Referenced in: none

Automatically associated channels: Slo1

Title: The inhibitory effect of BIM (I) on L-type Ca(2+) channels in rat ventricular cells.

Authors: Youn Kyoung Son, Da Hye Hong, Tae-Hoon Choi, Seong Woo Choi, Dong Hoon Shin, Sung Joon Kim, In Duk Jung, Yeong-Min Park, Won-Kyo Jung, Dae-Joong Kim, Il-Whan Choi, Won Sun Park

Journal, date & volume: , 2012 May 22 , ,

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22634012

Abstract
We investigated the effect of a specific protein kinase C (PKC) inhibitor, bisindolylmaleimide I [BIM (I)], on L-type Ca(2+) channels in rat ventricular myocytes. BIM (I) alone inhibited the L-type Ca(2+) current in a concentration-dependent manner, with a K(d) value of 3.31 ± 0.25 μM, and a Hill coefficient of 2.34 ± 0.23. Inhibition was immediate after applying BIM (I) in the bath solution and then it partially washed out. The steady-state activation curve was not altered by applying 3μ M BIM (I), but the steady-state inactivation curve shifted to a more negative potential with a change in the slope factor. Other PKC inhibitors, PKC-IP and chelerythrine, showed no significant effects either on the L-type Ca(2+) current or on the inhibitory effect of BIM (I) on the L-type Ca(2+) current. The results suggest that the inhibitory effect of BIM (I) on the L-type Ca(2+) current is independent of the PKC pathway. Thus, our results should be considered in studies using BIM (I) to inhibit PKC activity and ion channel modulation.