Effects of hypoxic hypoxia on the kinetics of synaptosomal Ca2+-ATPase activity in newborn piglets and young rabbits.
Severe hypoxic hypoxia with electrophysiologically detectable involvement of the brain caused a distinct alteration of synaptosomal membrane Ca2+ATPase activity in newborn piglets (n = 7) and young rabbits (n = 7). This was shown by means of the shifted pCa2+ for maximum stimulation towards higher Ca2+ concentrations and a significant decrease of the maximum activity in both species. Furthermore, an additional stimulation using supramaximum amount of exogeneous calmodulin (tested on piglets) was completely abolished after hypoxia. It is suggested that this effect might influence the fine regulation of neuronal Ca2+ homeostasis also during the posthypoxic recovery period.
Schaller
R
R
Institute of Pathological Physiology, Friedrich Schiller University Jena, GDR.
Bauer
R
R
Kluge
H
H
Zwiener
U
U
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002534:Hypoxia, Brain / Q000201:enzymology*; D007700:Kinetics; D011817:Rabbits; D012016:Reference Values; D013552:Swine; D013574:Synaptosomes / Q000201:enzymology*
D000252:Calcium-Transporting ATPases; D002118:Calcium