Reference

Current fluctuation analysis of alamethicin pores in black lipid membranes

Current fluctuation analysis of alamethicin pores in black lipid membranes. Effect of lanthanum ions. Gogelein, H.; De Smedt, H.; Van Driessche, W.; Borghgraef, R. (Lab. Fysiol., Katholieke Univ. Leuven, Louvain, Belg.). Arch. Int. Physiol. Biochim., 85(3), 628-30 (English) 1977. CODEN: AIPBAY. DOCUMENT TYPE: Journal CA Section: 3 (Biochemical Interactions) The formation of alamethicin [27061-78-5] pores in black lipid membranes (made from a 1:1 mixt. of dioleoyllecithin with cholesterol in decane) was measured from current fluctuations at const. voltage following addn. of alamethacin to solns. bathing both sides of the membrane. The fluctuations appeared at a higher voltage in the presence of La3+ than in its absence. The no. of pores depended on both the alamethicin concn. and the applied voltage.

Desensitized beta-adrenoceptors of C6-glioma cells have distinct binding properties

Desensitized beta-adrenoceptors of C6-glioma cells have distinct binding properties. Hertel, C.; Affolter, H.; Portenier, M.; Staehelin, M. (Friedrich Miescher-Inst., Basel CH-4002, Switz.). Naunyn-Schmiedeberg's Arch. Pharmacol., 328(1), 51-5 (English) 1984. CODEN: NSAPCC. ISSN: 0028-1298. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 2, 4 When C6-rat glioma cells were incubated for 20 min with b-adrenoceptor agonists, a part of the b-adrenoceptors was localized in light d. vesicles. These receptors have the same affinity for dihydroalprenolol [60106-89-0] as plasma membrane receptors but have a lowered affinity for agonists as well as for the hydrophilic b-adrenoceptor antagonist CGP-12177 [81047-99-6]. The affinity of these vesicular receptors for a variety of hydrophobic b-blockers as well as for the hydrophilic b-blocker (-)-timolol maleate [26921-17-5] compared with that of plasma membrane receptors. None of the ligands investigated showed any difference in affinity but CGP-12177. Both, introducing a lipophilic side chain into CGP-12177 or altering the benzimidazol-2-one ring system of CGP-12177 led to an increase in the affinity of the vesicular receptors. Since in the presence of the pore-forming agent alamethicin [27061-78-5] the same affinity was detd. for vesicular receptors as for those located on the plasma membrane, it is concluded that the apparent low affinity of the vesicular receptors in the absence of alamethicin is caused by a membrane barrier. The lower affinity of the vesicular receptors for agonists was only slightly increased by alamethicin.