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

Phospholipid methylation of canine cardiac membranes was studied in vitro to determine its relationship to the regulation and function of beta-adrenergic and digitalis receptors. Cardiac membranes were prepared from the left ventricle of mongrel dogs. Phospholipid methylation was assayed by measuring [3H] methyl incorporation after incubation with methyl donor S-adenosyl-L-[methyl-3H] methione at 37 degrees C. The reaction of phospholipid methylation had an optimum pH around 9 and a linear time course of up to 60 min. The reaction was inhibited by the addition of S-adenosyl-L-homocysteine, a known antagonist of biological transmethylation. L-isoproterenol enhanced phospholipid methylation markedly, but ouabain had no effect. On the other hand, after phospholipid methylation in cardiac membranes was stimulated by pre-incubation with S-adenosyl-L-methionine for 60 min at 37 degrees C, [125I] iodohydroxybenzylpindolol binding to the membranes was increased. The number of the beta-adrenergic receptor binding sites (Bmax), calculated from Scatchard analysis in cardiac membranes of 3 dogs significantly increased. On the other hand, [3H] ouabain binding and Na+, K+, Mg2+-ATPase activity were not increased. The increase in [125I] iodohydroxybenzylpindolol binding was inhibited by the addition of S-adenosyl-L-homocysteine. These binding suggest that phospholipid methylation is closely related to beta-adrenergic receptors, but not digitalis receptors in cardiac membranes.

Phospholipid methylation in canine cardiac membranes. Relations to .BETA.-adrenergic receptors and digitalis receptors.