Effects of choleragen on hormonal responsiveness of adenylate cyclase in human fibroblasts and rat fat cells
| Autor: | Martha Vaughan, Vincent C. Manganiello, Christopher J. Lovell-Smith |
|---|---|
| Rok vydání: | 1976 |
| Předmět: |
Male
medicine.medical_specialty Bacterial Toxins Biophysics Adenylate kinase Adipose tissue Biology Biochemistry Cyclase chemistry.chemical_compound Fluorides Theophylline Internal medicine medicine Cyclic AMP Animals Humans Prostaglandin E1 Molecular Biology Incubation Vibrio cholerae Cells Cultured Skin Prostaglandins E Isoproterenol Fibroblasts Rats Kinetics Endocrinology chemistry Adipose Tissue Hormone Adenylyl Cyclases |
| Zdroj: | Biochimica et biophysica acta. 451(1) |
| ISSN: | 0006-3002 |
| Popis: | Choleragen increases cyclic AMP content of confluent human fibroblasts. Maximally effective concentrations of isoproterenol and prostaglandin E1 also induce large increases in cyclic AMP content of human fibroblasts and in confluent cultures the effect of prostaglandin E1 is much greater than that of isoproterenol. After incubation with choleragen, the increment in cyclic AMP produced by 2 μM isoproterenol is increased and approaches that produced by 5.6 μM prostaglandin E1. Although the concentration of isoproterenol which produces a maximal increase in cyclic AMP is similar in both control and choleragen-treated cells, lower concentrations of isoproterenol are more effective in the choleragen-treated cells. In choleragen-treated cells, although the response to 5.6 μM prostaglandin E1 is reduced by as much as 50%, the concentration of prostaglandin E1 required to induce a maximal increase in cyclic AMP is 1 10 that required in control cells. Thus the capacities of intact human fibroblasts to respond to isoproterenol and prostaglandin E1 can be altered independently during incubation of intact cells with choleragen. Differences in responsiveness to the two agonists were not demonstrable in adenylate cyclase preparations from control or choleragen-treated cells. In rat fat cells, the effects of choleragen on cyclic AMP content were much smaller than those in fibroblasts. In contrast to its effect on intact fibroblasts, choleragen treatment of rat fat cells did not alter the accumulation of cyclic AMP in response to a maximally effective concentration of isoproterenol. The responsiveness of adenylate cyclase preparations to isoproterenol was also not altered by exposure of fat cells to choleragen. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|