These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Structure activity relationship of cholesterol and steroid hormones with respect to their effects on the Ca2+-stimulated ATPase and lipid fluidity of synaptosomal plasma membranes from dog and rabbit brain.
    Author: Deliconstantinos G.
    Journal: Comp Biochem Physiol B; 1988; 89(3):585-94. PubMed ID: 2966032.
    Abstract:
    1. Binding of liposomal-[14C]-cholesterol into dog brain synaptosomal plasma membranes (SPM) follows a sigmoid path (Hill coefficient h = 1.96 +/- 0.12). 2. Ca2+-stimulated ATPase activity increased (approx. 95%) at a concentration range (0.1-0.4 mM) of liposomal cholesterol and testosterone (up to 10 microM). While progesterone up to 10 microM decreased the enzyme activity (approx. 70%) in dog and rabbit brain SPM. 3. Fluorescence anisotropy, [(r0/r)-1]-1, of 1,6-diphenyl-1,3,5-hexatriene (DPH) was 1.04 +/- 0.04 in rabbit brain SPM and 1.72 +/- 0.09 in dog brain SPM. 4. Lipid phase separations at 23.5 +/- 1.2 degrees C in dog brain SPM and at 17.2 +/- 0.9 degrees C in rabbit brain SPM were observed. In dog brain SPM it increased to 33.4 +/- 1.8 degrees C, while in rabbit brain SPM was abolished after treatment with liposomal cholesterol. 5. The allosteric inhibition of Ca2+-stimulated ATPase by Na+ ions showed a Hill coefficient h = 1.72 +/- 0.15 and h = 1.48 +/- 0.08 for dog and rabbit brain SPM respectively, which increased to h = 2.83 +/- 0.55 and h = 2.34 +/- 0.35 after treatment with liposomal cholesterol.
    [Abstract] [Full Text] [Related] [New Search]