BIOMAT Database Logo BIOMAT Database Logo

1,2-Dioctanoyl-sn-glycerol depresses cardiac L-type Ca2+ current: independent of protein kinase C activation. 1996

K D Schreur, and S Liu
Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock 72205, USA.

The present study examines the effect of 1,2-dioctanoyl-sn-glycerol (DiC8), a diacylglycerol analogue, on L-type Ca2+ current (ICa,L) in adult rat ventricular myocytes using whole cell patch-clamp techniques. Extracellular application of DiC8 (1-10 microM) resulted in a concentration-dependent inhibition of peak ICa,L (half-maximum inhibitory concentration = 2.2 microM). Results obtained from the current-voltage relationship showed that DiC8 decreased the slope conductance. In addition, DiC8 increased the rate of Ba2+ current inactivation and caused a hyperpolarizing shift in the steady-state inactivation by 6 mV and a decrease in the slope factor. The DiC8-induced inhibition of ICa,L was neither mimicked by activation of protein kinase C (PKC) with 100 nM phorbol 12-myristate 13-acetate (PMA) no prevented by inhibition of PKC with 30 microM H-7, 100 nM staurosporine, or 24-h pretreatment with PMA. These results suggest that in rat ventricular myocytes 1) 1,2-sn-diacylglycerol (DAG) inhibits ICa,L, possibly by facilitating channel inactivation and decreasing channel availability and 2) this inhibitory effect of DAG is independent of PKC activation.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D008297 Male Males
D009206 Myocardium The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow. Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D011493 Protein Kinase C An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters. Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002478 Cells, Cultured Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others. Cultured Cells,Cell, Cultured,Cultured Cell
D004075 Diglycerides Glycerides composed of two fatty acids esterified to the trihydric alcohol GLYCEROL. There are two possible forms that exist: 1,2-diacylglycerols and 1,3-diacylglycerols. Diacylglycerol,Diacylglycerols
D004553 Electric Conductivity The ability of a substrate to allow the passage of ELECTRONS. Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D004789 Enzyme Activation Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme. Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006706 Homeostasis The processes whereby the internal environment of an organism tends to remain balanced and stable. Autoregulation

Related Publications

K D Schreur, and S Liu
Dioctanoyl-glycerol inhibits L-type calcium current in embryonic chick cardiomyocytes independent of protein kinase C activation.
May 1995, Journal of molecular and cellular cardiology,
K D Schreur, and S Liu
Contrasting effects of sn-1,2-dioctanoyl glycerol as compared to other protein kinase C activators in adrenal glomerulosa cells.
September 1991, The Journal of steroid biochemistry and molecular biology,
K D Schreur, and S Liu
Calcium influx through 'L'-type channels into rat anterior pituitary cells can be modulated in two ways by protein kinase C (PKC-isoform selectivity of 1,2-dioctanoyl sn-glycerol?).
October 1991, FEBS letters,
K D Schreur, and S Liu
Evidence that protein kinase C alpha has reduced affinity towards 1,2-dioctanoyl-sn-glycerol: the effects of lipid activators on phorbol ester binding and kinase activity.
June 1993, European journal of pharmacology,
K D Schreur, and S Liu
Inhibition of MCF-7 cell growth by 12-O-tetradecanoylphorbol-13-acetate and 1,2-dioctanoyl-sn-glycerol: distinct effects on protein kinase C activity.
December 1988, Cancer research,
K D Schreur, and S Liu
Activation of human neutrophil protein kinase C in vitro by 1,2-isopropylidene-3-decanoyl-sn-glycerol (IpOCOC9).
January 1989, Cellular signalling,
K D Schreur, and S Liu
Specificity and mechanism of protein kinase C activation by sn-1,2-diacylglycerols.
March 1986, Proceedings of the National Academy of Sciences of the United States of America,
K D Schreur, and S Liu
Cyclic GMP depresses hippocampal Ca2+ current through a mechanism independent of cGMP-dependent protein kinase.
October 1988, Neuron,
K D Schreur, and S Liu
Protein kinase C activation during Ca2+-independent vascular smooth muscle contraction.
July 1998, The Journal of surgical research,
K D Schreur, and S Liu
1,2-Dioctanoyl-glycerol induces a discrete but transient translocation of protein kinase C as well as the inhibition of MCF-7 cell proliferation.
February 1988, Biochemical and biophysical research communications,
Copied contents to your clipboard!