Study of changes in diacylglycerol content on nerve excitation.
Rhythmic excitation of a rabbit myelin nerve increased diacylglycerol (DAG) content from 1.53 to 2.17 microg/mg lipids. Inhibition of phosphoinositide-specific phospholipase C decreased DAG content. This suggests involvement of this enzyme in processes accompanying rhythmic excitation. The increase in membrane potential of the nerve fiber (K+-depolarization) was accompanied by increase in DAG and phosphatidylinositol monophosphate and decrease in phosphatidylinositol triphosphate and phosphatidylinositol diphosphate content. Treatment of the nerve with DAG or a protein kinase C activator increased (45)Ca influx by 40%, whereas treatment with an inhibitor of this enzyme, polymyxin, inhibited this parameter by 34%. The role of phosphoinositides and protein kinase C in the regulation of Ca2+ transport during rhythmic excitation of the myelin nerve is discussed.
Revin
V V
VV
Department of Biotechnology, Biological Faculty, Ogarev Mordovian State University, Saransk, 430000, Russia. biotech@moris.ru
Yudanov
M A
MA
Revina
E S
ES
Maksimov
G V
GV
Gruniushkin
I P
IP
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011817:Rabbits; D012584:Sciatic Nerve / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology
C011439:1,2-diacylglycerol; D004075:Diglycerides; D004791:Enzyme Inhibitors; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; C060974:phosphatidylinositol 3,4,5-triphosphate; D010664:Phenylmethylsulfonyl Fluoride; D011493:Protein Kinase C; D002118:Calcium