was injected intravenously to 25 patients, 11 with chronic hepatitis and 14 with liver cirrhosis, and 5 normal volunteers for PET imaging of the liver and spleen using HEADTONE-III (SET 120W). The volumes of the liver and the spleen and the uptakes of Ga-68 microspheres were calculated as an index of the reticuloendothelial system function. In liver cirrhosis the liver volume estimated by PET was decreased and the spleen volume was increased. Both the liver uptake rate and differential absorption ratio (DAR) of the radioactivity were decreased corresponding with the degree of chronic liver disease. The spleen uptake rate was increased with progression of chronic liver diseases, but there was no difference in DAR between normal volunteers and patients with chronic liver disease. it was concluded that PET using Ga-68 microspheres is useful in the evaluation of the function of the reticuloendothelial system.  相似文献   

3.
GLASS GB  BOYD LJ  GELLIN GA 《Blood》1955,10(2):95-114
1. The distribution of radioactive vitamin B12 in humans was studied by scintillation counting of radioactivity over various skin projections of underlyingorgans in five individuals, following parenteral administration of radioactivevitamin B12. The results of these investigations showed that the scintillation surface measurements of the radioactivity following parenteral administration ofradioactive vitamin B12 may be profitably applied to the study of the metabolicturnover of vitamin B12 under normal and pathological conditions in humans.

2. In two young normal control subjects over 96 per cent of the parenterallyadministered radioactive vitamin B12 (5 and 10 µg. containing 0.925 µc. of Co60)disappeared from the site of the intramuscular injection within three to fourhours, and during that time radioactivity rose to its peak value over the areascorresponding to kidney, spleen and iliac crest, and somewhat later over the muscles of the extremities. Subsequently, a gradual decline of radioactivity wasobserved over the spleen, kidney and extremities, so that at the end of threemonths in the normal subject from to of radioactivity as compared to peakvalues was observed over the spleen and left kidney and about over the calfmuscle.

The projection areas of the liver differed from all the other areas of the bodyin requiring about five to six days to build up the peaks of radioactivity. Theseexceeded counts over the kidney and spleen about 2 times, counts over theiliac crest approximately 7 times, and those over the calves about 17 times. Thedecline of radioactivity over the liver and iliac crest was very slow and small.

3. The patterns of the uptake of injected radioactive vitamin B12 by the totallygastrectomized patient were grossly similar to those observed in normal controls,except for possibly slightly faster absorption of the injected material from the siteof injection, and somewhat faster and larger accumulation, but also faster discharge of radioactivity from the liver area.

4. In a patient with pernicious anemia in partial remission who received threeparenteral doses of 2 respectively 10 µg. radioactive vitamin B12 (0.185-0.925µc. Co60), the uptake of the radioactive vitamin B12 by the kidney and spleen areawas slightly higher than that of the normal controls, that of the liver similar tothe normal, and that over the iliac crest showing a significantly faster declinethan in normals during the course of study. The uptake of radioactive vitamin B12in the same patient following intravenous injection of the same dose of radioactivevitamin B12 was grossly similar to that following intramuscular injection of thesame dose of radioactive material, except for the faster accumulation of radioactivity over the kidney area.

5. From 65 to 86 per cent of the peak radioactivity persisted over the liver 2-3months after parenteral administration of radioactive vitamin B12 to two controlsubjects. After five months 60 per cent of the initial peak of radioactivity wasstill observed over the liver in the patient with anemia of sprue in remission, 85per cent in a patient with pernicious anemia in partial remission, and at the endof eight months still 35 per cent of the peak liver count in a patient with total gastrectomy without anemia. This does not take into account the normal decay ofCo60 which is about 1 per cent per month.

6. If the presence of Co60 in the liver indicates the deposition of Co60-B12 in thisorgan, which is most probable, then the long storage of vitamin B12 in the livermay explain the long time needed in humans for depletion of hepatic stores ofvitamin B12, as well as for long remissions observed in pernicious anemia followingparenteral treatment with liver extracts or vitamin B12.

