Biomedical subjects

C Barriga

Publications and source records attributed to C Barriga.

At least 37 records · Page 2Linked to original sources

PubMed1999

Correlation between the circadian rhythm of melatonin, phagocytosis, and superoxide anion levels in ring dove heterophils.

A functional role for melatonin is its relationship to circadian timing mechanisms. In addition, there has recently been assumed to be a functional connection between the pineal gland and the immune system in mammals and birds, with some findings showing melatonin to be a free radical scavenger and general antioxidant. The present study investigates the possible relationship between the circadian rhythm of melatonin and the ingestion capacity as well as superoxide anion levels of ring dove (Streptopelia risoria) heterophils. In birds, heterophils, with their ability to ingest and kill different antigens, play a central role in the host defence mechanism. All determinations were made during 24 hr periods at 2 hr intervals. Radioimmunoassay showed an increase of melatonin serum levels during the dark period (from 20:00 to 07:00 hr) with a maximum at 04:00 hr, and a significant decline during the hours of light with a minimum at 16:00 hr. Similarly, the phagocytic index was enhanced during the night, with the maximum at approximately 04:00 hr and the minimum at approximately 18:00 hr. The same was the case in relation to phagocytic percentage. However, the superoxide anion levels were lower during darkness (minimum at 04:00 hr) and higher during the light period (maximum at 14:00 hr). In conclusion, our findings show that one pineal-mediated effect on the immune system may be a direct action of melatonin on phagocytosis and the phagocytic biochemical process, and that this neurohormone might act as an antioxidant.

Animals↗

PubMed1998

Effect of polar glycopeptidolipids from Mycobacterium chelonae (GPLp-Mc) on phagocytosis and superoxide anion production of macrophages from mice. Influence of physical activity.

It is not clear how macrophages respond to exercise when the immune system is previously activated. The aim of the present work was to determine the response of macrophages to exercise in already immunostimulated animals with polar glycopeptidolipids extracted from Mycobacterium chelonae (GPLp-Mc). Results showed an increased phagocytosis and O2- production in murine macrophages induced by the intraperitoneal administration of 25 mg/kg body weight of GPLp-Mc. In addition exercise stimulated phagocytic activity and decreased the O2- production of these cells. Unexpectedly, exercise did not potentiate the immunostimulatory effect of GPLp-Mc. However, we can conclude that the effect of exercise is not detrimental to immunostimulated animals.

Adjuvants, Immunologic↗

PubMed1998

Seasonal variation in haematological parameters in male and female Tinca tinca.

This study was designed to investigate any seasonal (spring, summer, autumn and winter) changes in haematological parameters in the blood of Tinca tinca measuring the number of red blood cells (RBC), haematocrit, white blood cells, and total plasma proteins. The results show significant changes in RBC and haematocrit in males comparing spring and summer with autumn and winter, whereas in females the RBC remained constant for all 4 seasons but the haematocrit decreased in autumn and winter compared to spring and summer. The white blood cells of male and female animals were significantly lower in spring and winter compared to summer and autumn. In male fish total protein contents significantly decreased in autumn and winter compared to spring and summer, whereas in females protein output significantly decreased in winter compared to the other seasons. The results indicate marked seasonal variation in the blood of male and female Tinca tinca. This variation may play a important protective role for the survival of the animals.

Animals↗

PubMed1998

Melatonin controls superoxide anion level: modulation of superoxide dismutase activity in ring dove heterophils.

The pineal gland and the immune system in mammals and birds are functionally connected, with some recent findings showing that melatonin, the major secretory product of the pineal gland in vertebrates, is a free-radical scavenger and general antioxidant. In birds, heterophils, with their ability to ingest and kill different antigens, play a central role in the host defense mechanism. This in vitro study investigated the possible antioxidant action of melatonin in heterophils isolated from adult male and female ring dove (Streptopelia risoria). The superoxide anion levels (O2-.) and the superoxide dismutase (SOD) activity were evaluated as indicators of the metabolic burst of heterophils after ingestion of inert particles (latex beads) at the basal time (0 min) and 15, 30, 45, and 60 min of incubation with 100 microM melatonin. The heterophil O2-. levels, measured by the nitroblue tetrazolium reduction test, were lower after incubation in the presence of melatonin at all the times studied, a time-dependent effect. Latex beads produced a significant increase in SOD activity, whereas there was a significant decrease in the presence of melatonin. In addition, when heterophils were incubated in the presence of both latex beads and melatonin, the indole appeared to annul the enhancement of SOD activity (U-525nm) produced by latex beads. In conclusion, our findings show that the neurohormone melatonin could be a useful antioxidant.

