Effects of cytochalasin B, colchicine and vincristine on the metabolism of isolated fat-cells.
1. Colchicine and vincristine only slightly inhibit the metabolism of glucose to CO(2) and lipids by isolated fat-cells. 2. Prolonged incubation with these agents causes no further inhibition. 3. Cytochalasin B, however, inhibits glucose metabolism to both CO(2) and lipids in fat-cells. 4. However, at a concentration that causes a strong inhibition of glucose metabolism cytochalasin B is without effect on the metabolism of pyruvate, lactate or arginine to these end products. The uptake of labelled alpha-aminoisobutyrate is likewise not modified. Similarly it does not affect release of glycerol or free fatty acid, or the actions of adrenaline, insulin or caffeine on these parameters. At 10mug/ml it slightly lowers ATP concentrations, an effect that does not occur at 2mug/ml. 5. The transport of fructose into adipocytes by a specific fructose-transport system is also not affected by the agent, but the uptake of 2-deoxyglucose is strongly inhibited. It is concluded that cytochalasin B may specifically inhibit the glucose-transport system of isolated fat-cells. 6. Cytochalasin A has a much weaker action than cytochalasin B on glucose metabolism.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects*; D000621:Aminoisobutyric Acids / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000378:metabolism; D002110:Caffeine / Q000494:pharmacology; D002245:Carbon Dioxide / Q000378:metabolism; D002250:Carbon Radioisotopes; D002498:Centrifugation; D003078:Colchicine / Q000494:pharmacology*; D003571:Cytochalasin B / Q000494:pharmacology*; D004837:Epinephrine / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D007773:Lactates / Q000378:metabolism; D008297:Male; D011773:Pyruvates / Q000378:metabolism; D051381:Rats; D014750:Vincristine / Q000494:pharmacology*
D000621:Aminoisobutyric Acids; D002250:Carbon Radioisotopes; D007328:Insulin; D007773:Lactates; D011773:Pyruvates; D002245:Carbon Dioxide; D003571:Cytochalasin B; D002110:Caffeine; D014750:Vincristine; D000255:Adenosine Triphosphate; D001120:Arginine; D005947:Glucose; D005990:Glycerol; D003078:Colchicine; D004837:Epinephrine