Phagocytic Ability Of Macrophages Research Articles

Estudo de biocompatibilidade in vivo e in vitro do extrato hidroalcoólico de Cissus sicyoides L. - Vitaceae em ratos

Biocompatibilidade é a capacidade de um material exercer funções específicas quando aplicado em contato com tecidos vivos de determinado hospedeiro, sem, contudo, causar danos ou prejuízo ao mesmo. Este trabalho objetivou determinar a biocompatibilidade in vivo e in vitro do extrato hidroalcoólico do Cissus sicyoides L - Vitaceae. Foram utilizados 30 ratos (Rattus novergicus albinus wistar), com idade entre 45 e 90 dias e pesando entre 170 e 260 g. Os animais foram divididos em 3 grupos (A1, A2 e A3) de 6 animais cada para o teste in vivo, os quais foram sacrificados com 2, 4 e 6 dias, respectivamente. Para o teste in vitro, foram utilizados 12 animais para obtenção do índice de aderência e da capacidade fagocítica dos macrófagos de ratos do grupo controle e do grupo experimental. Nos resultados encontrados no teste in vivo, conclui-se que o extrato apresentou-se biocompatível, visto que não provocou alterações significativas no tecido. Já no teste in vitro, o mesmo não se apresentou biocompatível, pois o extrato puro apresentou índice de aderência baixo (7,1) e taxa de fagocitose elevada (35,7), indicando diferença significante quando comparado ao controle. Porém, quando diluído, o extrato se mostrou inócuo, devido ao aumento dos valores do índice de aderência nas concentrações de 1/10 (61,4) e 1/100 (74,3) nos ensaios, as quais não apresentaram diferença significante quando comparadas ao controle. Após a análise dos dados, concluiu-se que a solução diluída do extrato hidroalcoólico do Cissus sicyoides L. não causa danos ou prejuízos. Entretanto, como nem todos os efeitos farmacológicos foram testados no presente trabalho, não se pode inferir automaticamente que ele é biocompatível em todos os casos.

The Effect of Tempeh on the Ability of Macrophage Phagocytosis An experimental study in male Balb/c mice

Background: Consuming tempeh regularly increases the levels of isoflavones in the our body influencing the IFNã and macrophage activating factor (MAF) that lead to the in increase in the ability of macrophage phagocytosis. Macrophage phagocytosis gives an illustration of the macrophages ability as the first line of phagocytic cells to digest foreign particles. This study aims at finding out the influence of tempeh on the ability of macrophage phagocytosis.Design and Methods: In an experimental study using post test only control group design, 15 mice Balb/c were divided into 3 groups of 5 mice each. Gp1: 0.5 gr of tempeh juice, Gp2: 1 mg tablet imboost in 1 cc of water (positive control), Gp3: 1 cc of 1 times (negative control). Treatment was given daily for 12 days. On day 13, Phagocytic ability of macrophages were examined using latex beads method. Data were analyzed using one Kruskal Wallis test followed by Independent T-Test.Results: The phagocytic ability for the three groups were 760,6 -----± 109,898 ; 244.2 ± 70.159; 9.6 ± 2.839 respectively. Independent t- test resulted in the significance difference (p = 0.008) between treated groups and control groups, both positive and negative ones (p<0,05).Conclusion: There is a difference in phagocytic ability between treatment and control groups (Sains Medika, 3(1):54-62).

Chronic morphine modulates actin polymerization leading to inhibition of Fc-gamma receptor mediated phagocytosis (111.29)

Abstract Morphine has been known to modulate innate immune functions, by inhibiting macrophage phagocytosis. However, mechanisms by which morphine inhibits macrophage phagocytic ability remain to be explained. Our results indicate that chronic morphine treatment in vitro and in vivo inhibited Fcγ receptor mediated phagocytosis in murine macrophages by inhibiting actin polymerization. Using fluorescence microscopy and fluorometry, we showed that chronic morphine treatment led to inhibition of actin polymerization resulting in impaired internalization of opsonized dextran beads. Chronic morphine treatment inhibited activation of Rac1-GTPase, therefore inhibiting formation of lamellipodia and membrane ruffling. Morphine’s inhibition of Rac1-GTPase activation was abolished in J774 macrophages transfected with constitutively active Rac1. In addition, chronic morphine treatment led to an increase in intracellular cAMP, which resulted in inhibition of actin polymerization through a PKA dependant pathway. DB-cAMP, by increasing intracellular cAMP, led to suppression of actin polymerization while H89 treatment induced inhibition of PKA and abolished morphine’s inhibitory effect implicating cAMP as the key effector in morphine’s modulation of actin. Together these data indicate that chronic morphine by increasing cAMP, activating PKA which inhibits Rac1 GTP-ase, leads to inhibition of actin polymerization and phagocytosis.