Animals↗

PubMed1997

Exercise-induced stimulation of murine macrophage chemotaxis: role of corticosterone and prolactin as mediators.

1. Exercise provokes changes in the immune system, including macrophage activity. Chemotaxis is a necessary function of macrophages if they are to reach the focus of infection and strenuous acute exercise may modulate chemotaxis. However, the precise mechanisms remain unknown. 2. Three experiments were performed in the present study. (1) The effect of strenuous acute exercise (swimming until exhaustion) on the chemotactic capacity of macrophages was evaluated. (2) Peritoneal macrophages from control mice were incubated with plasma from exercised mice or control (no exercise) mice. The differences in the resulting chemotactic capacity were measured. (3) Changes in the concentration of plasma corticosterone and prolactin after exercise were also measured, and the effect of incubation with the post-exercise levels of plasma corticosterone and prolactin on the chemotactic capacity of the peritoneal macrophages was then studied in vitro. 3. Exercise induced an increase in the macrophage chemotaxis index (103 +/- 8 vs. 47 +/- 11 in controls). Incubation with plasma from exercised mice led to an increased level of chemotaxis (68 +/- 18 vs. 40 +/- 6 with plasma from controls). Incubation with concentrations of corticosterone and prolactin similar to those observed in plasma immediately after exercise (corticosterone, 0.72 mumol l-1; prolactin, 88 pmol l-1) raised the chemotactic capacity with respect to that following incubation with the basal concentrations of the hormones in control animals (90 +/- 9 vs. 37 +/- 4 for corticosterone; 72 +/- 9 vs. 41 +/- 4 for prolactin). 4. It is concluded that corticosterone and prolactin may mediate the increased chemotaxis of peritoneal macrophages induced by exercise.

Animals↗

PubMed1997

Melatonin and the phagocytic process of heterophils from the ring dove (Streptopelia risoria).

A functional connection between the pineal gland and the immune system in mammals and birds has been established. This study investigates the effect of melatonin upon the non-specific immunity of heterophils isolated from the ring dove. The different stages of the phagocytic process: adherence to nylon fiber, spontaneous and induced mobility, ingestion of latex beads and digestion were evaluated for heterophils incubated in the presence of 5, 25, 50, 75, or 100 microM of melatonin. In addition, the chemoattractant power of the hormone for heterophils was studied. The 100 microM melatonin dose possessed a significant chemoattractant ability for heterophils whilst ingestion of latex particles was enhanced at all doses studied. The superoxide anion level, as measured by the free radicals produced during the metabolic burst, is decreased after incubation with 100 microM of melatonin.

Animals↗

PubMed1997

[Wine and health. Epidemiological studies and possible mechanisms of the protective effects].

Epidemiological studies show that moderate alcohol consumption, particularly wine, is associated to a decreased risk of ischemic heart disease death. A series of in vitro observations also support this association. Low density lipoproteins (LDL) oxidation apparently plays a key pathogenic role. Wine contains compounds with antioxidant capacity that could account for its postulated stabilizing effect on LDL. Furthermore, in human volunteers wine increases plasma total antioxidant capacity. Other additional effects also contribute to decrease the risk of ischemic heart disease: increased HDL cholesterol, and decreased blood coagulation. In another series of observations, moderate alcohol consumption has been associated with decreased physical and mental deterioration in elderly people. However, it is still under analysis if exaggerated alcohol consumption does increase the incidence of some cancers. On the whole, the presently available evidences clearly indicate that the positive effects associated to moderate wine or alcohol consumption, predominate over the negative effects. In fact, it seems reasonable to reassure moderate alcohol consumers that their cardiovascular death risk is lower; yet there are not enough studies to recommend moderate drinking to non-drinkers.

