English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We have analyzed the effects of different native membrane lipid composition on the thermodynamic properties of the Na + -K + -ATPase in different epithelia from the gilthead seabream  Sparus aurata . Thermodynamic parameters of activation for the Na + -K + -ATPase, as well as contents of lipid classes and fatty acids from polar lipids were determined for gill epithelia and enterocytes isolated from pyloric caeca, anterior intestine and posterior intestine. Arrhenius analyses of control animals revealed differences in thermal discontinuity values ( Td ) and activation energies determined at both sides of  Td  between intestinal and gill epithelia. Eyring plots disclosed important differences in enthalpy of activation (Δ H  ‡ ) and entropy of activation (Δ S  ‡ ) between enterocytes and branchial cells. Induction of n-3 LCPUFA deficiency dramatically altered membrane lipid composition in enterocytes, being the most dramatic changes the increase in 18:1n-9 (oleic acid) and the reduction of n-3 LCPUFA (mainly DHA, docosahexaenoic acid). Strikingly, branchial cells were much more resistant to diet-induced lipid alterations than enterocytes, indicating the existence of potent lipostatic mechanisms preserving membrane lipid matrix in gill epithelia. Paralleling lipid alterations, values of  Ea  1 , Δ H  ‡  and Δ S  ‡  for the Na + -K + -ATPase were all increased, while  Td  values vanished, in LCPUFA deficient enterocytes. In turn, Differences in thermodynamic parameters were highly correlated with specific changes in fatty acids, but not with individual lipid classes including cholesterol  in vivo . Thus,  Td  was positively related to 18:1n-9 and negatively to DHA.  Td, Ea  1  and Δ H  ‡  were exponentially related to DHA/18:1n-9 ratio. The exponential nature of these relationships highlights the strong impact of subtle changes in the contents of oleic acid and DHA in setting the thermodynamic properties of epithelial Na + -K + -ATPase  in vivo . The effects are consistent with physical effects on the lipid membrane surrounding the enzyme as well as with direct interactions with the Na + -K + -ATPase.

frontiers in physiology

Membrane Lipid Microenvironment Modulates Thermodynamic Properties of the Na+-K+-ATPase in Branchial and Intestinal Epithelia in Euryhaline Fish In vivo