Hydrogen peroxide enhances phagocytosis of Pseudomonas aeruginosa in hyperoxia

Mechanical ventilation with hyperoxia is a necessary treatment for patients with respiratory distress. However, patients on mechanical ventilation have increased susceptibility to infection. Studies including ours have shown that reactive oxygen species (ROS), generated by exposure to prolonged hyperoxia, can cause a decrease in the phagocytic activity of alveolar macrophages. Hydrogen peroxide (H2O2) is a form of ROS generated under hyperoxic conditions. In this study, we examined whether treatment with H2O2 directly affects macrophage phagocytic ability in RAW 264.7 cells that were exposed to either 21% O2 (room air) or 95% O2 (hyperoxia). Moderate concentrations (ranging from 10 to 250 µM) of H2O2 significantly enhanced macrophage phagocytic activity and restored hyperoxia-suppressed phagocytosis through attenuation of hyperoxia-induced disorganization of actin cytoskeleton and actin oxidation. These results indicate that H2O2 at low–moderate concentrations can be beneficial to host immune responses by improving macrophage phagocytic activity.

Effects of different levels of vitamin E on growth performance and immune responses of broilers under heat stress

This experiment was undertaken to evaluate the effect of dietary vitamin E on growth performance and immune response of broilers under heat stress (HS). Birds raised in either a thermoneutral (23.9°C constant) or HS (23.9 to 38°C cycling) environment were fed a corn-soybean meal basal diet supplemented with vitamin E at 0, 100, or 200 mg/kg, respectively. Two hundred forty 1-d-old male broiler chicks were randomly assigned to 6 groups; each group had 4 replicates of 10 birds. Humoral immunity was assessed by i.v. injection of 7% SRBC followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by using a Sephadex stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. Body weight and feed intake were not significantly influenced by dietary vitamin E (P > 0.05), whereas feed conversion was significantly affected by vitamin E at 100 mg/kg (P < 0.05). Heat stress significantly reduced BW, feed intake, and feed conversion (P < 0.05). Numbers of AEC, percentage of macrophages in AEC, phagocytic macrophages, and internalized opsonized and unopsonized SRBC were increased by dietary vitamin E (P < 0.05). Both primary and secondary antibody responses were significantly increased by dietary vitamin E when birds were exposed to HS (P < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC, and phagocytic ability of macrophages were all significantly reduced under HS. These results indicated that HS severely reduced growth performance and immune response of broilers, whereas the immune response of broilers could be improved by dietary vitamin E supplementation under HS.

Effects of different levels of selenium on growth performance and immunocompetence of broilers under heat stress

An experiment was undertaken to evaluate the effect of dietary selenium (Se) levels on growth performance and immune competence of broilers under heat stress. Birds were raised in either a thermoneutral (TN, 23.9°C constant) or heat stress conditions (HS, 23.9°C to 38°C cycling) and were fed a corn-soybean meal basal diet supplemented with Se at 0, 0.2 and 0.4 mg/kg. A total of 240 one-day-old male broiler chicks were randomly assigned to six groups; each group had four replicates of 10 birds. Body weight and feed intake were not influenced by dietary Se, while feed conversion was significantly improved by a Se-supplementation of 0.2 mg/kg. HS significantly reduced body weight, feed intake and feed conversion. Numbers of abdominal exudate cells (AEC), percentage of macrophages in AEC, phagocytic macrophages, internalized opsonised and unopsonised sheep red blood cells (SRBC) were significantly increased by dietary Se. Both primary and secondary antibody responses were characterised by increasing titres of antibody to SRBC by dietary Se when birds were exposed to HS (p < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC, and phagocytic ability of macrophages were also significantly reduced under HS. These results indicated that HS severely reduced growth performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary Se supplementation under HS.

