Relations between number and volume of erythrocytes and leukocytes in the human blood

Total concentration of erythrocytes and leukocytes, a relative contents of neutrophils, lymphocytes, monocytes, average volume of these types of cells, were determined in humans. Changes in the cell indices seem to be correlated and sex-dependent. Thus, erythrocytes and leukocytes are correlated in their contents and volume characteristics. A control mechanism seems to exist in humans, involving microcirculation in capillaries.     

Effect of retinoic acid on the aggregation of erythrocytes and leukocytes in the blood

Human and animal blood smear staining with PAPh has revealed mononuclear leukocyte-erythrocyte aggregates. Administration of retinoic acid increased concentration and dimensions of these aggregates and was followed by preferential accumulation of PAPh-negative osmotically unstable erythrocytes. Similar changes were detected in the blood samples of women engaged in the production of retinoic acid. Aggregate concentration showed positive correlation with erythrocyte sedimentation rate and no correlation with prothrombin time.     

Lysophosphatidylserine-dependent interaction between rat leukocytes and mast cells

The production of lysophosphatidylserine has been studied in a population of rat peritoneal cells; 67% polymorphonuclear and 33% mononuclear leukocytes. Pulse-chase experiments with L-[U-14C]serine reveal a net lysophosphatidylserine production of 0.33 nmol/mg protein in 2 h of incubation. The source of lysophosphatidylserine is probably the phosphatidylserine of cells damaged during the incubation, since plasma membrane fragments obtained from the leukocytes yield higher lysophosphatidylserine production (1.9 nmol/mg protein in 1 h of incubation). Both leukocytes and plasma membranes show phosphatidylserine splitting activity when tested with vesicles of this phospholipid. In the presence of albumin a fraction of produced lysophosphatidylserine is recovered in the incubation medium. Under these conditions efficient incorporation of lysoderivative into surrounding leukocytes and conversion to phosphatidylserine requires cell activation by tetradecanoylphorbol acetate. In agreement with radiochemical data it is found that a suspension of leukocytes elicits histamine release when rat peritoneal mast cells and nerve growth factor are subsequently added. This typical, lysophosphatidylserine-dependent mast cell response is retained when leukocyte plasma membranes substitute the whole cells. These results suggest that leukocyte lysis at sites of tissue injury results in the production of a sufficient amount of lysophosphatidylserine to reach and activate surrounding mast cells.     

Calcium transport in chicken leukocytes and erythrocytes

1. In the present study, Ca2+ uptake and Ca2(+)-ATPase activity of two different chicken leukocyte populations and erythrocytes isolated from 1- to 6-week-old chickens were determined. 2. The Ca2(+)-ATPase activity of the two leukocyte populations significantly increased at 3 weeks of age. Erythrocyte Ca2(+)-ATPase activity significantly increased at 2 weeks of age. 3. Calcium transport activities into the two leukocyte populations did not differ significantly with age.     

5-nucleotidase activity in rat leukocytes, erythrocytes and blood serum during radiation sickness

A study of 5-nucleotidase activity in the formed elements and blood serum of rats 1, 3, 7, 15 and 30 days after X-irradiation has demonstrated that it was increased in leukocytes at early times and inhibited at later times of the development of radiation sickness. In erythrocytes, inhibition of 5-nucleotidase activity was most pronounced on the 3d day. In blood serum, the enzyme activity was virtually invariable. The addition of ATP to the incubation medium normalized 5-nucleotidase activity.     

正常淋巴液与血液的流变性及成分比较

目的：观察大鼠正常肠淋巴液与血液流变性及成分的差别。方法：从45只雄性Wistar大鼠肠系膜淋巴管引流正常肠淋巴液,并记录其流量;同时留取正常颈总动脉血液。检测表观粘度、淋浆及血浆粘度,常规白细胞计数及分类;检测血浆及淋浆的各项生化指标以及蛋白电泳。结果：正常大鼠的肠淋巴流量为（0．68±0．37）ml／h;正常肠淋巴液中的白细胞总数与血液近似,但淋巴细胞数高于血液（P〈0．01）;淋巴液表观粘度、相对粘度及淋浆粘度均显著低于血液或血浆（P〈0．01）;淋浆中的Ca^2＋、BUN、Cre、CHO、HDL、AMY、AFu、C3、IgG、IgM、AIb、TP以及α1-G、β2-G及γ-G所占百分比均显著低于血浆,TG、TBA、CKMB、ADA、CO2-CP以及Alb、β1—G所占百分比均显著高于血浆（P〈0．05—0．01）。结论：肠淋巴途径在物质代谢过程中发挥着重要作用,淋巴液的低粘特征可能是小量淋巴液抗休克的作用机制之一。     

Shear rate and orientation of erythrocytes in pulmonary microvessels of bullfrogs

Wall shear rates in arterioles and capillaries in the surface of exposed bullfrog lung were estimated to be 436 and 975 sec-1, respectively, at the intra-lung pressure at which a maximum flow velocity was observed. These high shear rates will probably permit an orientation of erythrocytes in a high degree. An orientation of erythrocytes was confirmed at a wall shear rate smaller than 16 sec-1 by means of a microscope connected with a video camera system. Erythrocytes kept their long axis along the direction of the overall blood flow, even when the blood flow transiently stopped flowing during the diastolic phase. The orientation of erythrocytes in such a high degree will be effective to reduce the blood flow resistance in pulmonary microvessels.     