Submitted on May 10, 1954 Accepted on July 21, 1954  相似文献   

4.
Lymphocyte subsets in the peripheral blood, liver and spleen of patients with idiopathic portal hypertension (IPH) were examined by means of flow cytometry and immunohistochemical analysis using monoclonal antibodies. The patients with IPH showed a slight decrease in the percentage of Leu2a+ cells and a slight increase of the ratio of Leu3a+ to Leu2a+ cells in the peripheral blood compared with the normal subjects. Flow cytometry analysis of the intrasplenic lymphocyte subsets in the patients with IPH revealed a significant elevation in the percentage of Leu2a+ cells (p less than 0.01) and a reduction of the Leu3a+ to Leu2a+ ratio (p less than 0.05) compared with the normal subjects, and also showed an increase in the percentage of Leu2a+ cells (p less than 0.05) in comparison to the patients with cirrhosis of the liver. An immunohistochemical and histometrical study of the spleen in the patients with IPH revealed an elevation of the amount of red pulp area compared to the normal subjects, and also a significantly increased number of Leu2a+ cells in the red pulp (p less than 0.02) in comparison to the patients with cirrhosis of the liver. Most of the Leu2a+ cells in the spleen were considered to be Leu2a+.15- cells by double immunostaining method. In lymphoid follicles, the IPH cases showed an increase in the size of follicle and germinal center, and an increased number of Leu3a+ cells in the germinal center and the marginal zone compared with the normal subjects. In the liver, the IPH cases showed a similar distribution but fewer lymphocyte subsets in comparison to the patients with cirrhosis of the liver. These results suggested that some immunological disorder is present in patients with IPH.  相似文献   

5.
Splenic Function in Adult Coeliac Disease   总被引:5,自引:0,他引:5  
S ummary . The rate of clearance of 15Cr-labelled, heat-damaged red cells from the circulation has been measured in 18 patients with adult coeliac disease. This has been combined with scintillation scanning of the spleen using a colour scanning method. Only two of the patients had clearance times within normal limits. Five had a peripheral blood picture suggestive of splenic atrophy. In these the half time of clearance was greater than 50 min and the scintillation scan showed either no evidence of functioning splenic tissue or only minimal localization of radioactivity suggesting marked hyposplenism. Nine patients had a somewhat prolonged clearance time, the half time of clearance varying between 19 and 44 min. The scan, however, showed an apparently normal spleen and the characteristic changes of splenic atrophy were not present in the peripheral blood film. Two patients had clearance rates faster than that found in control subjects. Both of these patients had enlarged spleens. In one this was associated with hepatic cirrhosis and in the other with an unexplained neutropenia.  相似文献   

6.
RIFKIND  RICHARD A. 《Blood》1965,26(4):433-448
This study reports electron microscope observations on the process of redcell sequestration and destruction in the spleen and liver of the phenylhydrazine-treated rabbit. Damaged red cells are recognized by virtue oftheir Heinz bodies, a morphologic manifestation of the oxidative injury whichthey have sustained. Sequestration, in the spleen, involves the selective accumulation of damaged cells within the vascular spaces of the Billroth cords.Erythrophagocytosis and the intracellular digestion of red cells followssequestration. More severely injured cells may undergo intravascular hemolysiswithin the splenic red pulp. In the liver, however, no evidence for the intravascular sequestration of injured red cells is observed. Damaged cells areremoved directly from the sinusoidal blood by erythrophagocytosis. Theselectivity of spleen and liver for red cells subjected to different degrees ofinjury is discussed in terms of the observed differences in the vasculararchitecture of the two organs.

Submitted on November 15, 1964 Accepted on November 22, 1964  相似文献   

7.
Ferritin concentration has been measured in peripheral blood mononuclear cells and in the incubation medium following in vitro culture. Antibodies to both heart and spleen ferritin were used. Mononuclear cells cultured in medium containing about 12 mumol Fe/l accumulate ferritin rapidly with an increase in the heart:spleen ferritin ratio from 3:1 to about 10:1. Higher concentrations of iron (100 mumol/l) produce an even greater effect. The accumulation of ferritin is prevented by the addition of desferrioxamine (2 mmol/l) to the incubation medium. Accumulation of ferritin appears to take place largely in monocytes. Phagocytosis of red blood cells also causes rapid accumulation of ferritin but without any change in the heart:spleen ratio. Small amounts of both spleen and heart type ferritin are released during incubation in an iron containing medium and following phagocytosis of red blood cells. Some concanavalin A binding ferritin is also released suggesting that phagocytic cells may be a source of the concanavalin A binding ferritin found in normal plasma.  相似文献   