Dietary vitamin A can improve immune function in heat-stressed broilers

This experiment was undertaken to evaluate the effect of dietary vitamin A on the performance and immune competence of broilers under heat stress (HS). A total of 180 birds, at 22 days of age, were randomly assigned to be reared either at 24°C (thermoneutral, TN, 24°C, constant) or 24°C to 38°C (heat stress, HS, cycling) until the age of 42 days. Birds were then supplemented with vitamin A at 750, 1500, 15 000 IU/kg. Each of the 2 × 3 factorially arranged treatments were replicated in six cages, each containing five birds. Humoral immunity was assessed by intravenous injection of 7% sheep red blood cells (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by using a Sephadax stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. Body weight (BW) and feed conversion were significantly affected by dietary vitamin A (P < 0.05). HS significantly reduced BW, feed intake and feed conversion (P < 0.05). Numbers of AEC, percentage of macrophages in AEC, phagocytic macrophages, internalized opsonized and unopsonized SRBC were increased by dietary vitamin A (P < 0.05). Both primary and secondary antibody responses were characterized by increasing titers of antibody to SRBC by dietary vitamin A when birds were exposed to HS (P < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC and phagocytic ability of macrophages were all significantly reduced under HS. These results indicated that HS severely reduced performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary vitamin A supplementation under HS.

Sex differences in the impact of ozone on survival and alveolar macrophage function of mice after Klebsiella pneumoniae infection

BackgroundSex differences have been described in a number of pulmonary diseases. However, the impact of ozone exposure followed by pneumonia infection on sex-related survival and macrophage function have not been reported. The purpose of this study was to determine whether ozone exposure differentially affects: 1) survival of male and female mice infected with Klebsiella pneumoniae, and 2) the phagocytic ability of macrophages from these mice.MethodsMale and female C57BL/6 mice were exposed to O3 or to filtered air (FA) (control) and then infected intratracheally with K. pneumoniae bacteria. Survival was monitored over a 14-day period, and the ability of alveolar macrophages to phagocytize the pathogen in vivo was investigated after 1 h.Results1) Both male and female mice exposed to O3 are significantly more susceptible to K. pneumoniae infection than mice treated with FA; 2) although females appeared to be more resistant to K. pneumoniae than males, O3 exposure significantly increased the susceptibility of females to K. pneumoniae infection to a greater degree than males; 3) alveolar macrophages from O3-exposed male and female mice have impaired phagocytic ability compared to macrophages from FA-exposed mice; and 4) the O3-dependent reduction in phagocytic ability is greater in female mice.ConclusionO3 exposure reduces the ability of mice to survive K. pneumoniae infection and the reduced phagocytic ability of alveolar macrophages may be one of the contributing factors. Both events are significantly more pronounced in female mice following exposure to the environmental pollutant, ozone.

Reduced alveolar macrophage migration induced by acute ambient particle (PM10) exposure

Increased levels of particulate air pollution (PM10) have been implicated as a causal agent in pulmonary disease exacerbation and increased deaths from respiratory and cardiovascular disorders. The exact mechanism by which PM10 drives toxicity in the lung is still unknown, but studies have focused on inhibition of macrophage function and impaired alveolar clearance mechanisms. To assess the effects of PM10 on pulmonary macrophage clearance mechanisms ex vivo, Wistar rats were instilled with 125 or 250 microg of PM10 collected from the North Kensington, London. Control rats were instilled with sterile saline. The rats were sacrificed after 18 h and a bronchoalveolar lavage (BAL) was performed. Macrophages isolated from the BAL fluid were assessed for ability to migrate towards a positive chemoattractant (ZAS) ex vivo and to perform phagocytosis. Macrophages isolated from the PM10-exposed rats showed inhibition of potential to migrate. Macrophage phagocytic ability ex vivo was also significantly reduced by the presence of PM10 inside the cells. This study indicates that acute PM10 exposure diminishes macrophage motility and phagocytosis in a manner that could prove deleterious to particle clearance from the alveolar region of the lung. Decreased particle clearance promotes inflammation, and hence, warrants further investigation in relation to the effects of chronic PM10 exposure on macrophage clearance mechanisms and establishing the mechanisms behind decreased macrophage migration.

