| pubmed-article:7694157 | pubmed:abstractText | The aim of the present study was to search for electrophysiological effects of human lipoproteins on membrane currents in mouse peritoneal macrophages which had been cultured for 5 to 20 days. Whole-cell currents were recorded by using a voltage-clamp technique. Low density lipoprotein (LDL, 100 micrograms/ml) increased a slowly activating nonspecific cation current (iso) in the positive potential range to 244 +/- 23% of the reference (test potential + 55 mV, n = 13, P < 0.005). Augmentation of current resulted out of a negative shift of the activation curve along the voltage axis (-22 mV) and an increase of maximally available current. Furthermore, LDL increased a rapidly activating outward current (ifo) at test potentials positive to the potassium equilibrium potential. At +55 mV ifo-amplitude increased to 165 +/- 14% of reference (n = 16, P < 0.005). LDL-induced effects on ifo-current could be mimicked by application of the calcium ionophore A 23,187 (1 mumol/l) which led to an increase of ifo-current to 161 +/- 25% of the reference (test potential +55 mV, n = 11, P < 0.005). Acetylated-LDL (100 micrograms/ml, 5-15 min) produced no significant effect on the membrane currents under investigation. | lld:pubmed |
