Abstract

Glucocorticoid can induce apoptosis of thymocytes, but its mechanism is not clear yet. In this study, we reported that dexamethasone-induced apoptosis was associated with intracellular alkalinization. Dexamethasone induced a higher percentage of apoptosis in 138 mM than in 50 mM NaCl, total abrogation of apoptosis was noted in NaCl-depleted culture medium. Highest apoptotic rate was observed in medium with pH 7.2, whereas it was partially and completely inhibited at pH 6.5 and pH 6.0, respectively. Intracellular pH was higher in pre-apoptotic thymocytes than non-apoptotic ones. The Na+/H+ antiporter inhibitor of 5-(N,N'-dimethyl)-amiloride inhibited the dexamethasone-induced increase in pHi and apoptosis of thymocytes. Glucocorticoid antagonist RU486 also blocked the dexamethasone-induced effect. Furthermore, the apoptosis and increase in intracellular pH induced by dexamethasone were inhibited by cycloheximide, actinomycin D. It seems that intracellular pH is increased during the development of thymocyte apoptosis and inhibiting its increment would retard the rate of progression to cell death.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.