Frequent respiratory tract infections in the canine model of X-linked ectodermal dysplasia are not caused by an immune deficiency

As in many human patients with X-linked hypohidrotic ectodermal dysplasia (XHED), XHED dogs are at an increased risk for pulmonary disorders. Localized immune system defects had been suspected previously in affected dogs because of frequent infections and unexpected deaths due to opportunistic respiratory tract infections. Experiments were designed to examine systemic and localized humoral and cellular responses, development and function of T cells, and thymic morphology. All dogs used in these experiments were clinically healthy at the time of examination and their immune responses were compared to normal littermates. Serum immunoglobulin concentrations differed somewhat between normal dogs and dogs affected with XHED but they were all within normal ranges. The XHED dogs responded appropriately to vaccination with tetanus toxoid suggesting normal systemic B and plasma cell function. Thymic morphology was compared between normal and affected dogs and T cells were assessed for functionality. Numbers and phenotypes of T and B cells in blood and thymus of affected dogs were within normal limits suggesting normal development of T cells. Cytotoxic and phagocytic ability of macrophages and neutrophils was also normal in affected dogs. In contrast, the secretory IgA concentrations found in affected dogs were significantly higher than in normal dogs, while lacrimal secretions were significantly decreased. These results suggest a compensatory mechanism for secretory IgA, so that the total amount equals that in normal dogs. The results presented in this study indicate that the XHED dogs have a relatively intact immune system and suggest that the same is true for humans with the homologous form of XHED.

Effects of different levels of zinc on the performance and immunocompetence of broilers under heat stress

Male broilers were used to evaluate the effect of zinc on performance and immune competence during heat stress (HS). Broilers raised in either a thermoneutral (TN, 23.9 degrees C constant) or HS (23.9 to 35 degrees C cycling) environment were fed a low zinc diet (LZ; 34 mg/kg), an adequate zinc diet (AZ; 68 mg/kg), or a supplemental zinc diet (HZ; 181 mg/kg). Humoral immunity was assessed by intravenous injection of 7% SRBC followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed using a Sephadex stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. The HS birds consumed 12.5% less feed, gained 24.6% less weight, and had lower feed efficiency when compared to TN birds. Dietary zinc levels did not impact growth performance or plasma zinc concentration. Numbers of AEC, macrophages in AEC, phagocytic macrophages, and internalized opsonized and unopsonized SRBC were increased by HZ. Total, IgM, and IgG antibody titers for primary and secondary responses were significantly increased in birds receiving HZ under TN conditions. Tibia zinc concentration increased with increasing zinc levels but did not change with temperature. Lymphoid organ weights, primary and secondary antibody responses, incidences of macrophages in AEC, phagocytic ability of macrophages, and plasma zinc concentration were all significantly reduced by HS. These results indicate that the immune response of broilers can be influenced by the level of zinc in the diet and by environmental conditions.

Impairment of Alveolar Macrophage Phagocytosis by Ultrafine Particles

We investigated whether slowed clearance after exposure to ultrafine particles was due to a failure in alveolar macrophage phagocytosis. This was achieved by measuring the ability of a macrophage cell line (J774.2 MΦ) to phagocytose 2-μm indicator latex beads following 8-h exposures to a number of test particles. Particles utilized were fine titanium dioxide (TiO2), ultrafine titanium dioxide (UTiO2), carbon black (CB), or ultrafine carbon black (UCB). Cytotoxicity of particles was measured by means of MTT activity. In a preliminary study, we assessed the effects of conditioned medium from particle-treated macrophages on the phagocytic ability of naive macrophages. Ultrafine and fine particles had no significant cytotoxic effects on J774.2 MΦ. A significant reduction in the ability of macrophages to phagocytose the indicator beads occurred after exposure to 0.39 μg/mm2 (p < 0.001) of UCB and 0.78 μg/mm2 (p < 0.001) of all particle types compared to the control. Furthermore, ultrafine particles were shown to significantly (p < 0.001) impair macrophage phagocytosis at a lower dose than their fine counterparts (0.39 and 0.78 μg/mm2, respectively). At all doses, UCB resulted in a greater number (p < 0.001) of nonphagocytic macrophages compared to the other test particles. We tested whether a diffusable mediator being released from particle-exposed cells inhibited the phagocytic activity of adjacent macrophages. The conditioned medium from particle-exposed macrophages had no significant effect on the phagocytic ability of macrophages, suggesting that cell–cell contact is responsible for the pattern of failed phagocytosis (data not shown). We have demonstrated that ultrafine particles impair macrophage phagocytosis to a greater extent than fine particles compared on a mass basis. Therefore, we conclude that slowed clearance of particles, specifically the ultrafines, can in part be attributed to a particle-mediated impairment of macrophage phagocytosis.

