Covi 2007 Physiol Biochem Zool

From Bioblast
Jump to navigation Jump to search
Publications in the MiPMap
Covi JA, Hand SC (2007) Energizing an invertebrate embryo: bafilomycin-dependent respiration and the metabolic cost of proton pumping by the V-ATPase. Physiol Biochem Zool 80:422-32.

» PMID: 17508337

Covi JA, Hand SC (2007) Physiol Biochem Zool

Abstract: We examine herein the contribution of V-ATPase activity to the energy budget of aerobically developing embryos of Artemia franciscana and discuss the results in the context of quiescence under anoxia. (31)P-NMR analysis indicates that intracellular pH and NTP levels are unaffected by acute incubation of dechorionated embryos with the V-ATPase inhibitor, bafilomycin A(1). Bafilomycin A(1) also has no significant effect on oxygen consumption by isolated mitochondria. Taken together, these data indicate that bafilomycin does not affect energy-producing pathways in the developing embryo. However, the V-ATPase inhibitor exhibits a concentration-dependent inhibition of oxygen consumption in aerobic embryos. A conservative analysis of respirometric data indicates that proton pumping by the V-ATPase, and processes immediately dependent on this activity, constitutes approximately 31% of the aerobic energy budget of the preemergent embryo. Given the complete absence of detectable Na(+)K(+)-ATPase activity during the first hours of aerobic development, it is plausible that the V-ATPase is performing a role in both the acidification of intracellular compartments and the energization of plasma membranes. Importantly, the high metabolic cost associated with maintaining these diverse proton gradients requires that V-ATPase activity be downregulated under anoxia in order to attain the almost complete metabolic depression observed in the quiescent embryo. Keywords: V-ATPase, bafilomycin, brine shrimp, anoxia, embryos

O2k-Network Lab: US LA Baton Rouge Hand SC

Labels: MiParea: Respiration, Comparative MiP;environmental MiP, Developmental biology 

Stress:Ischemia-reperfusion  Organism: Artemia, Crustaceans 

Preparation: Isolated mitochondria 

Regulation: pH 

HRR: Oxygraph-2k