Effect of modulators of protein kinase C activity on Ca2+ transport in retinal rod microsomes.
The effect of modulators of protein kinase C (PKC) activity on Ca2+ translocation in retinal rod microsomes was studied. It is shown that PKC activators (phorbol 12-myristate-13-acetate (PMA) and diacylglycerol (DAG)) and inhibitors (chelerythrine chloride, polymyxin B, and phloretin) stimulate and inhibit ATP-dependent Ca2+ uptake in retinal rod microsomes, respectively. This effect is apparently due to an influence of PKC on Ca-ATPase contained in these vesicular structures. It was found that PKC inhibitors (chelerythrine chloride, polymyxin B, and phloretin) and activators (PMA and DAG) potentiate Ca2+ release from Ca2+-loaded retinal rod microsomes. Specific and nonspecific mechanisms of Ca-release stimulation by the modulators of PKC activity are discussed.
Emeljanova
V P
VP
Institute of Photobiology, National Academy of Sciences of Belarus, Minsk, 220072, Belarus. kabash@biobel.bas.net.by
Baranova
L A
LA
Volotovski
I D
ID
D000470:Alkaloids; D000818:Animals; D053119:Benzophenanthridines; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D004075:Diglycerides / Q000494:pharmacology; D020536:Enzyme Activators / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D066298:In Vitro Techniques; D008861:Microsomes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010617:Phenanthridines / Q000494:pharmacology; D010693:Phloretin / Q000494:pharmacology; D011112:Polymyxin B / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D017948:Retinal Rod Photoreceptor Cells / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000470:Alkaloids; D053119:Benzophenanthridines; D004075:Diglycerides; D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D010617:Phenanthridines; C016299:chelerythrine; D011493:Protein Kinase C; D011112:Polymyxin B; D013755:Tetradecanoylphorbol Acetate; D010693:Phloretin; D002118:Calcium