Adult↗

PubMed1996

Effect of prolactin on the in vitro phagocytic capacity of macrophages.

Prolactin (PRL) plays a modulatory role in immune function. Previous studies have demonstrated that physical activity (swimming until exhaustion) provokes a stimulation in the phagocytic function of peritoneal macrophages. In this study, we have investigated the possible role of PRL as a mediator of physical activity-induced stimulation of macrophage phagocytosis. Peritoneal macrophages from BALB/c mice were incubated for 30 min with 1.1 (basal concentration in these animals), 2.2 (the concentration observed in plasma after swimming until exhaustion) and 8, 16 and 22,000 ng/ml of PRL. The results indicated that incubation of peritoneal macrophages with a concentration of PRL similar to that observed in plasma immediately after physical activity stress stimulates phagocytic capacity. This stimulation was also observed after incubation of macrophages with the higher concentrations of PRL. We conclude that PRL may be considered as a mediator of physical activity-induced stimulation of macrophage phagocytosis, confirming the immunoregulatory role of this hormone.

Animals↗

PubMed1996

In vivo effect of teicoplanin and vancomycin upon haemolytic and bactericidal activity of serum against Staphylococcus aureus.

The present study was undertaken to determine whether teicoplanin and vancomycin influence the hemolytic and bactericidal activity of serum obtained from mice (Swiss, aged 15 +/- 2 weeks). Haemolytic activity was measured in CH-50 units (which represents the capacity of serum complement to lyse 50% of sheep red blood cells in the presence of specific antibody) and the bactericidal activity was estimated from the number of colony-forming units (CFU/ml) of Staphylococcus aureus that survived after 24 h of incubation in the presence of serum. The results indicate that (1) teicoplanin and vancomycin increase the haemolytic activity of serum; (2) in the serum from animals treated with both teicoplanin or vancomycin, the number of CFU/ml of Staphylococcus aureus declines; and (3) these antibiotics appear to have a similar effect upon the complement system.

Animals↗

PubMed1996

Effect of beta-endorphin on adherence, chemotaxis and phagocytosis of Candida Albicans by peritoneal macrophages.

There is growing evidence about the role of neuroendocrine hormones in the regulation of the immune system. In the present study we have examined effects on different stages of phagocytic function of peritoneal macrophages from BALB/c mice induced by beta-endorphin. Peritoneal macrophages were incubated (30 min at 37 degrees C) in vitro with 0.22, 0.5 or 2200 ng/ml of this hormone. Adherence capacity was evaluated by means of a substrate adherence technique, chemotaxis in Boyden chambers, and ingestion of Candida albicans on migration inhibitory factor (MIF) dishes. No changes in adherence capacity were found. Chemotaxis, however, increased, and concentration of beta-endorphin correlated directly with stimulation. Incubation of macrophages with 0.5 ng/ml of beta-endorphin also stimulated phagocytosis of Candida albicans. These results indicate that beta-endorphin acts on peritoneal marine macrophages, stimulating some stages of their phagocytic function.

Animals↗

PubMed1996

Corticosterone, prolactin and thyroid hormones as hormonal mediators of the stimulated phagocytic capacity of peritoneal macrophages after high-intensity exercise.

The aim of this study was to evaluate the effect of high-intensity physical activity (swimming until exhaustion) with or without previous training on the phagocytosis and destruction of inert particle capacities of macrophages, and the role of corticosterone, prolactin and thyroid hormones as possible hormonal mediators. The results indicated that high-intensity exercise provokes a stimulation of both phagocytosis and destruction of inert particles when performed in absence of previous training. However, swimming until exhaustion after a one month training program (25 min/day) induced an increase in phagocytosis but not in the destruction of latex beads. Corticosterone, prolactin and thyroid hormones can be considered as hormonal mediators of the exercise-induced stimulation of phagocytosis, since these hormones increased plasma concentration, and the in vitro incubation of macrophages with the same higher physiological plasma concentrations of each hormone, as after exercise, also induced phagocytic stimulation of these cells.

