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

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Interactions of angiotensin II non-peptide AT(1) antagonist losartan with phospholipid membranes studied by combined use of differential scanning calorimetry and electron spin resonance spectroscopy.
    Author: Theodoropoulou E, Marsh D.
    Journal: Biochim Biophys Acta; 1999 Nov 09; 1461(1):135-46. PubMed ID: 10556495.
    Abstract:
    We used differential scanning calorimetry (DSC) and electron spin resonance (ESR) spectroscopy to investigate the interactions of Losartan, a potent, orally active Angiotensin II AT(1) receptor antagonist with phospholipid membranes. DSC results showed that Losartan sensitively affected the chain-melting behavior of dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC) bilayer membranes. ESR spectroscopy showed that phosphatidylcholines spin-labeled at the 5-position of the sn-2 acyl chain (n-PCSL with n=5), incorporated either in DMPC or DPPC bilayers containing Losartan, were restricted in motion both in the gel and in the liquid-crystalline membrane phases, indicating a location of the antagonist close to the interfacial region of the phosphatidylcholine bilayer. At high drug concentrations (mole fraction >/= x=0.60), the decrease in chain mobility registered by 5-PCSL in fluid-phase membranes is smaller than that found at lower concentrations, whereas that registered by 14-PCSL is further increased. This indicates a different mode of interaction with Losartan at high concentrations, possibly arising from a location deeper within the bilayer. Additionally, Losartan reduced the spin-spin broadening of 12-PCSL spin labels in the gel-phase of DMPC and DPPC bilayers. As a conclusion, our study has shown that Losartan interacts with phospholipid membranes by affecting both their thermotropic behavior and molecular mobility.
    [Abstract] [Full Text] [Related] [New Search]