8.
The Role of Ascorbic Acid in the Metabolism of Storage Iron   总被引:6,自引:0,他引:6  
S ummary . The role of ascorbic acid in the metabolism of storage iron was investigated in guinea-pigs. Ascorbic acid deprivation increased the total non-haem iron concentration in the spleen and reduced it in the liver, and in both organs ferritin was diminished and haemosiderin increased. Replacing the ascorbic acid restored the normal distribution of iron between the two storage compounds, and in the spleen the total storage iron concentration returned to control levels within 24 hr. Evidence was obtained in experiments with 59Fe that the accumulation of iron in the spleen was due to a diminished release from reticulo-endothelial cells. When 59Fe-labelled haemoglobin in denatured red cells was injected, release of the isotope was inhibited in scorbutic animals. In contrast, after injecting labelled transferrin, 59Fe in the liver parenchymal cells was released to a greater extent than in normals. These observations may explain certain ferrokinetic peculiarities in patients with scurvy, and possibly also the predominantly reticulo-endothelial localization of the iron in Bantu subjects with siderosis.  相似文献   

9.
The distribution within the body of autologous leukemic cells labeled with indium-111 oxine was studied in seven patients with acute nonlymphocytic leukemia. The leukemic blood cells initially entered the spleen and liver, and the major site of localization was the former rather than the latter. The majority of the leukemic cells had not left the spleen and liver within 48 hr. Liver radioactivity fell transitorily up to the third hr after the initial rise. The clearance curve of radioactivity from the blood showed a plateau or the appearance of a “hump” from 1 to 5 hr after injection of labeled leukemic cells. These results might reflect recirculation of a portion of the leukemic cells between these organs and the bloodstream. In a patient with acute monoblastic leukemia, OKMl monoclonal-antibody-treated monoblasts showed the lowest recovery into the blood and a greater increase of liver than splenic radioactivity at 30 min after injection. These results suggest the removal of damaged cells by the cytotoxic effects of antibody mediated by reticuloendothelial clearance mainly of the liver and others. In one patient with acute promyelocytic leukemia, leukemic cells accumulated in both kidneys, indicating the possible infiltration of these cells. Since indium-111 oxine stays firmly attached to the cells in spite of the possibility of radiation damaged in a long-term survey, it seems an ideal label for studying leukemic cell kinetics.  相似文献   

10.
Summary Attempts were made at the experimental elimination of the sequestration function of the spleen on Wistar rats using ethyl palmitate (EP). Following an i. v. injection of EP emulsion in an amount of 0.35 g and 0.10 g/ 100 g of body weight the clearance of51Cr-labeled and heat-damaged red cells from the blood and their sequestration in the spleen and liver at 24-h, 3-, 10-, 20-, and 50-day intervals was examined. A high dose of EP caused, notably at 24 h and also after 3- and 10-day intervals, a significant decrease of radioactivity in the spleen and considerably prolonged the clearance time of the red0 cells. The extent of changes were comparable to those of surgical splenectomy. At later intervals (20 and 50 days after EP injection) some animals showed partial regeneration of the sequestration ability of the spleen; in some other animals the splenic damage was permanent. Changes induced by small doses of EP were less pronounced and of transient character.
Abbreviations EP ethyl palmitate - S.D. standard deviation  相似文献   

11.
Red cell survival, surface counting indices, the splenic and hepatic contribution to red cell destruction and the rate of splenic and hepatic red cell destruction were measured in 29 patients. Splenectomy was performed in 14. No correlation could be found between the splenic excess count index and both the amount and rate of red cell destruction in the spleen, but the rate of splenic and hepatic red cell destruction was related to the rate of disappearance of red cells from the circulation. The mean fractions of red cell destruction in spleen and liver were 46.1%± 20.5 (SD) and 11.7%± 4.2 (SD) respectively. After splenectomy, the haematocrit returned to normal in all patients despite fractions of red cell destruction in the spleen not exceeding 60%. Although the measurements of the splenic red cell destruction rate and of the fraction of red cell destruction in the spleen provide more precise information on the role of the spleen in red cell destruction, their prognostic value in patients who underwent splenectomy was not obvious.  相似文献   

