Study of Changes in Diacylglycerol Content on Nerve Excitation

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V. V. Revin^1*, M. A. Yudanov¹, E. S. Revina¹, G. V. Maksimov², and I. P. Gruniushkin¹

¹Department of Biotechnology, Biological Faculty, Ogarev Mordovian State University, ul. Bolshevistskaya 68, 430000 Saransk, Russia; fax: (8342) 32-4554; E-mail: biotech@moris.ru

²Department of Biophysics, Biological Faculty, Lomonosov Moscow State University, 119992 Moscow, Russia; fax: (495) 939-1115; E-mail: maximov@biophys.msu.ru

^* To whom correspondence should be addressed.

Received November 25, 2005; Revision received April 25, 2006

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Rhythmic excitation of a rabbit myelin nerve increased diacylglycerol (DAG) content from 1.53 to 2.17 µg/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 ⁴⁵Ca 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.

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KEY WORDS: nerve, myelin, rhythmic excitation, phospholipase C, diacylglycerol

DOI: 10.1134/S0006297906100063

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