TY - JOUR
T1 - Effects of protein kinase C activation on sodium, potassium, chloride, and total CO2 transport in the rabbit cortical collecting tubule
AU - Hays, S. R.
AU - Baum, M.
AU - Kokko, J. P.
PY - 1987
Y1 - 1987
N2 - Several hormones induce phosphatidylinositol turnover in cell membranes and thus activate protein kinase C. Activation of protein kinase C can, in turn, have effects on epithelial transport. These experiments were designed to investigate the effects of two activators of protein kinase C, phorbol 12-myristate, 13-acetate (PMA) and L-α-1,2-dioctanoylglycerol (L-α-1,2-DOG), and two inactive analogues, 4α-phorbol and 4-O-methyl phorbol 12-myristate,13-acetate, on sodium, potassium, chloride, and total CO2 transport in the rabbit cortical collecting tubule. Utilizing in vitro microperfusion techniques, we found that activation of protein kinase C with either PMA or L-α-1,2-DOG significantly inhibited net sodium absorption, net potassium secretion and transepithelial voltage in a dose-dependent manner. There was no effect on net chloride or total CO2 transport. In contrast, the inactive phorbol analogues did not alter either sodium or potassium transport. These studies demonstrate that in the rabbit cortical collecting tubule sodium and potassium transport can be inhibited by compounds known to activate protein kinase C. Thus, hormones that induce phosphatidylinositol turnover in the rabbit cortical collecting tubule may lead to inhibition of sodium transport by activation of protein kinase C.
AB - Several hormones induce phosphatidylinositol turnover in cell membranes and thus activate protein kinase C. Activation of protein kinase C can, in turn, have effects on epithelial transport. These experiments were designed to investigate the effects of two activators of protein kinase C, phorbol 12-myristate, 13-acetate (PMA) and L-α-1,2-dioctanoylglycerol (L-α-1,2-DOG), and two inactive analogues, 4α-phorbol and 4-O-methyl phorbol 12-myristate,13-acetate, on sodium, potassium, chloride, and total CO2 transport in the rabbit cortical collecting tubule. Utilizing in vitro microperfusion techniques, we found that activation of protein kinase C with either PMA or L-α-1,2-DOG significantly inhibited net sodium absorption, net potassium secretion and transepithelial voltage in a dose-dependent manner. There was no effect on net chloride or total CO2 transport. In contrast, the inactive phorbol analogues did not alter either sodium or potassium transport. These studies demonstrate that in the rabbit cortical collecting tubule sodium and potassium transport can be inhibited by compounds known to activate protein kinase C. Thus, hormones that induce phosphatidylinositol turnover in the rabbit cortical collecting tubule may lead to inhibition of sodium transport by activation of protein kinase C.
UR - http://www.scopus.com/inward/record.url?scp=0023490561&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023490561&partnerID=8YFLogxK
U2 - 10.1172/JCI113242
DO - 10.1172/JCI113242
M3 - Article
C2 - 3680514
AN - SCOPUS:0023490561
SN - 0021-9738
VL - 80
SP - 1561
EP - 1570
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 6
ER -