Animals↗

PubMed1996

Exercise-induced stimulation of murine macrophage phagocytosis may be mediated by thyroxine.

The present study was designed to test the hypothesis that changes in plasma concentrations of hormones may be responsible for the exercise-induced macrophage phagocytic stimulation. The effect of 30-min incubation of macrophages with plasma from mice previously exposed to swimming until exhaustion (with or without previous training) was studied, and the results showed a similar stimulation of the phagocytic capacity (attachment and ingestion) of these cells to that found in previous studies after exercise. Also, changes in plasma concentration of both thyroxine (T4) and 3,3',5-triiodo-L-thyronine (T3) after exercise were measured, and their effect on phagocytic capacity after in vitro incubation with peritoneal macrophages was investigated. Results indicated that, after exercise, plasma concentrations of T3 and T4 increased. Incubation of peritoneal macrophages for 30 min with a concentration of T3 similar to that observed in the plasma immediately after exercise (1.5 ng/ml) induced no modifications in the phagocytic capacity. However, a physiological concentration of T4 after exercise (75 ng/ml) stimulated the phagocytic capacity of peritoneal macrophages. In addition, a 10,000-fold greater concentration of these thyroid hormones did not modify the macrophage function. It is concluded that physiological concentration of T4 may be a mediator of the stimulation of the phagocytic function in macrophages induced by exercise.

Animals↗

PubMed1996

Comparative study of the effect of teicoplanin and vancomycin upon the phagocytic process of peritoneal macrophages.

The effect of Teicoplanin and Vancomycin upon the phagocytic process was compared by evaluating the different activities of the peritoneal macrophage phagocytic function from mice treated with these antibiotics. The results indicated that teicoplanin and vancomycin increased both the substrate adherence and chemotaxis of peritoneal macrophages and that neither antibiotic, at the concentrations of 10, 25, 50, 75 and 100 mg/l, had any chemoattractant capacity for peritoneal macrophages. There was an increase in the attachment of Candida albicans only in the macrophages from mice treated with vancomycin. The phagocytosis of C. albicans, Staphylococcus aureus, Escherichia coli and inert particles as well, as the nitroblue tetrazolium reduction capacity (microbicide capacity) increased in the presence of both antibiotics. The C. albicans digestion capacity increased only in the peritoneal macrophages from mice treated with teicoplanin.

Animals↗

PubMed1996

[Effect of pregnancy and lactation on the nutritional status of essential fatty acids in rat].

BACKGROUND: Pregnancy and lactation could be high risk situations for the development of essential fatty acid deficiencies. AIM: To study the effect of pregnancy and lactation on red blood cell phospholipids percentual fatty acid composition of virgin, pregnant and lactating rats. MATERIALS AND METHODS: Twenty four pregnant rats of 50 +/- 1 days of age were supplement with soy and 24 with fish oil during 21 days. Twelve rats of each group were sacrificed after 18 days of lactation, twenty four non pregnant rats received soy oil and acted as controls of pregnant and lactating rats. Red blood cell phospholipid fatty acid composition was analyzed by gas chromatography. RESULTS: The percentage of total omega-6 fatty acids of red blood cell phospholipid was 37.8 +/- 5.9, 32.6 +/- 0.6 and 38.3 +/- 3.5% in non pregnant, pregnant and lactating rats respectively (p < 0.001). The figures for total omega-3 fatty acids were 6.33 +/- 1.52, 4.31 +/- 0.39 and 2.7 +/- 0.46 respectively (p < 0.001). There was no change in eicosatrienoic fatty acid percentage. Supplementation with fish oil reverted the decrease in omega-6 and omega-3 fatty acid percentage of pregnant and lactating rats. CONCLUSIONS: Pregnancy and lactation decrease the capacity to transform precursors of essential fatty acids in long chain polyunsaturated fatty acids.

Animals↗

PubMed1995

A study of the role of corticosterone as a mediator in exercise-induced stimulation of murine macrophage phagocytosis.