Free radical lipid oxidation affects cholesterol transfer between lipoproteins and erythrocytes

Human erythrocytes were incubated for 5 h at 37 degrees C with lipoproteins (LP), preliminary oxidized to different extent, as assessed by thiobarbituric acid (TBA) test. Cholesterol content in the cells was increased by 12-14% after incubation with low-density lipoproteins (LDL) along with augmentation of order parameter and rotational correlation time of spin-labeled stearic acids incorporated into membranes. If erythrocytes were incubated with oxidized LDL, containing 2.5-4 times more TBA-reactive material than native ones, cellular content of cholesterol was increased by 24-28%. In contrast, high-density lipoproteins (HDL2 and HDL3) removed cholesterol from cell membranes, when incubated with erythrocytes. This was followed by increased fluidity of membrane lipid phase as detected by the spin probe method. Oxidation of HDL2 and HDL3 decreased their ability to accept cholesterol from cell membranes. No detectable accumulation of TBA-reactive material was observed in the samples during the incubation. The antioxidant, butylated hydroxytoluene (BHT), in the concentration of 10(-5) M did not influence the cholesterol transfer between LP and erythrocytes. Hence, the effects of lipid peroxidation (LPO) on the cholesterol transfer seem to result from LP alterations by oxidation rather than from free radical reactions occurring during the incubation. By increasing cholesterol-donating ability of LDL and inhibition of cholesterol-accepting capacity of HDL lipid peroxidation in LP may activate cholesterol accumulation in blood vessel cells and thus contribute to atherosclerosis.     

p53 codon 72 genotype affects apoptosis by cytosine arabinoside in blood leukocytes

A wide difference in the susceptibility to undergo in vitro apoptosis exists among individuals, and this fact has potential implications in predicting the in vivo response to apoptotic agents, such as those employed in chemotherapy. In this report, we addressed the question whether the natural variability at p53 locus (the proline-arginine substitution at codon 72) affects the capacity of peripheral-blood mononuclear cells from healthy subjects to undergo in vitro apoptosis in response to the cytotoxic drug cytosine arabinoside. We found that cells from subjects carrying the arginine/arginine genotype undergo in vitro apoptosis at a higher extent in comparison to those from arginine/proline subjects. This finding suggests that naturally occurring genetic variability at p53 gene explains part of the inter-individual difference in the in vitro susceptibility to a chemotherapeutic drug, thus resulting as an eligible predictor marker of in vivo response to chemotherapy and its adverse effects.     

Selectin-dependent rolling and adhesion of leukocytes in nicotine-exposed microvessels of lung allografts

The interaction of circulating leukocytes with lung microvessels is a critical event in the recruitment of effector cells into the interstitial tissue during episodes of inflammation, including smoking-induced chronic airway disease. In the present study, murine lung tissue transplanted into a dorsal skinfold window chamber in nude mice was used as a model system to study nicotine-induced leukocyte trafficking in vivo. The revascularized lung microvessels were determined to be of pulmonary origin based on their ability to constrict in response to hypoxia. We demonstrated that nicotine significantly enhanced rolling and adhesion of leukocytes within lung microvessels comprising arterioles and postcapillary venules in a dose-dependent manner, but failed to induce leukocyte emigration. Nicotine-induced rolling and adhesion was significantly higher in venules than in arterioles. Treatment of mice with monoclonal antibodies (MAbs) against L-, E-, or P-selectin after exposure of lung allografts to nicotine resulted in variable but significant inhibition of nicotine-induced rolling, whereas nicotine-induced subsequent adhesion was inhibited by MAbs against L- and P-selectin but not E-selectin. Exposure of lung allografts to nicotine along with PD-98059, a mitogen-activated protein kinase (MAPK)-specific inhibitor, resulted in significant inhibition of nicotine-induced rolling and adhesion. In vitro, exposure of murine lung endothelial cells to nicotine resulted in increased phosphorylation of mitogen-activated/extracellular signal-regulated protein kinase 1/2, which could be blocked by PD-98059. Overall, these results suggest that nicotine-induced inflammation in the airways could potentially be due to MAPK-mediated, selectin-dependent leukocyte-endothelial cell interactions in the lung microcirculation.