Biomaterial Database

Effect of essential fatty acid deficiency on forskolin binding sites, adenylate cyclase and cyclic AMP-dependent protein kinase activity, the levels of G proteins and ventricular function in rat heart. 1995

S Q Alam, and S J Mannino, and B S Alam, and K McDonough

Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, New Orleans 70119, USA.

Three groups of rats were fed semi-purified diets. Diet I was deficient in essential fatty acids (EFAD), diet II was marginally deficient in essential fatty acids (MEFAD), and diet III contained adequate levels of essential fatty acids (control). After 9 weeks, some rats within each group were killed and cardiac membranes were prepared. Adenylate cyclase activity, [3H]forskolin binding sites, the levels of G proteins (Gi and Gs) and fatty acid composition of the membrane phospholipids were measured. Typical changes of EFA deficiency were observed in fatty acid composition of the membrane phospholipids. Adenylate cyclase activity was significantly lower in membranes of EFA-deficient rats than those of the controls. The MEFAD group gave intermediate values. Similar results were obtained with forskolin-stimulated activity with different concentrations of forskolin. Concentrations of the forskolin binding sites were also lower in the EFAD, but not in the MEFAD rats compared with the controls. There was no significant difference in forskolin binding affinities among the three groups. The decrease in adenylate cyclase activity in EFA-deficient rat heart was partially restored by feeding the control diet for 5 weeks to the EFAD or the MEFAD rats. The levels of Gi alpha and Gs alpha were not significantly different in cardiac membranes of rats fed the EFAD or the MEFAD diets from those of the control group. Lower adenylate cyclase activity in hearts of EFAD rats was also reflected in correspondingly lower activity of cAMP-dependent protein kinase. The results suggest an impairment of the cellular signalling pathway for the production of cAMP in rat heart during EFA deficiency. The beta-adrenergic response of isolated heart preparations obtained from rats fed the three diets was, however, not significantly altered.

UI	MeSH Term	Description	Entries
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D008297	Male		Males
D008563	Membrane Lipids	Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.	Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
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
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D005228	Fatty Acids, Essential	Long chain organic acid molecules that must be obtained from the diet. Examples are LINOLEIC ACIDS and LINOLENIC ACIDS.	Acids, Essential Fatty,Essential Fatty Acids