Biochemical characterization of reactive nitrogen species by eosinophil peroxidase in tyrosine nitration.

It is well known that eosinophils are involved in tyrosine nitration. In this study, we evaluated tyrosine nitration by rat eosinophils isolated from peritoneal fluid and constituent eosinophils in the stomach. Rat peritoneal eosinophils activated with 1 microM phorbol myristate acetate (PMA) and 50 microM NO2- showed immunostaining for nitrotyrosine only in smaller cells, despite the fact that eosinophils are capable of producing superoxide (O2*-) Free tyrosine nitrating capacity after incubation with PMA and NO2- was 4-fold higher in eosinophils than in neutrophils. Catalase and alpha- and gamma-tocopherol inhibited free tyrosine nitration by reactive nitrogen species from eosinophils but not that by peroxynitrite. Superoxide dismutase augmented free tyrosine nitration by activated eosinophils and peroxynitrite. The concentration of nitric oxide released from eosinophils was relatively low (0.32 microM/10(6) cells/h) and did not contribute to the formation of nitrotyrosine. On the other hand, most constituent eosinophils constituent in the rat stomach stimulated by PMA and NO2- showed tyrosine nitration capacity. These results suggest that intact cells other than apoptotic-like eosinophils eluted in the intraperitoneal cavity could not generate reactive species responsible for nitration by a peroxidase-dependent mechanism. In contrast, normal eosinophils in the stomach were capable of nitration, suggesting that the characteristics of eosinophils in gastric mucosa are different from those eluted in the peritoneal cavity.

Practicality of Veterans Specific Activity Questionnaire in evaluation of exercise capacity of community-dwelling Japanese elderly.

OBJECTIVE: The aim of this study is to determine whether a questionnaire-based method using the Veterans Specific Activity Questionnaire (VSAQ) is a practical tool for the development of a safe exercise program to prevent a reduction in physical performance. METHODS: One hundred and twenty-one senior residents of Yakage, Okayama, agreed to voluntarily participate in this study. They were asked to complete a questionnaire for information on age, sex, subjective health status, exercise habits and VSAQ. We investigated the relationship between age and exercise capacity predicted by VSAQ (predicted metabolic equivalents (METs)). In addition, for 36 out of the 121 participants, we performed a 6-min walk distance test (6MD) and investigated whether its results correlate with the predicted METs. Furthermore, we prepared a modified VSAQ and examined its practicality in the evaluation of the exercise capacity of Japanese elderly (n=50). RESULTS: We found that the predicted METs correlate well with age. Habitual exercise and subjective health status did not affect the predicted METs. A significant correlation was observed between the predicted METs and the results of 6MD (r=0.56, p<0.001). We also found that certain activities included in the original VSAQ are unfamiliar to Japanese elderly; thus, we made a few modifications to the original VSAQ in order to evaluate the physical fitness of Japanese elderly. The number of inadequate answers was reduced by employing the modified VSAQ. CONCLUSION: These findings imply that the modified VSAQ is useful in evaluating the exercise capacity of Japanese elderly adequately and is a practical scale for safe exercise.