12.
In order to evaluate a method permitting quantitation of splenic red blood cell destruction, a model of erythrocyte destruction in enlarged spleens was created: Erythrocytes are destroyed in the splenic erythrocyte pool at a constant rate, producing in labelling studies hyperhaemolysis due to random destruction. A mathematical analysis of the model shows that the splenic destruction rate can be calculated with great accuracy from quantitation of the initial excess radioactivity, measured over the spleen during the first days after infusion of 51Cr-labelled autologous erythrocytes. 18 patients with splenomegaly (479–4700 g) were investigated. The splenic erythrocyte destruction rate was estimated to be between 0.5–4.4% of the total erythrocyte mass per day, increasing significantly with increasing splenic weight. The results indicate that erythrocyte destruction takes place almost exclusively in the enlarged spleen in cases of predominant splenomegaly without complicating immunohaemolysis.  相似文献   

13.
The kinetics of autologous granulocytes, separated from whole blood and labelled with 111In-tropolonate with continuous maintenance in plasma, have been studied in man, using a gamma camera and computer, with the aim of quantifying the distribution of the marginating granulocyte pool (MGP). We have used 3 approaches: dynamic gamma camera imaging immediately following i.v. injection of labelled cells, comparison of the activity signal from 111In-granulocytes with that from previously injected 111In-labelled red cells and absolute quantification of 111In present in liver, spleen and blood. Deconvolution analysis of the hepatic and peripheral blood time activity curves indicated that hepatic granulocyte transit time was 2.5 +/- SE 0.14 min. By comparison with 111In red cells, hepatic transit time was calculated to be 7.4 +/- SE 0.82 that of red cells, which, assuming an hepatic red cell content of 6% that of the total red cell mass, is equivalent to a transit time of 1.8 min. By comparison with 111In red cells, lung granulocyte transit time as a factor of red cel transit time was 5.4 +/- SE 0.7 at 5 min and 2.5 +/- SE 0.13 at 40 min after granulocyte injection. Using these kinetic data, in combination with previously published values for splenic granulocyte transit time, it was calculated that, 5 min after injection, the MGP accounted for 54% of the total blood granulocyte pool (TBGP), was 90% filled, and was distributed between spleen (19%), liver (26%), lung (33%) and the remainder of the body (22%). At 40 min, the MGP accounted for 60% of the TBGP, had equilibrated with the circulating granulocyte pool (CGP), and was distributed between the spleen, liver, lung and remainder of the body according to the following respective percentages: 35, 25, 10 and 30. The total granulocyte contents of the spleen and liver calculated on the basis of the kinetic data were 21% and 22% respectively and in broad agreement with the values, 34 and 23% respectively, calculated from quantitative scanning. It was concluded that about 70% of the body's MGP was present in the spleen, liver and lung. If the MGP is itself 60% of the TBGP then only about 18% of the TBGP marginates in extra-hepatosplenopulmonary sites.  相似文献   

14.
BACKGROUND: It is known that disseminated intravascular coagulation (DIC) may occur along with aortic aneurysms. To assess the localization of the active consumption site we performed 111In-oxine labeled platelet scintigraphy in patients with chronic aortic aneurysms. METHODS: Images were obtained using 111In-oxine labeled autologous platelets in 45 patients. Planar images were taken twice (at 4 and 48 hrs) after injection. A visual inspection of the radioactivity uptake and special analysis in regions of interest were performed. RESULTS: Thirty-five patients (78%) showed a focal accumulation of radioactivity in the aortic aneurysm. Six of 13 patients (46%) with dissecting aortic aneurysm, and 4 of 32 patients (12.5%) with true aneurysms were evaluated as negative uptake by scintigram (p < 0.05). The aneurysm/heart ratio was 0.85 +/- 0.16 (mean +/- SD) (4 hrs) and 1.09 +/- 0.15 (48 hrs) after injection; the aneurysm/liver ratio was 0.56 +/- 0.16 (4 hrs) and 0.38 +/- 0.09 (48 hrs); the aneurysm/spleen ratio was 0.39 +/- 0.07 (4 hrs) and 0.39 +/- 0.08 (48 hrs). CONCLUSIONS: When the probability of DIC is clinically high in patients with aortic aneurysms, 111In-oxine labeled platelet scintigraphy provides useful preoperative information regarding the location of the functionally active consumption focus.  相似文献   

