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Activation and desensitization of glycolysis by stimulation of adenylate cyclase in rat reticulocytes
Author(s) -
Kostić M.M.,
Maretzki D.,
Źivković R.,
Krause E.G.,
Rapoport S.M.
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)80656-7
Subject(s) - adenylate kinase , cyclase , desensitization (medicine) , stimulation , glycolysis , chemistry , endocrinology , medicine , biochemistry , biology , metabolism , enzyme , receptor
Isoproterenol or forskolin induce a 10–15‐fold increase in concentration of cyclic AMP in rat reticulocytes as compared with the basal level of 2.3 ± 0.3 μM. Glycolysis is stimulated by both compounds transiently more than 2‐fold with a peak after 7.5 min followed by an exponential decline. The glycolytic rate in the presence of 1O μM isoproterenol or 10 μM forskolin did not return to basal levels within 60 min of incubation, but was depressed by as much as 50% under the influence of 100 μM forskolin. This phenomenon is designated as metabolic desensitization. The stimulation of glycolysis is probably due to activation of phosphofructokinase as well as to stimulation of Na + ,K + ‐ATPase. The diminished glycolytic flux during the period of metabolic desensitization is accompanied by a decline of glucose 6‐phosphate and in the presence of high concentrations of forskolin also by a decrease in glucose 1,6‐bisphosphate. A lower rate of influx of glucose is postulated.