Effect of Imidazole and its Derivatives on Norepinephrine-, ACTH-, Theophylline- and Dibutyryl Cyclic AMP-Induced Lipolysis in Isolated Rat Fat Cells

Pharmacology ◽  
1970 ◽  
Vol 3 (5) ◽  
pp. 273-281 ◽  
Author(s):  
J. Nakano ◽  
R. Oliver ◽  
T. Ishii
Keyword(s):  
Cyclic Amp ◽  
Fat Cells ◽  
Dibutyryl Cyclic Amp ◽  
Rat Fat Cells ◽  
Isolated Rat

scholarly journals The action of local anaesthetics on lipolysis and on adenosine 3′:5′-cyclic monophosphate content in isolated rat fat-cells

1974 ◽  
Vol 142 (2) ◽  
pp. 345-351 ◽  
Author(s):  
Kenneth Siddle ◽  
C. Nicholas Hales
Keyword(s):  
Cyclic Amp ◽  
Glucose Uptake ◽  
Local Anaesthetics ◽  
Inhibitory Effect ◽  
Fat Cells ◽  
Atp Content ◽  
Dibutyryl Cyclic Amp ◽  
Ion Movements ◽  
Rat Fat Cells ◽  
Isolated Rat

1. Local anaesthetics inhibited hormone-stimulated lipolysis in isolated rat fat-cells. The most potent anaesthetic was dibucaine, which inhibited adrenaline-stimulated lipolysis by 50% at a concentration of 0.16mm. 2. The amount of inhibition produced by a given concentration of anaesthetic was very similar with adrenaline, theophylline and dibutyryl cyclic AMP, at submaximal and maximal concentrations. 3. The inhibitory effect of dibucaine on lipolysis was apparent within 5 min and was constant over 1h. 4. Dibucaine inhibited basal, adrenaline-stimulated and insulin-stimulated glucose uptake at concentrations 6–10-fold higher than those inhibiting lipolysis. 5. The effects of dibucaine on lipolysis and glucose uptake were reversed after removal of anaesthetic and washing of cells. 6. Dibucaine further elevated the concentration of cyclic AMP in the presence of adrenaline or adrenaline plus theophylline. 7. Dibucaine had no effect on ATP content at concentrations causing 80% inhibition of lipolysis, but lowered ATP content at higher concentrations. 8. The relative potency of different local anaesthetics as inhibitors of hormone-stimulated lipolysis paralleled their potency as inhibitors of ion movements in other systems. 9. The possibility is discussed that Ca2+ions are involved in the regulation of lipolysis, and that local anaesthetics inhibit lipolysis by interfering with Ca2+translocation.

scholarly journals The relationship between the concentration of adenosine 3′:5′-cyclic monophosphate and the anti-lipolytic action of insulin in isolated rat fat-cells

1974 ◽  
Vol 142 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Kenneth Siddle ◽  
C. Nicholas Hales
Keyword(s):  
Cyclic Amp ◽  
Time Course ◽  
Immunoreactive Insulin ◽  
Fat Cells ◽  
Lipolytic Action ◽  
Wide Range ◽  
Early Peak ◽  
The Relationship ◽  
Rat Fat Cells ◽  
Isolated Rat

The relationship between cyclic AMP content and lipolysis, as measured by glycerol formation, was studied in isolated rat fat-cells. Inhibition of lipolysis by insulin in the presence of a low concentration of adrenaline was accompanied by little or no lowering of cyclic AMP content, measured after 15min incubation. The time-course of cyclic AMP content after addition of adrenaline showed that the effect of insulin in lowering cyclic AMP content measured after 2–5min was gradually lost over the next hour, mainly because of the fall in cyclic AMP content after an early peak in the presence of adrenaline alone. There was a 44% loss of immunoreactive insulin, from an initial concentration of 0.3nm, during a 1h incubation with fat-cells. Insulin did not affect partitioning of cyclic AMP between cells and incubation medium. When the correlation between cyclic AMP content and rate of lipolysis was investigated for a wide range of adrenaline concentrations, it was found that the lowering of cyclic AMP content by insulin was much less than that required to account for the amount of inhibition of lipolysis. It is concluded that inhibition of adrenaline-stimulated lipolysis by insulin involves factors in addition to a decrease in intracellular cyclic AMP concentration.

Lipoprotein lipase secretion from isolated rat fat cells of different size

Life Sciences ◽  
1986 ◽  
Vol 39 (22) ◽  
pp. 2111-2119 ◽  
Author(s):  
Susan K. Fried ◽  
Mario DiGirolamo
Keyword(s):  
Lipoprotein Lipase ◽  
Fat Cells ◽  
Rat Fat Cells ◽  
Isolated Rat

scholarly journals A rapid immunological procedure for the isolation of hormonally sensitive rat fat-cell plasma membrane

1976 ◽  
Vol 154 (1) ◽  
pp. 11-21 ◽  
Author(s):  
J P Luzio ◽  
A C Newby ◽  
C N Hales
Keyword(s):  
Plasma Membrane ◽  
Adenylate Cyclase ◽  
Plasma Membranes ◽  
Membrane Preparation ◽  
Fat Cells ◽  
Fat Cell ◽  
Cell Plasma ◽  
Rat Fat Cells ◽  
Plasma Membrane Preparation ◽  
Isolated Rat

1. A rapid method for the isolation of hormonally sensitive rat fat-cell plasma membranes was developed by using immunological techniques. 2. Rabbit anti-(rat erythrocyte) sera were raised and shown to cross-react with isolated rat fat-cells. 3. Isolated rat fat-cells were coated with rabbit anti-(rat erythrocyte) antibodies, homogenized and the homogenate made to react with an immunoadsorbent prepared by covalently coupling donkey anti-(rabbit globulin) antibodies to aminocellulose. Uptake of plasma membrane on to the immunoadsorbent was monitored by assaying the enzymes adenylate cyclase and 5′-nucleotidase and an immunological marker consisting of a 125I-labelled anti-(immunoglobulin G)-anti-cell antibody complex bound to the cells before fractionation. Contamination of the plasma-membrane preparation by other subcellular fractions was also investigated. 4. By using this technique, a method was developed allowing 25-40% recovery of plasma membrane from fat-cell homogenates within 30 min of homogenization. 5. Adenylate cyclase in the isolated plasma-membrane preparation was stimulated by 5 μm-adrenaline.

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