Topical permethrin exposure inhibits antibody production and macrophage function in C57Bl/6N mice

Permethrin was applied to the shaved dorsal interscapular region of C57Bl/6N mice at doses of 0.5, 1.5 or 5.0 μl/day. These doses corresponded to approximately 22–220 mg/kg/day topical insecticide. Mice were exposed to permethrin in this manner daily for 10 or 30 consecutive days, or every other day for 7 or 14 exposures. The splenic macrophage chemiluminescent response was depressed in a dose-dependent manner at 2 and 10 days post-exposure to permethrin. Phagocytic ability of macrophages was not inhibited. Antibody production as shown by plaque-forming cell (PFC) assay decreased significantly after 10 consecutive days of exposure to permethrin. These data indicate that topical permethrin exposure may produce systemic immune effects.

Immunorestorative effect of glucan immunomodulator on guinea pigs with experimental ascariosis

The immunorestorative effect of glucan immunomodulator, combined with porcine immunoglobulin and zinc (GI) on T- and B-lymphocytes and peritoneal macrophage phagocytic ability was studied in guinea pigs with experimental ascariosis (Ascaris suum) after a cyclophosphamide (CY)-evoked immunosuppression. During the migration phase of A. suum infection GI exerted a significant restorative effect on the CY-reduced percentage occurrence of T- and B-cell populations in the mesenteric, mediastinal and hepatic lymph nodes and spleen of A. suum hosts. On the contrary, it did not influence the CY-suppressed phagocytic activity and index of phagocytic activity of the peritoneal macrophages. The protective effect of the GI evaluated by the reduction in the number of migrating ascarid larvae in the lungs of guinea pigs after immunosuppression with CY and administration of GI was 14.46% higher, compared with the suppressed and infected group without administration of GI.

Effects of heavy metals imission on the cellular immunity of guinea pigs with experimental ascariosis

A study was performed on the short-term effects of industrial heavy metals imission (Hg, Cu, Pb, Zn), collected at 5 km from a mercury-producing plant, on T- and B-lymphocytes and peritoneal macrophages of guinea pigs with experimental ascariosis ( Ascaris suum). Administration of the imission for 5 days showed a significant decrease in T- and B-cell population and in macrophage phagocytic ability during the migration phase of Ascaris suum when compared with an infected but untreated group of animals. This was also manifested by an eight-fold increase in the density of migrating ascaris larvae in the lungs. Macrophage metabolic activity in animals given imission was significantly suppressed only until Day 7 post-infection. The most striking decrease in the immunological responses was observed in guinea pigs that were given imission but were not infected.

Performance and Immunity of Heat-Stressed Broilers Fed Vitamin- and Electrolyte-Supplemented Drinking Water

The efficacy of different vitamin and electrolyte treatments of drinking water for heat-stressed broilers was studied in two experiments. In Experiment 1, commercial broilers (50% male, 50% female, sexed), were subjected to four drinking water treatments: 1) unsupplemented water (control); 2) B-vitamins plus electrolytes (B+El); 3) vitamins A, D, and E, B-vitamins plus electrolytes (ADEB+El); and 4) vitamins A, D, and E and B-vitamins (ADEB). Each treatment group was replicated in eight pens containing 70 birds. All birds were provided ad libitum access to feed through to 43 days of age and subjected to the water treatment from 16 to 21 days and 38 to 43 days. The birds were exposed to the 35 C ambient temperature during the last 72 h of each period. Immune function was tested on the males in each pen while they received the water treatments from 24 to 34 days of age. In comparison with the control, feed conversion was improved 5.6% by ADEB+El and ADEB, and body weight gain was improved 6.7% by ADEB (P<.05). Total and IgG antibody response against SRBC after primary immunization was improved by B+El; whereas, B+El and ADEB treatments improved IgG after secondary immunization. The highest numbers of Sephadex-elicited peritoneal macrophages were found among ADEB-treated birds, but neither adherence nor phagocytic ability of macrophages from either group was affected. Natural killer cells from all except ADEB+El-treated birds exhibited comparably high tumoricidal activity. In Experiment 2, commercial male broilers were given either unsupplemented water or vitamin-supplemented water (ADEB treatment) at 22 to 30 days, 37 to 41 days, and 52 to 55 days. The birds were exposed to 35 C at 38 to 41 days and 53 to 55 days of age. The two water treatments were replicated in 16 pens of 40 birds. Vitamin treatment increased 1- to 63-day body weight gain and feed conversion by 3 and 5%, respectively (P<.1), and it reduced mortality related to heat stress by 63% (P<.05). Vitamin supplementation of drinking water is beneficial for heat-stressed broilers, but the benefit of electrolytes is questionable.