1. It is generally accepted that physical activity provokes changes in the immune system. Previous studies have demonstrated that the stress of physical activity (swimming until exhaustion) increases the phagocytic activity of peritoneal macrophages. However, the precise mechanisms remain unknown. 2. Two experiments were performed in the present study. (A) Peritoneal macrophages from control mice were incubated with plasma from three different groups of mice: (1) mice subjected to swimming until exhaustion with no previous training, (2) mice subjected to the same activity but with 1 month of training (30 min day-1), and (3) a control (non-exercised) group. The differences in the resulting phagocytic (attachment and ingestion) capacity were measured. (B) Changes in the concentration of plasma corticosterone after exercise were also measured, and the effect of incubation with the postexercise plasma corticosterone level on the phagocytic activity of peritoneal macrophages was then studied in vitro. 3. The results were: (A) incubation with plasma from both groups of exercised mice (with and without previous training) led to increased levels of phagocytic capacity (number of C. albicans cells ingested per 100 macrophages). (B) Incubation with a corticosterone concentration of 0.72 mumol l-1 (similar to that observed in plasma immediately after exercise) raised the phagocytic capacity (144 +/- 12 after incubation with 0.72 mumol l-1 vs. 93 +/- 19 after incubation with 0.24 mumol l-1). This increase was also significantly greater than that observed with 7.2 mumol l-1 corticosterone. 4. It is concluded that corticosterone may mediate the increased phagocytic function of peritoneal macrophages induced by exercise.

Animals↗

PubMed1995

Effects of physical exercise and aging on ascorbic acid and superoxide anion levels in peritoneal macrophages from mice and guinea pigs.

The relationship of physical activity and aging, two processes with a high production of oxygen-free radicals to the ascorbate and superoxide anion (O2-) contents of peritoneal macrophages was studied in two animals species: guinea-pig (in which ascorbic acid is a vitamin) and mouse (in which ascorbic acid is not a vitamin). The effects of exhaustive exercise were examined in young and old animals. The results show that macrophages from old animals have a lower ascorbate content than those from young ones, whereas with exercise the ascorbate content increased in both old and young animals. This increase was higher in young than in old animals, and more evident in mice than in guinea-pigs. Aging also resulted in an increase in the O2- levels of macrophages. With exercise these levels decreased in young mice but increased in young guinea-pigs. In old animals the exhaustive exercise did not change the O2- levels. The results suggest in general a lack of correlation between the intracellular ascorbate and O2- levels in relation to both physical exercise and aging.

Aging↗

PubMed1995

Influence of the temperature upon the proliferative response of lymphocytes of tench (Tinca tinca) during winter and summer.

The influence of incubation temperature upon proliferation of Tinca tinca lymphocytes induced by phytohemagglutinin (PHA) and E. coli lipopolisaccharide (LPS) mitogens was studied during the summer and the winter. The cultures were performed in vitro at 22 degrees C in both summer and winter, and at 12 and 30 degrees C in winter and summer respectively. The proliferative response at 22 degrees C was higher than that at 12 degrees C during the winter, and a small increase was observed at 30 degrees C respective to 22 degrees C in summer. These results indicate that in vitro lymphocyte proliferation requires temperatures higher than those in the fish environment.

Animals↗

PubMed1995

Seasonal variations in the immune system of the cyprinid Tinca tinca. Phagocytic function.

Seasonal variations in the in vitro phagocytic process of blood granulocytes from the tench Tinca tinca were examined. Different stages of the phagocytic process: mobility rate, attachment, ingestion and killing of Candida albicans were evaluated. Tench were kept in natural ponds in ambient water temperature, and the in vitro assays were performed at both 22 degrees C and the relative ambient temperature. Results between the seasonal samples were then compared. In vitro induced mobility, attachment, ingestion and killing of C. albicans showed strong seasonal variations, furthermore, the phagocytic process at 22 degrees C varied significantly according to season. Phagocytic activity from samples taken during the spring demonstrated the highest activity at 22 degrees C, whilst greatest activity at seasonal temperature, in terms of mobility rate, phagocytic index and microbicide capacity, occurred during the winter. These results are consistent with the hypothesis that phagocytosis in fish is resistant to low temperatures.

Animals↗