Maturation-dependent changes of the rat reticulocyte energy metabolism and hormonal responsiveness
Kostić, M.M.; Zivković, R.V.; Rapoport, S.M.
Biomedica Biochimica Acta 49(2-3): S178-S182
1990
ISSN/ISBN: 0232-766X PMID: 2167079 Document Number: 356273
Significant reduction of total and coupled respiration as well as an increase of uncoupled respiration characterize the maturation of rat reticulocytes. ATP declines by 45%, whereas ADP increases by 70% and the ATP/ADP ratio decreases from 7.6 to 3.3. At the same time the oxygen-delivery capacity of red blood cells increases by 37% due to an increase of 2.3-BPG level. In the youngest reticulocytes the basic level of cAMP is 2-fold higher, whereas the maximal (-)-isoproterenol-induced accumulation of cAMP is 8-fold higher than in the fraction of most mature reticulocytes. Evidence for the presence of functionally active glucagon-receptors in reticulocytes is presented, with maturational inactivation/disappearance of R2-glucagon receptors.