Chest ACCP Education Calendar
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Guest Access | Sign In via User Name/Password
This Article
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Article Archive
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Yokoyama, A
Right arrow Articles by Yano, S
Right arrow Search for Related Content
PubMed
Right arrow Articles by Yokoyama, A
Right arrow Articles by Yano, S

Chest, Vol 98, 924-927, Copyright © 1990 by American College of Chest Physicians

ARTICLES

Inhibition of natural killer cell activity by oral administration of theophylline

A Yokoyama, N Yamashita, Y Mizushima and S Yano
First Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.

Asthmatic patients have a low incidence of malignancies, and this is possibly due to higher NK cell activity in this population. Because theophylline is used widely in this population, we evaluated the influence of theophylline on NK cell activity in vitro and in vivo. The NK cell activity was significantly inhibited by direct addition of concentrations of aminophylline that exceeded 5 x 10(-5) M. To test whether such an effect can be observed in vivo, we administered one sustained-release tablet of theophylline (400 to 500 mg twice daily) to five normal volunteers for seven days. Significant inhibition of NK activity was noted after administration (mean percentage of inhibition, 41.3 percent), but the serum concentrations observed gave a mean value of 2 x 10(-5) M, which was lower than that yielding the same degree of inhibition by direct addition in vitro (about 20 x 10(-5) M). These results suggest that long-term theophylline therapy may inhibit NK cell activity, and thus more information would be needed to determine the position of such therapy in the management of asthmatic patients.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1990 by the American College of Chest Physicians.