ISSN:
1573-4919
Keywords:
phosphatidylserine
;
hypoxia
;
hypocapnia
;
development
;
base exchange
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Phosphatidylserine, which is necessary for protein kinase C activity, is synthesized in mammalian tissues by the Ca2+-dependent base exchange enzyme. The synthesis of phosphatidylserine is greater in slices or homogenates of rat cerebral cortex subjected to hypoxia by N2 treatment when compared with O2 plus 5% CO2. An intermediate effect was observed when the treatment was done with N2 plus 5% CO2. Incorporation rates were dependent on Ca2+ in Krebs-Henseleit Ringer bicarbonate medium, being greater with 2 mM Ca2+ than with the same medium prepared without Ca2+. The increase of phosphatidylserine synthesis, due to hypoxia, was, on the contrary, more evident in the medium lacking added Ca2+. Similar results were obtained with the homogenates. This suggests that elevation of intracellular Ca2+, caused by hypocapnia and hypoxia, may be responsible for the greater incorporation of serine into phosphatidylserine. In both cerebrocortical slices and homogenate, [14C]serine incorporation decreased with development both in O2 plus 5% CO2 and N2-treated preparations. However, in younger rats (14–18 days) hypoxia induced a lesser increase of phosphatidylserine than in 40 day old animals. We suggest that a regulatory mechanisms for phosphatidylserine synthesis is established during development and that N2-treatment can increase phosphatidylserine synthesis by interfering with this regulatory mechanism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00925687
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