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Title: Effect of. cap alpha. /sub 1/-adrenergic stimulation on phosphoinositide metabolism and protein kinase C (PK-C) in rat cardiomyocytes

Alpha/sub 1/-adrenergic stimulation is known to enhance membrane phospholipid metabolism resulting in increases in inositol phosphates (IP's) and diacylglycerol (DAG). Cardiomyocytes prelabeled with /sup 3/H-myo-inositol were treated with norepinephrine (NE) for 1-15 min, acid extracted, and IP's separated by ion exchange chromatography. Addition of NE (10/sup -5/M) in the presence of propranolol (10/sup -5/ M) and LiCl (9 mM) enhanced the accumulation of IP's, linearly with time up to 15 min, and reached 7.3, and 1.5-fold at 15 min for IP/sub 1/, IP/sub 2/, and IP/sub 3/, respectively. KCl at 30 mM had no effect on accumulation of IP's, but augmented the effect of NE. PK-C activity was measured in both cytosol (S) and particulate (P) fractions of treated cells. NE alone had a negligible effect on membrane PK-C, while 30 mM KCl caused a small increase. However, pretreatment with KCl followed by NE produced a significant increase above that seen with KCl alone. Dioctanoylglycerol also stimulated membrane association of PK-C in these cells. These data suggest that ..cap alpha../sub 1/-adrenergic stimulation of membrane association of myocardial PK-C is mediated by DAG but may be dependent on membrane potential and/or the extent of Ca/sup 2 +/ loading.
Authors:
; ;
Publication Date:
OSTI Identifier:
5435771
Report Number(s):
CONF-8604222-
Journal ID: CODEN: FEPRA; TRN: 86-026655
Resource Type:
Conference
Resource Relation:
Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States); Journal Volume: 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; INOSITOL; METABOLISM; PHOSPHOTRANSFERASES; ENZYME ACTIVITY; SYMPATHOMIMETICS; BIOLOGICAL EFFECTS; ANIMAL CELLS; CALCIUM; CELL MEMBRANES; GLYCEROL; HEART; ION EXCHANGE CHROMATOGRAPHY; NORADRENALINE; POTASSIUM CHLORIDES; TRACER TECHNIQUES; TRITIUM COMPOUNDS; ADRENAL HORMONES; ALCOHOLS; ALKALI METAL COMPOUNDS; ALKALINE EARTH METALS; AUTONOMIC NERVOUS SYSTEM AGENTS; BODY; CARBOHYDRATES; CARDIOTONICS; CARDIOVASCULAR AGENTS; CARDIOVASCULAR SYSTEM; CELL CONSTITUENTS; CHLORIDES; CHLORINE COMPOUNDS; CHROMATOGRAPHY; DRUGS; ELEMENTS; ENZYMES; HALIDES; HALOGEN COMPOUNDS; HORMONES; HYDROXY COMPOUNDS; INOSITOLS; ISOTOPE APPLICATIONS; LABELLED COMPOUNDS; MEMBRANES; METALS; MONOSACCHARIDES; NEUROREGULATORS; ORGANIC COMPOUNDS; ORGANS; PHOSPHORUS-GROUP TRANSFERASES; POTASSIUM COMPOUNDS; SACCHARIDES; SEPARATION PROCESSES; STEROID HORMONES; TRANSFERASES 550501* -- Metabolism-- Tracer Techniques