The Vacuolar-TypeH+-ATPase in Ovine Rumen Epithelium is Regulated by Metabolic Signals

[摘要] In this study, the effect of metabolic inhibition (MI) by glucose substitution with 2-deoxyglucose (2-DOG) and/or application of antimycin A on ovine rumen epithelial cells (REC) vacuolar-typeH+-ATPase (vH+-ATPase) activity was investigated. Using fluorescent spectroscopy, basalpHiof REC was measured to be7.3±0.1inHCO3−-free, glucose-containing NaCl medium. MI induced a strongpHireduction (−0.44±0.04pH units) with a more pronounced effect of 2-DOG compared to antimycin A (−0.30±0.03versus−0.21±0.03pH units). Treatment with foliomycin, a specific vH+-ATPase inhibitor, decreased RECpHiby0.21±0.05pH units. After MI induction, this effect was nearly abolished (−0.03±0.02pH units). In addition, membrane-associated localization of vH+-ATPase B subunit disappeared. Metabolic control of vH+-ATPase involving regulation of its assembly state by elements of the glycolytic pathway could provide a means to adapt REC ATP consumption according to energy availability.

[学科分类] 基础医学