Glombitza, Stefan and Dragon, Stefanie and Berghammer, Margit and Pannermayr, Markus and Baumann, Rosemarie (1996) Adenosine causes cAMP-dependent activation of chick embryo red cell carbonic anhydrase and 2,3-DPG synthesis. AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, 271 (4). R973-R981. ISSN 0363-6119, 1522-1490
Full text not available from this repository.Abstract
In late chick embryos, coordinate activation of red cell carbonic anhydrase II (CAII) and 2,3-diphosphoglycerate (2,3-DPG) synthesis is initiated by hypoxia. The effects are mediated by unidentified hormonal effecters resident in chick plasma. In the present investigation, we have analyzed the effect of adenosine receptor stimulation on embryonic red cell CAII and 2,3-DPG synthesis. We find that primitive and definitive embryonic red blood cells from chick have an Az, adenosine receptor. Stimulation of the receptor with metabolically stable adenosine analogues causes a large increase of red cell adenosine 3',5'-cyclic monophosphate (cAMP) and subsequent activation of red cell CAII and 2,3-DPG production in definitive red blood cells and of CAII synthesis in primitive red blood cells. Direct stimulation of adenylyl cyclase with forskolin has the same effect. Analysis of red cell protein pattern after labeling with [S-35] methionine shows that stimulation of red cell cAMP levels activates synthesis of several other proteins aside from CAII. Presence of actinomycin D inhibits cAMP-dependent changes of protein synthesis, indicating that cAMP-dependent transcriptional activation is required. In contrast to the stable adenosine receptor analogues, adenosine itself was a very weak agonist, unless its metabolism was significantly inhibited. Thus, besides adenosine, other effecters of the adenylyl cyclase system are likely to be involved in the O-2 pressure-dependent regulation of red cell metabolism in late development of avian embryos.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | KINASE INHIBITOR; OXYGEN-AFFINITY; 5-IODOTUBERCIDIN; ERYTHROCYTES; RECEPTORS; HYPOXIA; AGONIST; actinomycin D; protein synthesis; iodotubercidin; forskolin; adenylyl cyclase |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Physiologie > Alumni or Retired > Prof. Dr. Rosemarie Baumann |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 22 Jun 2023 09:06 |
| Last Modified: | 22 Jun 2023 09:06 |
| URI: | https://pred.uni-regensburg.de/id/eprint/51426 |
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