Objective: To compare fasting total plasma homocysteine (tHcy) levels in vegans, lacto-ovovegetarians and control subjects, and to evaluate the relationships between tHcy levels and nutritional variables in vegetarians. Methods: The study was conducted on 45 vegetarian subjects: 31 vegans (19 males, 12 females, mean age 45.8 ± 15.8 years); 14 lacto-ovovegetarians (6 males, 8 females, mean age 48.5 ± 14.5 years), and 29 control subjects (19 males, 10 females, mean age 43.4 ± 16.7 years). tHcy was evaluated by high-performance liquid chromatography. Serum vitamin B₁₂ and folate were analyzed by automated chemiluminescence systems. Clinical records, nutritional and anthropometric variables were collected for all vegetarian subjects. Results: tHcy was significantly higher in vegetarian subjects than in controls (23.9 ± 21.3 vs. 11.6 ± 4.9 µmol/l, p < 0.001). The prevalence of hyperhomocysteinemia was higher in vegetarians than in controls (53.3 vs. 10.3%, p < 0.001). Serum vitamin B₁₂ levels were lower in vegetarians than in control subjects (171.2 ± 73.6 vs. 265.0 ± 52.2 pmol/l, p < 0.01; normal range 220–740 pmol/l). In vegetarian subjects, significant inverse correlations were found between tHcy and serum vitamin B₁₂ levels (r = –0.776, p < 0.001) and between tHcy and serum folate levels (r = –0.340, p < 0.05). Positive correlations were found between tHcy and mean red cell volume (r = 0.44, p < 0.01) and between tHcy and fat-free mass (r = 0.36, p < 0.05). Conclusion: Vegetarian subjects presented significantly higher tHcy levels, higher prevalence of hyperhomocysteinemia, and lower serum vitamin B₁₂ levels than controls.

Neutrophils play an important role in the immune system, forming the "first line of defence" against invading microorganisms and there are few data available concerning neutrophil functions in relation to exercise. We investigated in 7 basketball professional players possible changes before, during and after the sports season, in some haematological parameters and in several aspects of the phagocytic process of neutrophils, such as adhesion, superoxide anion release and bactericidal activity. Training and competitions produced a significant rise in the number of total leukocytes and differential counts, but the values returned to the pre-start levels 3 weeks after the end of the championship. The bactericidal activity and the superoxide anion released were significantly greater during the sports season, while the percentage of cellular adhesion significantly decreased during the championship; after the sports season the values returned to the control levels. As in the literature data concerning neutrophil functions in relation to exercise are non-convergent, it is important in our opinion, to understand whether the alterations induced by exercise can persist after repeated stimuli.

No abstract

In this work we studied the influence of an acute exercise either on nitrite/nitrate plasma levels or on neutrophil and platelet adhesion in inactive and active subjects. Twelve healthy subjects (6 inactives and 6 actives) exercised on a racing cycle ergometer performing stepwise increases in intensity until reaching, within 5 min, a heart rate of 150 beats x min(-1) which represents an oxygen consumption of about 75 % of the individual maximum rate of oxygen uptake. From peripheral venous blood samples (drawn from all subjects before, immediately after the end of exercise, and 1 hour later) neutrophils and platelets were isolated to test plate adhesion, and nitrite/nitrate concentrations were measured in the plasma. Immediately after the acute exercise, in active subjects we observed a significant decrease in the percentage of neutrophil adhesion (7.96+/-2.38 vs. 14.10+/-3.14), associated with an increase in nitrite/nitrate plasma levels (81.38+/-10.76 vs. 41.08+/-8.13 micromol x l(-1)), restored by a 40 min pre-incubation with NG-nitro-L-arginine methyl ester (L-NAME). In unstimulated platelets we observed a significant lower percentage of platelet adhesion in active subjects compared to inactives after exercise. With thrombin or adenosine 5'-diphosphate as agonists platelet adhesion did not result significantly different in active subjects compared to inactives. In conclusion, our data show that physical exercise can induce changes in some cell activities, even if transient, and favour the generation of nitric oxide. The lower adhesion of neutrophils and platelets induced by regular exercise could be an important goal in the prevention of vascular and inflammatory diseases.

Diclofenac and its derivative nitrofenac were compared to test their anti-inflammatory efficacy and gastrointestinal toxicity in rats. A similar good anti-inflammatory activity of the two drugs was observed in carrageenan oedema and a marked gastrointestinal toxicity was induced by diclofenac, while nitrofenac failed to produce gastric damage even with very high doses (50 and 100 mg/kg). The lack of the gastric ulcers in rats treated with nitrofenac could be due to the absorption of the drug as an inactive inhibitor of PG synthesis and/or to the fact that probably nitric oxide is released in the intestine and plays an important protective role in maintaining the tissue integrity.