BOVINE SERUM-ALBUMIN SELECTIVELY INCREASES THE LOW-VOLTAGE-ACTIVATED CALCIUM CURRENT OF NG108-15 NEUROBLASTOMA X GLIOMA-CELLS

The effect of bovine serum albumin (BSA) on the neuronal Ca2+ current (I-Ca) has been studied in NG108-15 cells. BSA selectively increased t he low-voltage-activated (l-v-a), transient I-Ca but did not affect th e high-voltage-activated (h-v-a) I-CA. The increase of l-v-a I-Ca was partly due to a small shift of its activation curve to more negative v alues of membrane potential and partly to an increase of the maximal a ctivatable current. Fatty-acid-free (FA-free) BSA was about equally ef fective as ordinary BSA; the smallest effective concentration of FA-fr ee BSA was between 0.01 and 0.1 mg/ml.