15.
晚期血吸虫病患者肝脾Ⅰ、Ⅲ型胶原含量的变化   总被引:2,自引:0,他引:2       下载免费PDF全文
目的 研究晚期血吸虫病(晚血)患者肝、脾组织Ⅰ型胶原(CⅠ)和Ⅲ型胶原(CⅢ)的含量变化。 方法 对55例晚血患者肝活检标本和脾切除标本进行常规病理检查,肝、脾纤维化程度分期,经天狼猩红染色后,于偏光显微镜观察CⅠ、CⅢ分布情况。用图像分析仪计算CⅠ、CⅢ含量。5例正常肝、脾标本作对照。 结果 患者肝组织CⅠ、CⅢ含量明显增加(P<0.01),肝窦中也明显增加(P<0.01),CⅠ/CⅢ比值明显降低(P<0.01)。随着肝纤维化程度的升高,肝窦CⅠ、CⅢ含量呈下降趋势,CⅠ/CⅢ比值则呈上升趋势。脾索CⅠ、CⅢ含量明显增加,CⅠ/CⅢ比值降低(P值均<0.01)。随着脾纤维化程度的升高,CⅠ、CⅢ含量呈上升趋势,CⅠ/CⅢ比值则呈下降趋势。 结论 晚血患者肝、脾组织CⅠ、CⅢ含量增加,以CⅢ增幅较大  相似文献   

16.
Alloimmune feto-maternal destruction of blood cells is thought to be mediated by binding of alloantibodies to Fc receptors on effector cells. Blocking the antigen using inert antibodies might prolong cell survival. We have performed a "proof of principle" study in volunteers to measure the intravascular survival of autologous red cells coated with human recombinant IgG antibody containing a novel constant region, G1Deltanab, devoid of in vitro cytotoxic activity. RhD-positive red blood cells (RBCs), labeled with chromium-51 or technetium-99m, were separately coated to equal levels with wild-type IgG1 or G1Deltanab anti-D antibody (Fog-1). After re-injection, there was complete, irreversible clearance of IgG1-coated RBCs by 200 minutes, concomitant with appearance of radiolabel in plasma. Gamma camera imaging revealed accumulation in spleen and, at higher coating levels, in liver. In contrast, clearance of G1Deltanab-coated cells was slower, incomplete, and transient, with whole blood counts falling to 7% to 38% injected dose by about 200 minutes before increasing to 12% to 67% thereafter. There was no appearance of plasma radiolabel and no hepatic accumulation. These findings suggest that G1Deltanab-coated RBCs were not hemolysed but temporarily sequestered in the spleen and that our approach merits investigation in larger studies.  相似文献   

17.
A case of antibody formation in a patient with carcinoid syndrome is described. The patient was treated with octreotide in dosages up to 1 5 mg/day. Serum samples were analysed for the presence of octreotide antibodies before and after 20 months of octreotide treatment. In-vivo 111ln-octreotide scintigraphy was performed before and during therapy, and after antibodies had developed. Before treatment, no serum antibodies against octreotide were detected. After 20 months of treatment, they were detectable up to a 1:115 serum dilution. The serum binding of 125I-Tyr3-octreotide was blocked by adding excess unlabelled Tyr3-octreotide, indicating the presence of specific octreotide antibodies. Before treatment, a normal distribution of radioactivity in the spleen and kidneys, irregular uptake in the liver due to metastases, and a hot spot in the lower abdomen were found during 111ln-octreotide scintigraphy. After antibodies had developed, increased radioactivity over the heart and high background radioactivity in the abdomen with only faint visualization of the spleen, liver, and kidneys were found, indicating a prolonged presence of 111ln-octreotide in the blood resulting from its being bound to antibodies. Increased radioactivity was also seen at the injection sites of the drug in the upper legs. In-vitro incubation of biopsy tissue from this site with 125l-Tyr3-octreotide revealed diffuse guanosine triphosphate (GTP) independent specific binding, indicating non-G-protein linked binding of labelled octreotide. This report describes the characteristic abnormalities during in-vivo 111ln-octreotide scintigraphy in a patient with octreotide antibodies. These consisted of high back ground radioactivity due to prolonged circulation of antibody coupled 111ln-octreotide together with visualization of the injection sites, which most probably results from local accumulation of antibodies.  相似文献   

