Mononuclear cell membranes: stabilization by reproterol and cromoglycate, destabilization by fenoterol and salbutamol.

Electron paramagnetic resonance (EPR) spectroscopy with spin labels 5- and 16-doxyl-stearic acid (DSA) was used to differentiate between actions of beta-agonists on human mononuclear cell membrane. Reproterol (CAS 13055-82-8), salbutamol (CAS 51022-70-9) and fenoterol (CAS 1944-12-3) compared to cromoglycate (CAS 15826-37-6) were used at concentrations of 10-100 nmol/l per 10(7) cells. With reproterol, order and polarity was not much changed, whereas salbutamol and fenoterol significantly destabilized the membrane to similar extent.

ADP- and oligomycin-sensitive redox behavior of F0 b thiol in ATPsynthase depends on neighbored primary structure: investigations using 14-C-labeled alpha lipoic acid.

Purified ATPsynthase of bovine heart mitochondria has been analyzed for its mobility and reactivity of oligomycin-sensitive sulfhydryl regions in presence of the substrate ADP and oligomycin. Labeling of thiol groups at the hydrophobic F_0 region of the ATPsynthase was increased in the enzyme initially treated with SDS, N-ethylmaleimide and dithiothreitol (modified enzyme). After dialysis or gel permeation the ATPsynthase was treated with [14C] alpha lipoic acid at a molar ratio of 35-85/1 (lipoic acid/ATPsynthase) corresponding to 4-8.

Toxicity of ethanol and acetaldehyde in hepatocytes treated with ursodeoxycholic or tauroursodeoxycholic acid.

In hepatocytes ethanol (EtOH) is metabolized to acetaldehyde and to acetate. Ursodeoxycholic acid (UDCA) and tauroursodeoxycholic acid (TUDCA) are said to protect the liver against alcohol. We investigated the influence of ethanol and acetaldehyde on alcohol dehydrogenase (ADH)-containing human hepatoma cells (SK-Hep-1) and the protective effects of UDCA and TUDCA (0.