Cytotoxicity, uptake and dissolution of 241AmO2 particles in dog alveolar macrophages in vitro.

Because alveolar macrophages play a role in the pulmonary clearance of inhaled particles, experiments were conducted to investigate the toxicity of 241AmO2 particles to alveolar macrophages and the role of these macrophages in the dissolution of 241AmO2 particles. Beagle dog pulmonary alveolar macrophages obtained by bronchopulmonary lavage were exposed in vitro to selected concentrations of 241AmO2. Macrophage viability determined by trypan-blue dye exclusion technique and the ability of the alveolar macrophages to phagocytose opsonized sheep red blood cells were the measures of 241AmO2 toxicity. The uptake of 241AmO2 particles was studied as a function of time. In addition, the dissolution of 241AmO2 by macrophages was determined for periods up to 72 h. After 20 h exposure to concentrations of 241Am higher than 4.63 kBq/ml, the phagocytic ability of macrophages was reduced, whereas no significant change in cell viability was observed at this concentration. Significant cell killing occurred at concentrations higher than 18.5 kBq/ml. After 72 h in the cultures, 10% of the 241AmO2 was dissolved by the alveolar macrophages. These findings imply that the inhalation of radioactive particles such as 241AmO2 particles might cause a reduction in the alveolar macrophage population in the lungs. In addition, the dissolution of 241AmO2 particles by alveolar macrophages might play a role in the short-term pulmonary clearance of inhaled 241AmO2 particles in the beagle dog.

Immune response in mice infected with Candida albicans in the mycelial form.

The effect of the infection with the mycelial form of a Candida albicans strain (Mycology Dept.) upon the immune system in mice was studied. BALB/c mice were infected intraperitoneally in a single dose of a 3 x 10(6), 6 x 10(6) and 12 x 10(6) cell suspension of the strain. Macrophages's activity was studied the days 7, 14, 21, 28, 35, and 42 after inoculation, by the following assays: phagocytosis in vitro, mononucleated phagocytic system by the colloidal carbon clearance technique, the lymphocyte's activity by the direct plaque forming cells technique (PFC) and delayed hypersensitivity (DTH). Infection with the mycelial form did not affect the peritoneal macrophage's phagocytic ability, neither modified the delayed hypersensitivity to sheep red blood cells (SRBC). However, a slight and transient depression of the lymphocyte stimulation was found. Suppression of PFC to SRBC was high when a 12 x 10(6) cell suspension was used in contrast to the infection with blastospores. These results suggest that systemic infection by Candida albicans in its mycelial form do not induce a non specific immunosuppression.

Age-related and testosterone-induced changes in the frequency of chicken peritoneal .ALPHA.-naphthyl butyrate esterase-positive cells.

This paper describes the age-related and hormonal bursectomy-induced changes in the frequency of appearance of α-naphthyl butyrate esterase (ANAB)-positive cells in chicken peritoneum. The phagocytic ability of macrophages was determined with sensitized and non-sensitized sheep erythrocytes (SRBC).The increase in the number of ANAB-positive cells ranged from 65% at 1 week of age to 90% at 2 and 4 weeks of age in controls. With testosterone propionate (TP) treatment during embryonic development, 98% of the cells taken were positive for ANAB at 1 week of age.Some difference was found in the non-specific phagocytosis, but not in the specific phagocytosis, between macrophages harvested from the normal and TP-treated groups. TP treatment induced enhancement of the non-specific phagocytic activity of macrophages. No correlation was found in the present study between non-specific phagocytosis and the appearance of ANAB-positive cells.

Phagocytic and bactericidal properties of bovine macrophages from non-lactating mammary glands

Macrophages were isolated from the mammary glands of non-lactating (dry) cows and their ability to phagocytose and kill staphylococci in vitro assessed. Normal bovine serum enhanced the uptake of staphylococci and was required for optimal killing in the bactericidal test. Dry gland secretion interfered with uptake. Secretions taken progressively into the dry period became more inhibitory. The phagocytic ability of macrophages was significantly less than that of neutrophils present in the same gland preparation when tested in the presence of dry gland secretion. A marked variation in the antibacterial activity of macrophages from different cows was noted.