18.
Dolichol is a long-chain polyisoprenoid. No enzyme pathway for dolichol degradation was discovered. Dolichol accumulates in human and rodent tissues during ageing. Red blood cells contain a larger amount of dolichol and red blood cell life span is shorter in older rats. The effects of age and of the load of dolichol from red blood cell degradation on the ageing-associated accumulation of dolichol in spleen were studied in 2, 6, 12, 18 and 24 month-old male Sprague Dawley rats fed ad libitum (AL) or on an anti-ageing dietary regimen (EOD). Tissue dolichol was extracted and assayed by HPLC [J. Gerontol. 53A (1998) B87]. Levels of dolichol increased in spleen, liver, kidney and muscle in parallel fashion from the age of 2 to 12 months. Unexpectedly, spleen dolichol decreased in older rats whereas liver, kidney and muscle dolichol increased significantly. The effects of haemolysis on spleen dolichol were tested by the administration of phenylhydrazine. Results show that haemolysis does not increase, but rather decreases the levels of dolichol in erythroclastic organs. It is concluded that the levels of spleen dolichol may decrease in the absence of any known enzymatic degradative pathway if the spleen and its resident phagocytes are forced to cope with a higher number of red blood cells to be cleared. Free-radical mediated decomposition of dolichol by phagocytic cells during erythrophagocytosis might be involved in the process.  相似文献   

19.
In order to study the metabolism of high density lipoprotein (HDL)-carried sterol in the rat, human HDL was reconstituted with [14C]cholesterol and [3H]cholesteryl ester. After iv injection into immature PMSG-human CG primed rats pretreated with 4-aminopyrazolopyrimidine and aminoglutethimide, there was time-dependent accumulation of 3H and 14C in various organs which reached a maximum by 15-90 min. On a milligram wet weight basis, uptake of 3H and 14C was greatest in the adrenals, next in ovaries, followed by the liver, with little uptake by kidneys and spleen. On an organ basis, accumulation was greatest by the liver. At 15-45 min post injection, 60% of the 3H in the ovary was in free sterol, indicating hydrolysis of the accumulated cholesteryl esters, whereas 95% of the 3H in serum remained in sterol esters associated with HDL. Coadministration of excess unlabeled HDL, but not human low density lipoprotein, reduced accumulation of radioactivity by the ovaries and adrenals by 60%, indicating a specific and saturable uptake process. Granulosa cells cultured in lipoprotein-deficient medium with reconstituted HDL formed 3H- and 14C-labeled 20 alpha-hydroxypregn-4-en-3-one. Over a 24-h period, utilization of both [14C]cholesterol and [3H]cholesteryl ester was linear, but rates of utilization of the two sterol moieties were not parallel. There was preferential uptake and utilization of free sterol. A dose-response study demonstrated a Michaelis-Menten constant (Km) of 40-60 micrograms sterol/ml for both free and esterified cholesterol. Lysosomotropic agents (chloroquine and NH4Cl) had no effect on utilization of either free or esterified cholesterol for steroidogenesis but reduced degradation of 125I-labeled low density lipoprotein apoprotein. These findings lend further support to the concept of a distinct HDL pathway in steroidogenic cells of the rat, which involves 1) preferential uptake and utilization of free cholesterol from HDL and 2) does not require lysosomal activity.  相似文献   

20.
Abstract: In the present study, we investigated the role of the spleen in experimental hepatic ischemia/reperfusion in the rat. After a 90-min period of ischemia in the left and middle hepatic lobes, the ischemia was released and the liver was reperfused for up to 24 h. Plasma alanine aminotransferase reached a peak 3 h after the onset of reperfusion, and gradually decreased thereafter. A histological examination revealed evidence of hepatocellular necrosis and degeneration, especially 24 h after the onset of reperfusion. In addition, there was a noticeable accumulation of polymorphonuclear cells in the liver following ischemia/reperfusion. A splenectomy performed just prior to ischemia/reperfusion reduced both biochemical and histological hepatocellular injury. The number of polymorphonuclear cells in the liver following ischemia/reperfusion was significantly reduced in rats subjected to splenectomy, suggesting that the increase in polymorphonuclear cells may contribute to liver injury. The number of mononuclear cells also increased in the marginal zones of the spleen following ischemia/reperfusion, and appeared to be derived from the splenic monocyte/macrophage population, based on immunohistochemical studies. The spleen plays an important role in the pathogenesis of hepatic ischemia/reperfusion injury and the splenic monocyte/macrophage population contributes to liver damage.  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